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Create README.md rather than txt format #1

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@franzejr franzejr commented Dec 3, 2015

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@jrose-apple
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Per the LLVM and Swift section of the Contributing guidelines, we try not to diverge from upstream LLVM, even if it means some things are a little rougher. I think we should leave this one as is.

@jrose-apple jrose-apple closed this Dec 3, 2015
fredriss pushed a commit that referenced this pull request Feb 3, 2016
…ng loads.

According to git bisect, this is the root cause of a miscompile for Regex in
libLLVMSupport. I am still working on reducing a test case.
The actual bug may be elsewhere and this commit just exposed it.

Anyway, at the moment, to reproduce, follow these steps:
1. Build clang and libLTO in release mode.
2. Create a new build directory <stage2> and cd into it.
3. Use clang and libLTO from #1 to build llvm-extract in Release mode + asserts
   using -O2 -flto
4. Run llvm-extract  -ralias '.*bar' -S test/Other/extract-alias.ll

Result:
program doesn't contain global named '.*bar'!

Expected result:
@a0a0bar = alias void ()* @bar
@a0bar = alias void ()* @bar

declare void @bar()

Note: In step #3, if you don't use lto or asserts, the miscompile disappears.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@259674 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Feb 24, 2016
Summary:
For instance, compiling the below results in a panic:

```
llc: ../lib/CodeGen/InlineSpiller.cpp:1140: bool (anonymous namespace)::InlineSpiller::foldMemoryOperand(ArrayRef<std::pair<MachineInstr *, unsigned int> >, llvm::MachineInstr *): Assertion `MO->isDead() && "Cannot fold physreg def"' failed.
#0 0x00007f50fbcf353e llvm::sys::PrintStackTrace(llvm::raw_ostream&) /home/h/3rd/llvm/build/../lib/Support/Unix/Signals.inc:321:15
#1 0x00007f50fbcf3929 PrintStackTraceSignalHandler(void*) /home/h/3rd/llvm/build/../lib/Support/Unix/Signals.inc:380:1
#2 0x00007f50fbcf22a3 llvm::sys::RunSignalHandlers() /home/h/3rd/llvm/build/../lib/Support/Signals.cpp:45:5
#3 0x00007f50fbcf3bb4 SignalHandler(int) /home/h/3rd/llvm/build/../lib/Support/Unix/Signals.inc:210:1
#4 0x00007f50fa87a180 (/lib/x86_64-linux-gnu/libc.so.6+0x35180)
#5 0x00007f50fa87a107 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x35107)
#6 0x00007f50fa87b4e8 abort (/lib/x86_64-linux-gnu/libc.so.6+0x364e8)
#7 0x00007f50fa873226 (/lib/x86_64-linux-gnu/libc.so.6+0x2e226)
#8 0x00007f50fa8732d2 (/lib/x86_64-linux-gnu/libc.so.6+0x2e2d2)
#9 0x00007f50fddd9287 (anonymous namespace)::InlineSpiller::foldMemoryOperand(llvm::ArrayRef<std::pair<llvm::MachineInstr*, unsigned int> >, llvm::MachineInstr*) /home/h/3rd/llvm/build/../lib/CodeGen/InlineSpiller.cpp:1141:21
#10 0x00007f50fddd9ee9 (anonymous namespace)::InlineSpiller::spillAroundUses(unsigned int) /home/h/3rd/llvm/build/../lib/CodeGen/InlineSpiller.cpp:1286:9
#11 0x00007f50fddd388b (anonymous namespace)::InlineSpiller::spillAll() /home/h/3rd/llvm/build/../lib/CodeGen/InlineSpiller.cpp:1338:21
#12 0x00007f50fddd221d (anonymous namespace)::InlineSpiller::spill(llvm::LiveRangeEdit&) /home/h/3rd/llvm/build/../lib/CodeGen/InlineSpiller.cpp:1391:3
#13 0x00007f50fdfd921b (anonymous namespace)::RAGreedy::selectOrSplitImpl(llvm::LiveInterval&, llvm::SmallVectorImpl<unsigned int>&, llvm::SmallSet<unsigned int, 16u, std::less<unsigned int> >&, unsigned int) /home/h/3rd/llvm/build/../lib/CodeGen/RegAllocGreedy.cpp:2555:5
#14 0x00007f50fdfd647b (anonymous namespace)::RAGreedy::selectOrSplit(llvm::LiveInterval&, llvm::SmallVectorImpl<unsigned int>&) /home/h/3rd/llvm/build/../lib/CodeGen/RegAllocGreedy.cpp:2221:12
#15 0x00007f50fdfc89f9 llvm::RegAllocBase::allocatePhysRegs() /home/h/3rd/llvm/build/../lib/CodeGen/RegAllocBase.cpp:110:14
#16 0x00007f50fdfd6337 (anonymous namespace)::RAGreedy::runOnMachineFunction(llvm::MachineFunction&) /home/h/3rd/llvm/build/../lib/CodeGen/RegAllocGreedy.cpp:2611:3
#17 0x00007f50fded33ee llvm::MachineFunctionPass::runOnFunction(llvm::Function&) /home/h/3rd/llvm/build/../lib/CodeGen/MachineFunctionPass.cpp:43:3
#18 0x00007f50fd6cdc6f llvm::FPPassManager::runOnFunction(llvm::Function&) /home/h/3rd/llvm/build/../lib/IR/LegacyPassManager.cpp:1550:23
#19 0x00007f50fd6cdf85 llvm::FPPassManager::runOnModule(llvm::Module&) /home/h/3rd/llvm/build/../lib/IR/LegacyPassManager.cpp:1571:16
#20 0x00007f50fd6ce71a (anonymous namespace)::MPPassManager::runOnModule(llvm::Module&) /home/h/3rd/llvm/build/../lib/IR/LegacyPassManager.cpp:1627:23
#21 0x00007f50fd6ce246 llvm::legacy::PassManagerImpl::run(llvm::Module&) /home/h/3rd/llvm/build/../lib/IR/LegacyPassManager.cpp:1730:16
#22 0x00007f50fd6cec31 llvm::legacy::PassManager::run(llvm::Module&) /home/h/3rd/llvm/build/../lib/IR/LegacyPassManager.cpp:1761:3
#23 0x0000000000415bdc compileModule(char**, llvm::LLVMContext&) /home/h/3rd/llvm/build/../tools/llc/llc.cpp:405:5
#24 0x0000000000414571 main /home/h/3rd/llvm/build/../tools/llc/llc.cpp:211:13
#25 0x00007f50fa866b45 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21b45)
#26 0x0000000000414296 _start (/home/h/3rd/llvm/build/bin/llc+0x414296)
Stack dump:
0.	Program arguments: ./bin/llc -mtriple msp430 loadstore.ll 
1.	Running pass 'Function Pass Manager' on module 'loadstore.ll'.
2.	Running pass 'Greedy Register Allocator' on function '@inc'
```

Original IR:

```llvm
%struct.VeryLarge = type { i8, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 }

; Function Attrs: norecurse nounwind
define void @inc(%struct.VeryLarge* noalias nocapture sret %agg.result, %struct.VeryLarge* byval align 1 %s) #0 {
entry:
  %p0 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 0
  %0 = load i8, i8* %p0, align 1, !tbaa !1
  %p1 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 1
  %1 = load i32, i32* %p1, align 1, !tbaa !6
  %p2 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 2
  %2 = load i32, i32* %p2, align 1, !tbaa !7
  %p3 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 3
  %3 = load i32, i32* %p3, align 1, !tbaa !8
  %p4 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 4
  %4 = load i32, i32* %p4, align 1, !tbaa !9
  %p5 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 5
  %5 = load i32, i32* %p5, align 1, !tbaa !10
  %p6 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 6
  %6 = load i32, i32* %p6, align 1, !tbaa !11
  %p7 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 7
  %7 = load i32, i32* %p7, align 1, !tbaa !12
  %p8 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 8
  %8 = load i32, i32* %p8, align 1, !tbaa !13
  %p9 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 9
  %9 = load i32, i32* %p9, align 1, !tbaa !14
  %p10 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 10
  %10 = load i32, i32* %p10, align 1, !tbaa !15
  %p11 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 11
  %11 = load i32, i32* %p11, align 1, !tbaa !16
  %p12 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 12
  %12 = load i32, i32* %p12, align 1, !tbaa !17
  %p13 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 13
  %13 = load i32, i32* %p13, align 1, !tbaa !18
  %p14 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 14
  %14 = load i32, i32* %p14, align 1, !tbaa !19
  %p15 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 15
  %15 = load i32, i32* %p15, align 1, !tbaa !20
  %p16 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 16
  %16 = load i32, i32* %p16, align 1, !tbaa !21
  %p17 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 17
  %17 = load i32, i32* %p17, align 1, !tbaa !22
  %p18 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 18
  %18 = load i32, i32* %p18, align 1, !tbaa !23
  %p19 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 19
  %19 = load i32, i32* %p19, align 1, !tbaa !24
  %p20 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 20
  %20 = load i32, i32* %p20, align 1, !tbaa !25
  %p21 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 21
  %21 = load i32, i32* %p21, align 1, !tbaa !26
  %p22 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 22
  %22 = load i32, i32* %p22, align 1, !tbaa !27
  %p23 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 23
  %23 = load i32, i32* %p23, align 1, !tbaa !28
  %p24 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 24
  %24 = load i32, i32* %p24, align 1, !tbaa !29
  %p25 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 25
  %25 = load i32, i32* %p25, align 1, !tbaa !30
  %p26 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 26
  %26 = load i32, i32* %p26, align 1, !tbaa !31
  %p27 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 27
  %27 = load i32, i32* %p27, align 1, !tbaa !32
  %p28 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 28
  %28 = load i32, i32* %p28, align 1, !tbaa !33
  %p29 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 29
  %29 = load i32, i32* %p29, align 1, !tbaa !34
  %p30 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 30
  %30 = load i32, i32* %p30, align 1, !tbaa !35
  %p31 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 31
  %31 = load i32, i32* %p31, align 1, !tbaa !36
  %p32 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %s, i32 0, i32 32
  %32 = load i32, i32* %p32, align 1, !tbaa !37
  %add = add i8 %0, 1
  store i8 %add, i8* %p0, align 1, !tbaa !1
  %add2 = add i32 %1, 2
  store i32 %add2, i32* %p1, align 1, !tbaa !6
  %add3 = add i32 %2, 3
  store i32 %add3, i32* %p2, align 1, !tbaa !7
  %add4 = add i32 %3, 4
  store i32 %add4, i32* %p3, align 1, !tbaa !8
  %add5 = add i32 %4, 5
  store i32 %add5, i32* %p4, align 1, !tbaa !9
  %add6 = add i32 %5, 6
  store i32 %add6, i32* %p5, align 1, !tbaa !10
  %add7 = add i32 %6, 7
  store i32 %add7, i32* %p6, align 1, !tbaa !11
  %add8 = add i32 %7, 8
  store i32 %add8, i32* %p7, align 1, !tbaa !12
  %add9 = add i32 %8, 9
  store i32 %add9, i32* %p8, align 1, !tbaa !13
  %add10 = add i32 %9, 10
  store i32 %add10, i32* %p9, align 1, !tbaa !14
  %add11 = add i32 %10, 11
  store i32 %add11, i32* %p10, align 1, !tbaa !15
  %add12 = add i32 %11, 12
  store i32 %add12, i32* %p11, align 1, !tbaa !16
  %add13 = add i32 %12, 13
  store i32 %add13, i32* %p12, align 1, !tbaa !17
  %add14 = add i32 %13, 14
  store i32 %add14, i32* %p13, align 1, !tbaa !18
  %add15 = add i32 %14, 15
  store i32 %add15, i32* %p14, align 1, !tbaa !19
  %add16 = add i32 %15, 16
  store i32 %add16, i32* %p15, align 1, !tbaa !20
  %add17 = add i32 %16, 17
  store i32 %add17, i32* %p16, align 1, !tbaa !21
  %add18 = add i32 %17, 18
  store i32 %add18, i32* %p17, align 1, !tbaa !22
  %add19 = add i32 %18, 19
  store i32 %add19, i32* %p18, align 1, !tbaa !23
  %add20 = add i32 %19, 20
  store i32 %add20, i32* %p19, align 1, !tbaa !24
  %add21 = add i32 %20, 21
  store i32 %add21, i32* %p20, align 1, !tbaa !25
  %add22 = add i32 %21, 22
  store i32 %add22, i32* %p21, align 1, !tbaa !26
  %add23 = add i32 %22, 23
  store i32 %add23, i32* %p22, align 1, !tbaa !27
  %add24 = add i32 %23, 24
  store i32 %add24, i32* %p23, align 1, !tbaa !28
  %add25 = add i32 %24, 25
  store i32 %add25, i32* %p24, align 1, !tbaa !29
  %add26 = add i32 %25, 26
  store i32 %add26, i32* %p25, align 1, !tbaa !30
  %add27 = add i32 %26, 27
  store i32 %add27, i32* %p26, align 1, !tbaa !31
  %add28 = add i32 %27, 28
  store i32 %add28, i32* %p27, align 1, !tbaa !32
  %add29 = add i32 %28, 29
  store i32 %add29, i32* %p28, align 1, !tbaa !33
  %add30 = add i32 %29, 30
  store i32 %add30, i32* %p29, align 1, !tbaa !34
  %add31 = add i32 %30, 31
  store i32 %add31, i32* %p30, align 1, !tbaa !35
  %add32 = add i32 %31, 32
  store i32 %add32, i32* %p31, align 1, !tbaa !36
  %add33 = add i32 %32, 33
  store i32 %add33, i32* %p32, align 1, !tbaa !37
  %33 = getelementptr inbounds %struct.VeryLarge, %struct.VeryLarge* %agg.result, i32 0, i32 0
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %33, i8* %p0, i32 129, i32 1, i1 false), !tbaa.struct !38
  ret void
}

; Function Attrs: argmemonly nounwind
declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture readonly, i32, i32, i1) #1

attributes #0 = { norecurse nounwind "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { argmemonly nounwind }

!llvm.ident = !{!0}

!0 = !{!"clang version 3.8.0 (git://github.com/llvm-mirror/clang 40ef2b7531472c41212c4719a9294aeb7bddebbc) (git://github.com/llvm-mirror/llvm c601eaf55606dfb9ad372b514b77aa00d1409be1)"}
!1 = !{!2, !3, i64 0}
!2 = !{!"", !3, i64 0, !5, i64 1, !5, i64 5, !5, i64 9, !5, i64 13, !5, i64 17, !5, i64 21, !5, i64 25, !5, i64 29, !5, i64 33, !5, i64 37, !5, i64 41, !5, i64 45, !5, i64 49, !5, i64 53, !5, i64 57, !5, i64 61, !5, i64 65, !5, i64 69, !5, i64 73, !5, i64 77, !5, i64 81, !5, i64 85, !5, i64 89, !5, i64 93, !5, i64 97, !5, i64 101, !5, i64 105, !5, i64 109, !5, i64 113, !5, i64 117, !5, i64 121, !5, i64 125}
!3 = !{!"omnipotent char", !4, i64 0}
!4 = !{!"Simple C/C++ TBAA"}
!5 = !{!"int", !3, i64 0}
!6 = !{!2, !5, i64 1}
!7 = !{!2, !5, i64 5}
!8 = !{!2, !5, i64 9}
!9 = !{!2, !5, i64 13}
!10 = !{!2, !5, i64 17}
!11 = !{!2, !5, i64 21}
!12 = !{!2, !5, i64 25}
!13 = !{!2, !5, i64 29}
!14 = !{!2, !5, i64 33}
!15 = !{!2, !5, i64 37}
!16 = !{!2, !5, i64 41}
!17 = !{!2, !5, i64 45}
!18 = !{!2, !5, i64 49}
!19 = !{!2, !5, i64 53}
!20 = !{!2, !5, i64 57}
!21 = !{!2, !5, i64 61}
!22 = !{!2, !5, i64 65}
!23 = !{!2, !5, i64 69}
!24 = !{!2, !5, i64 73}
!25 = !{!2, !5, i64 77}
!26 = !{!2, !5, i64 81}
!27 = !{!2, !5, i64 85}
!28 = !{!2, !5, i64 89}
!29 = !{!2, !5, i64 93}
!30 = !{!2, !5, i64 97}
!31 = !{!2, !5, i64 101}
!32 = !{!2, !5, i64 105}
!33 = !{!2, !5, i64 109}
!34 = !{!2, !5, i64 113}
!35 = !{!2, !5, i64 117}
!36 = !{!2, !5, i64 121}
!37 = !{!2, !5, i64 125}
!38 = !{i64 0, i64 1, !39, i64 1, i64 4, !40, i64 5, i64 4, !40, i64 9, i64 4, !40, i64 13, i64 4, !40, i64 17, i64 4, !40, i64 21, i64 4, !40, i64 25, i64 4, !40, i64 29, i64 4, !40, i64 33, i64 4, !40, i64 37, i64 4, !40, i64 41, i64 4, !40, i64 45, i64 4, !40, i64 49, i64 4, !40, i64 53, i64 4, !40, i64 57, i64 4, !40, i64 61, i64 4, !40, i64 65, i64 4, !40, i64 69, i64 4, !40, i64 73, i64 4, !40, i64 77, i64 4, !40, i64 81, i64 4, !40, i64 85, i64 4, !40, i64 89, i64 4, !40, i64 93, i64 4, !40, i64 97, i64 4, !40, i64 101, i64 4, !40, i64 105, i64 4, !40, i64 109, i64 4, !40, i64 113, i64 4, !40, i64 117, i64 4, !40, i64 121, i64 4, !40, i64 125, i64 4, !40}
!39 = !{!3, !3, i64 0}
!40 = !{!5, !5, i64 0}
```



Reviewers: asl

Subscribers: qcolombet

Differential Revision: http://reviews.llvm.org/D17441

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261746 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Mar 21, 2016
This introduces a custom lowering for ISD::SETCCE (introduced in r253572)
that allows us to emit a short code sequence for 64-bit compares.

Before:

	push	{r7, lr}
	cmp	r0, r2
	mov.w	r0, #0
	mov.w	r12, #0
	it	hs
	movhs	r0, #1
	cmp	r1, r3
	it	ge
	movge.w	r12, #1
	it	eq
	moveq	r12, r0
	cmp.w	r12, #0
	bne	.LBB1_2
@ BB#1:                                 @ %bb1
	bl	f
	pop	{r7, pc}
.LBB1_2:                                @ %bb2
	bl	g
	pop	{r7, pc}

After:

	push	{r7, lr}
	subs	r0, r0, r2
	sbcs.w	r0, r1, r3
	bge	.LBB1_2
@ BB#1:                                 @ %bb1
	bl	f
	pop	{r7, pc}
.LBB1_2:                                @ %bb2
	bl	g
	pop	{r7, pc}

Saves around 80KB in Chromium's libchrome.so.

Some notes on this patch:

- I don't much like the ARMISD::BRCOND and ARMISD::CMOV combines I
  introduced (nothing else needs them). However, they are necessary in
  order to avoid poor codegen, and they seem similar to existing combines
  in other backends (e.g. X86 combines (brcond (cmp (setcc Compare))) to
  (brcond Compare)).

- No support for Thumb-1. This is in principle possible, but we'd need
  to implement ARMISD::SUBE for Thumb-1.

Differential Revision: http://reviews.llvm.org/D15256

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@263962 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Mar 31, 2016
This change prevents the loop vectorizer from vectorizing when all of the vector
types it generates will be scalarized. I've run into this problem on the PPC's QPX
vector ISA, which only holds floating-point vector types. The loop vectorizer
will, however, happily vectorize loops with purely integer computation. Here's
an example:

  LV: The Smallest and Widest types: 32 / 32 bits.
  LV: The Widest register is: 256 bits.
  LV: Found an estimated cost of 0 for VF 1 For instruction:   %indvars.iv25 = phi i64 [ 0, %entry ], [ %indvars.iv.next26, %for.body ]
  LV: Found an estimated cost of 0 for VF 1 For instruction:   %arrayidx = getelementptr inbounds [1600 x i32], [1600 x i32]* %a, i64 0, i64 %indvars.iv25
  LV: Found an estimated cost of 0 for VF 1 For instruction:   %2 = trunc i64 %indvars.iv25 to i32
  LV: Found an estimated cost of 1 for VF 1 For instruction:   store i32 %2, i32* %arrayidx, align 4
  LV: Found an estimated cost of 1 for VF 1 For instruction:   %indvars.iv.next26 = add nuw nsw i64 %indvars.iv25, 1
  LV: Found an estimated cost of 1 for VF 1 For instruction:   %exitcond27 = icmp eq i64 %indvars.iv.next26, 1600
  LV: Found an estimated cost of 0 for VF 1 For instruction:   br i1 %exitcond27, label %for.cond.cleanup, label %for.body
  LV: Scalar loop costs: 3.
  LV: Found an estimated cost of 0 for VF 2 For instruction:   %indvars.iv25 = phi i64 [ 0, %entry ], [ %indvars.iv.next26, %for.body ]
  LV: Found an estimated cost of 0 for VF 2 For instruction:   %arrayidx = getelementptr inbounds [1600 x i32], [1600 x i32]* %a, i64 0, i64 %indvars.iv25
  LV: Found an estimated cost of 0 for VF 2 For instruction:   %2 = trunc i64 %indvars.iv25 to i32
  LV: Found an estimated cost of 2 for VF 2 For instruction:   store i32 %2, i32* %arrayidx, align 4
  LV: Found an estimated cost of 1 for VF 2 For instruction:   %indvars.iv.next26 = add nuw nsw i64 %indvars.iv25, 1
  LV: Found an estimated cost of 1 for VF 2 For instruction:   %exitcond27 = icmp eq i64 %indvars.iv.next26, 1600
  LV: Found an estimated cost of 0 for VF 2 For instruction:   br i1 %exitcond27, label %for.cond.cleanup, label %for.body
  LV: Vector loop of width 2 costs: 2.
  LV: Found an estimated cost of 0 for VF 4 For instruction:   %indvars.iv25 = phi i64 [ 0, %entry ], [ %indvars.iv.next26, %for.body ]
  LV: Found an estimated cost of 0 for VF 4 For instruction:   %arrayidx = getelementptr inbounds [1600 x i32], [1600 x i32]* %a, i64 0, i64 %indvars.iv25
  LV: Found an estimated cost of 0 for VF 4 For instruction:   %2 = trunc i64 %indvars.iv25 to i32
  LV: Found an estimated cost of 4 for VF 4 For instruction:   store i32 %2, i32* %arrayidx, align 4
  LV: Found an estimated cost of 1 for VF 4 For instruction:   %indvars.iv.next26 = add nuw nsw i64 %indvars.iv25, 1
  LV: Found an estimated cost of 1 for VF 4 For instruction:   %exitcond27 = icmp eq i64 %indvars.iv.next26, 1600
  LV: Found an estimated cost of 0 for VF 4 For instruction:   br i1 %exitcond27, label %for.cond.cleanup, label %for.body
  LV: Vector loop of width 4 costs: 1.
  ...
  LV: Selecting VF: 8.
  LV: The target has 32 registers
  LV(REG): Calculating max register usage:
  LV(REG): At #0 Interval # 0
  LV(REG): At #1 Interval # 1
  LV(REG): At #2 Interval # 2
  LV(REG): At #4 Interval # 1
  LV(REG): At #5 Interval # 1
  LV(REG): VF = 8

The problem is that the cost model here is not wrong, exactly. Since all of
these operations are scalarized, their cost (aside from the uniform ones) are
indeed VF*(scalar cost), just as the model suggests. In fact, the larger the VF
picked, the lower the relative overhead from the loop itself (and the
induction-variable update and check), and so in a sense, picking the largest VF
here is the right thing to do.

The problem is that vectorizing like this, where all of the vectors will be
scalarized in the backend, isn't really vectorizing, but rather interleaving.
By itself, this would be okay, but then the vectorizer itself also interleaves,
and that's where the problem manifests itself. There's aren't actually enough
scalar registers to support the normal interleave factor multiplied by a factor
of VF (8 in this example). In other words, the problem with this is that our
register-pressure heuristic does not account for scalarization.

While we might want to improve our register-pressure heuristic, I don't think
this is the right motivating case for that work. Here we have a more-basic
problem: The job of the vectorizer is to vectorize things (interleaving aside),
and if the IR it generates won't generate any actual vector code, then
something is wrong. Thus, if every type looks like it will be scalarized (i.e.
will be split into VF or more parts), then don't consider that VF.

This is not a problem specific to PPC/QPX, however. The problem comes up under
SSE on x86 too, and as such, this change fixes PR26837 too. I've added Sanjay's
reduced test case from PR26837 to this commit.

Differential Revision: http://reviews.llvm.org/D18537

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264904 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Apr 7, 2016
A virtual register may have either a register bank or a register class.
This is represented by a PointerUnion between the related classes.

Typically, a virtual register went through the following states
regarding register class and register bank:

1. Creation: None is set. Virtual registers are fully generic.
2. Register bank assignment: Register bank is set. Virtual registers
live into a register bank, but we do not know the constraints they need
to fulfil.
3. Instruction selection: Register class is set. Virtual registers are
bound by encoding constraints.

To map these states to GlobalISel, the IRTranslator implements #1,
RegBankSelect #2, and Select #3.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265696 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request May 5, 2016
Summary: This reverts commit d88cc08.

#0 0xfed467 in llvm::ARMFrameLowering::determineCalleeSaves(llvm::MachineFunction&, llvm::BitVector&, llvm::RegScavenger*) const /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/Target/ARM/ARMFrameLowering.cpp:1625:52
#1 0x330d4cc in (anonymous namespace)::PEI::runOnMachineFunction(llvm::MachineFunction&) /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/CodeGen/PrologEpilogInserter.cpp:186:3
#2 0x3193e12 in llvm::MachineFunctionPass::runOnFunction(llvm::Function&) /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/CodeGen/MachineFunctionPass.cpp:60:13
#3 0x396237d in llvm::FPPassManager::runOnFunction(llvm::Function&) /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/LegacyPassManager.cpp:1526:23
#4 0x3962a23 in llvm::FPPassManager::runOnModule(llvm::Module&) /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/LegacyPassManager.cpp:1547:16
#5 0x3963d52 in runOnModule /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/LegacyPassManager.cpp:1603:23
#6 0x3963d52 in llvm::legacy::PassManagerImpl::run(llvm::Module&) /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/LegacyPassManager.cpp:1706
#7 0x6bb910 in compileModule(char**, llvm::LLVMContext&) /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/tools/llc/llc.cpp:412:5
#8 0x6b3c25 in main /mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm/tools/llc/llc.cpp:218:22
#9 0x7fd4a7d37ec4 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21ec4)
#10 0x625c93 in _start (/mnt/b/sanitizer-buildbot2/sanitizer-x86_64-linux-bootstrap/build/llvm_build_msan/bin/llc+0x625c93)

Reviewers:

Subscribers:

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268536 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Jun 14, 2016
What happened here is that in the new PM there is a bunch of new copying
(actually, moving) and so this reads the HasProfileData member in
situations where it used to not be read.
It used to only be read strictly in the "runOnFunction" method and its
callees, where is *is* initialized (even after my patch).
So this ends up being benign as far as functional behavior of the
compiler (since we set HasProfileData in the "runImpl" method before we
ever make decisions based on it).

It's awesome that UBSan caught this. It highlights one more thing to
watch out for when porting passes.

Sanitizer bot log was:

-- Testing: 17049 tests, 32 threads --
Testing: 0 .. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80..
FAIL: LLVM :: Transforms/JumpThreading/thread-loads.ll (15184 of 17049)
******************** TEST 'LLVM :: Transforms/JumpThreading/thread-loads.ll' FAILED ********************
Script:
--
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm_build_ubsan/./bin/opt < /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/test/Transforms/JumpThreading/thread-loads.ll -jump-threading -S | /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm_build_ubsan/./bin/FileCheck /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/test/Transforms/JumpThreading/thread-loads.ll
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm_build_ubsan/./bin/opt < /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/test/Transforms/JumpThreading/thread-loads.ll -passes=jump-threading -S | /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm_build_ubsan/./bin/FileCheck /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/test/Transforms/JumpThreading/thread-loads.ll
--
Exit Code: 2

Command Output (stderr):
--
/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/Transforms/Scalar/JumpThreading.h:90:57: runtime error: load of value 136, which is not a valid value for type 'bool'
    #0 0x2c33ba1 in llvm::JumpThreadingPass::JumpThreadingPass(llvm::JumpThreadingPass&&) /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/Transforms/Scalar/JumpThreading.h:90:57
    #1 0x2bc88e4 in void llvm::PassManager<llvm::Function>::addPass<llvm::JumpThreadingPass>(llvm::JumpThreadingPass) /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/PassManager.h:282:40
    #2 0x2bb2682 in llvm::PassBuilder::parseFunctionPassName(llvm::PassManager<llvm::Function>&, llvm::StringRef) /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/Passes/PassRegistry.def:133:1
    #3 0x2bb4914 in llvm::PassBuilder::parseFunctionPassPipeline(llvm::PassManager<llvm::Function>&, llvm::StringRef&, bool, bool) /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/Passes/PassBuilder.cpp:489:12
    #4 0x2bb6f81 in llvm::PassBuilder::parsePassPipeline(llvm::PassManager<llvm::Module>&, llvm::StringRef, bool, bool) /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/lib/Passes/PassBuilder.cpp:674:10
    #5 0x986690 in llvm::runPassPipeline(llvm::StringRef, llvm::LLVMContext&, llvm::Module&, llvm::TargetMachine*, llvm::tool_output_file*, llvm::StringRef, llvm::opt_tool::OutputKind, llvm::opt_tool::VerifierKind, bool, bool) /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/tools/opt/NewPMDriver.cpp:85:8
    #6 0x9af25e in main /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/tools/opt/opt.cpp:468:12
    #7 0x7fd7e27dbf44 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21f44)
    #8 0x960157 in _start (/mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm_build_ubsan/bin/opt+0x960157)

FileCheck error: '-' is empty.
FileCheck command line:  /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm_build_ubsan/./bin/FileCheck /mnt/b/sanitizer-buildbot3/sanitizer-x86_64-linux-fast/build/llvm/test/Transforms/JumpThreading/thread-loads.ll

--

********************
Testing: 0 .. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90..
Testing Time: 128.90s
********************
Failing Tests (1):
    LLVM :: Transforms/JumpThreading/thread-loads.ll

  Expected Passes    : 16725
  Expected Failures  : 129
  Unsupported Tests  : 194
  Unexpected Failures: 1

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272616 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Aug 24, 2016
manager, including both plumbing and logic to handle function pass
updates.

There are three fundamentally tied changes here:
1) Plumbing *some* mechanism for updating the CGSCC pass manager as the
   CG changes while passes are running.
2) Changing the CGSCC pass manager infrastructure to have support for
   the underlying graph to mutate mid-pass run.
3) Actually updating the CG after function passes run.

I can separate them if necessary, but I think its really useful to have
them together as the needs of #3 drove #2, and that in turn drove #1.

The plumbing technique is to extend the "run" method signature with
extra arguments. We provide the call graph that intrinsically is
available as it is the basis of the pass manager's IR units, and an
output parameter that records the results of updating the call graph
during an SCC passes's run. Note that "...UpdateResult" isn't a *great*
name here... suggestions very welcome.

I tried a pretty frustrating number of different data structures and such
for the innards of the update result. Every other one failed for one
reason or another. Sometimes I just couldn't keep the layers of
complexity right in my head. The thing that really worked was to just
directly provide access to the underlying structures used to walk the
call graph so that their updates could be informed by the *particular*
nature of the change to the graph.

The technique for how to make the pass management infrastructure cope
with mutating graphs was also something that took a really, really large
number of iterations to get to a place where I was happy. Here are some
of the considerations that drove the design:

- We operate at three levels within the infrastructure: RefSCC, SCC, and
  Node. In each case, we are working bottom up and so we want to
  continue to iterate on the "lowest" node as the graph changes. Look at
  how we iterate over nodes in an SCC running function passes as those
  function passes mutate the CG. We continue to iterate on the "lowest"
  SCC, which is the one that continues to contain the function just
  processed.

- The call graph structure re-uses SCCs (and RefSCCs) during mutation
  events for the *highest* entry in the resulting new subgraph, not the
  lowest. This means that it is necessary to continually update the
  current SCC or RefSCC as it shifts. This is really surprising and
  subtle, and took a long time for me to work out. I actually tried
  changing the call graph to provide the opposite behavior, and it
  breaks *EVERYTHING*. The graph update algorithms are really deeply
  tied to this particualr pattern.

- When SCCs or RefSCCs are split apart and refined and we continually
  re-pin our processing to the bottom one in the subgraph, we need to
  enqueue the newly formed SCCs and RefSCCs for subsequent processing.
  Queuing them presents a few challenges:
  1) SCCs and RefSCCs use wildly different iteration strategies at
     a high level. We end up needing to converge them on worklist
     approaches that can be extended in order to be able to handle the
     mutations.
  2) The order of the enqueuing need to remain bottom-up post-order so
     that we don't get surprising order of visitation for things like
     the inliner.
  3) We need the worklists to have set semantics so we don't duplicate
     things endlessly. We don't need a *persistent* set though because
     we always keep processing the bottom node!!!! This is super, super
     surprising to me and took a long time to convince myself this is
     correct, but I'm pretty sure it is... Once we sink down to the
     bottom node, we can't re-split out the same node in any way, and
     the postorder of the current queue is fixed and unchanging.
  4) We need to make sure that the "current" SCC or RefSCC actually gets
     enqueued here such that we re-visit it because we continue
     processing a *new*, *bottom* SCC/RefSCC.

- We also need the ability to *skip* SCCs and RefSCCs that get merged
  into a larger component. We even need the ability to skip *nodes* from
  an SCC that are no longer part of that SCC.

This led to the design you see in the patch which uses SetVector-based
worklists. The RefSCC worklist is always empty until an update occurs
and is just used to handle those RefSCCs created by updates as the
others don't even exist yet and are formed on-demand during the
bottom-up walk. The SCC worklist is pre-populated from the RefSCC, and
we push new SCCs onto it and blacklist existing SCCs on it to get the
desired processing.

We then *directly* update these when updating the call graph as I was
never able to find a satisfactory abstraction around the update
strategy.

Finally, we need to compute the updates for function passes. This is
mostly used as an initial customer of all the update mechanisms to drive
their design to at least cover some real set of use cases. There are
a bunch of interesting things that came out of doing this:

- It is really nice to do this a function at a time because that
  function is likely hot in the cache. This means we want even the
  function pass adaptor to support online updates to the call graph!

- To update the call graph after arbitrary function pass mutations is
  quite hard. We have to build a fairly comprehensive set of
  data structures and then process them. Fortunately, some of this code
  is related to the code for building the cal graph in the first place.
  Unfortunately, very little of it makes any sense to share because the
  nature of what we're doing is so very different. I've factored out the
  one part that made sense at least.

- We need to transfer these updates into the various structures for the
  CGSCC pass manager. Once those were more sanely worked out, this
  became relatively easier. But some of those needs necessitated changes
  to the LazyCallGraph interface to make it significantly easier to
  extract the changed SCCs from an update operation.

- We also need to update the CGSCC analysis manager as the shape of the
  graph changes. When an SCC is merged away we need to clear analyses
  associated with it from the analysis manager which we didn't have
  support for in the analysis manager infrsatructure. New SCCs are easy!
  But then we have the case that the original SCC has its shape changed
  but remains in the call graph. There we need to *invalidate* the
  analyses associated with it.

- We also need to invalidate analyses after we *finish* processing an
  SCC. But the analyses we need to invalidate here are *only those for
  the newly updated SCC*!!! Because we only continue processing the
  bottom SCC, if we split SCCs apart the original one gets invalidated
  once when its shape changes and is not processed farther so its
  analyses will be correct. It is the bottom SCC which continues being
  processed and needs to have the "normal" invalidation done based on
  the preserved analyses set.

All of this is mostly background and context for the changes here.

Many thanks to all the reviewers who helped here. Especially Sanjoy who
caught several interesting bugs in the graph algorithms, David, Sean,
and others who all helped with feedback.

Differential Revision: http://reviews.llvm.org/D21464

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279618 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Sep 6, 2016
This test code previously caused a failure in the module verifier,
because SimplifyCFG created this invalid instruction, which tries to
take the address of inline asm:
  %.sink = select i1 %1, i64 ()* asm "mov $0, #1", "=r", i64 ()* asm %"mov $0, #2", "=r"

This has been fixed recently, presumably by James Molloy's patches that
re-wrote and changed parts of SimplifyCFG, so this patch just adds a
regression test for it.

Differential Revision: https://reviews.llvm.org/D24231



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@280660 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Oct 19, 2016
…ump tables

The TBB and TBH instructions in Thumb-2 allow jump tables to be compressed into sequences of bytes or shorts respectively. These instructions do not exist in Thumb-1, however it is possible to synthesize them out of a sequence of other instructions.

It turns out this sequence is so short that it's almost never a lose for performance and is ALWAYS a significant win for code size.

TBB example:
Before: lsls r0, r0, #2    After: add  r0, pc
        adr  r1, .LJTI0_0         ldrb r0, [r0, #6]
        ldr  r0, [r0, r1]         lsls r0, r0, #1
        mov  pc, r0               add  pc, r0
  => No change in prologue code size or dynamic instruction count. Jump table shrunk by a factor of 4.

The only case that can increase dynamic instruction count is the TBH case:

Before: lsls r0, r4, #2    After: lsls r4, r4, #1
        adr  r1, .LJTI0_0         add  r4, pc
        ldr  r0, [r0, r1]         ldrh r4, [r4, #6]
        mov  pc, r0               lsls r4, r4, #1
                                  add  pc, r4
  => 1 more instruction in prologue. Jump table shrunk by a factor of 2.

So there is an argument that this should be disabled when optimizing for performance (and a TBH needs to be generated). I'm not so sure about that in practice, because on small cores with Thumb-1 performance is often tied to code size. But I'm willing to turn it off when optimizing for performance if people want (also note that TBHs are fairly rare in practice!)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284580 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Oct 27, 2016
…tions.

Instead of

 cmp w0, #1
 orr w8, wzr, #0x1
 cneg w0, w8, ne

we now generate

 cmp w0, #1
 csinv w0, w0, wzr, eq

PR28965

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285217 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Nov 2, 2016
…ump tables

[Reapplying r284580 and r285917 with fix and testing to ensure emitted jump tables for Thumb-1 have 4-byte alignment]

The TBB and TBH instructions in Thumb-2 allow jump tables to be compressed into sequences of bytes or shorts respectively. These instructions do not exist in Thumb-1, however it is possible to synthesize them out of a sequence of other instructions.

It turns out this sequence is so short that it's almost never a lose for performance and is ALWAYS a significant win for code size.

TBB example:
Before: lsls r0, r0, #2    After: add  r0, pc
        adr  r1, .LJTI0_0         ldrb r0, [r0, #6]
        ldr  r0, [r0, r1]         lsls r0, r0, #1
        mov  pc, r0               add  pc, r0
  => No change in prologue code size or dynamic instruction count. Jump table shrunk by a factor of 4.

The only case that can increase dynamic instruction count is the TBH case:

Before: lsls r0, r4, #2    After: lsls r4, r4, #1
        adr  r1, .LJTI0_0         add  r4, pc
        ldr  r0, [r0, r1]         ldrh r4, [r4, #6]
        mov  pc, r0               lsls r4, r4, #1
                                  add  pc, r4
  => 1 more instruction in prologue. Jump table shrunk by a factor of 2.

So there is an argument that this should be disabled when optimizing for performance (and a TBH needs to be generated). I'm not so sure about that in practice, because on small cores with Thumb-1 performance is often tied to code size. But I'm willing to turn it off when optimizing for performance if people want (also note that TBHs are fairly rare in practice!)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285690 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Nov 8, 2016
…line asm register selection on AArch64.

Without this patch, register allocation for the example below fails.

define half @test(half %a1, half %a2) #0 {
entry:
  %0 = tail call half asm "sqrshl ${0:h}, ${1:h}, ${2:h}", "=w,w,w" (half %a1, half %a2) #1
  ret half %0
}

Patch by Florian Hahn.

Differential Revision: https://reviews.llvm.org/D25080



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@286111 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Dec 7, 2016
…Idx. NFC.

Summary:
This is NFC but prevents assertions when PartialMappingIdx is tablegen-erated.
The assumptions were:
1) FirstGPR is 0
2) FirstGPR is the first of the First* enumerators.

GPR32 is changed to 1 to demonstrate that assumption #1 is fixed. #2 will
be covered by a subsequent patch that tablegen-erates information and swaps
the order of GPR and FPR as a side effect.

Depends on D27336

Reviewers: ab, t.p.northover, qcolombet

Subscribers: aemerson, rengolin, vkalintiris, dberris, rovka, llvm-commits

Differential Revision: https://reviews.llvm.org/D27337

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@288812 91177308-0d34-0410-b5e6-96231b3b80d8
joker-eph pushed a commit that referenced this pull request Dec 13, 2016
This reverts r289215 (git SHA1 cb7b86a).  It breaks the ubsan build
because a DenseMap that keys off of `AssertingVH<T>` will hit UB when it
tries to cast the empty and tombstone keys to `T *` (due to insufficient
alignment).

This is the relevant stack trace (thanks to Mike Aizatsky):

    #0 0x25cf100 in llvm::AssertingVH<llvm::PHINode>::getValPtr() const llvm/include/llvm/IR/ValueHandle.h:212:39
    #1 0x25cea20 in llvm::AssertingVH<llvm::PHINode>::operator=(llvm::AssertingVH<llvm::PHINode> const&) llvm/include/llvm/IR/ValueHandle.h:234:19
    #2 0x25d0092 in llvm::DenseMapBase<llvm::DenseMap<llvm::AssertingVH<llvm::PHINode>, llvm::detail::DenseSetEmpty, llvm::DenseMapInfo<llvm::AssertingVH<llvm::PHINode> >, llvm::detail::DenseSetPair<llvm::AssertingVH<llvm::PHINode> > >, llvm::AssertingVH<llvm::PHINode>, llvm::detail::DenseSetEmpty, llvm::DenseMapInfo<llvm::AssertingVH<llvm::PHINode> >, llvm::detail::DenseSetPair<llvm::AssertingVH<llvm::PHINode> > >::clear() llvm/include/llvm/ADT/DenseMap.h:113:23

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289482 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Dec 14, 2016
This change re-lands r289215, by reverting r289482.  The underlying
issue that caused it to be reverted has been fixed by Tim Northover in
r289496.

Original commit message for r289215:

[SCEVExpander] Use llvm data structures; NFC

Original commit message for r289482:

Revert "[SCEVExpander] Use llvm data structures; NFC"

This reverts r289215 (git SHA1 cb7b86a).  It breaks the ubsan build
because a DenseMap that keys off of `AssertingVH<T>` will hit UB when it
tries to cast the empty and tombstone keys to `T *` (due to insufficient
alignment).

This is the relevant stack trace (thanks to Mike Aizatsky):

    #0 0x25cf100 in llvm::AssertingVH<llvm::PHINode>::getValPtr() const llvm/include/llvm/IR/ValueHandle.h:212:39
    #1 0x25cea20 in llvm::AssertingVH<llvm::PHINode>::operator=(llvm::AssertingVH<llvm::PHINode> const&) llvm/include/llvm/IR/ValueHandle.h:234:19
    #2 0x25d0092 in llvm::DenseMapBase<llvm::DenseMap<llvm::AssertingVH<llvm::PHINode>, llvm::detail::DenseSetEmpty, llvm::DenseMapInfo<llvm::AssertingVH<llvm::PHINode> >, llvm::detail::DenseSetPair<llvm::AssertingVH<llvm::PHINode> > >, llvm::AssertingVH<llvm::PHINode>, llvm::detail::DenseSetEmpty, llvm::DenseMapInfo<llvm::AssertingVH<llvm::PHINode> >, llvm::detail::DenseSetPair<llvm::AssertingVH<llvm::PHINode> > >::clear() llvm/include/llvm/ADT/DenseMap.h:113:23

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289602 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Jan 13, 2017
…aries.

I have two immediate motivations for adding this:
1) It makes writing expectations in tests *dramatically* easier. A
   quick example that is a taste of what is possible:

     std::vector<int> v = ...;
     EXPECT_THAT(v, UnorderedElementsAre(1, 2, 3));

   This checks that v contains '1', '2', and '3' in some order. There
   are a wealth of other helpful matchers like this. They tend to be
   highly generic and STL-friendly so they will in almost all cases work
   out of the box even on custom LLVM data structures.

   I actually find the matcher syntax substantially easier to read even
   for simple assertions:

     EXPECT_THAT(a, Eq(b));
     EXPECT_THAT(b, Ne(c));

   Both of these make it clear what is being *tested* and what is being
   *expected*. With `EXPECT_EQ` this is implicit (the LHS is expected,
   the RHS is tested) and often confusing. With `EXPECT_NE` it is just
   not clear. Even the failure error messages are superior with the
   matcher based expectations.

2) When testing any kind of generic code, you are continually defining
   dummy types with interfaces and then trying to check that the
   interfaces are manipulated in a particular way. This is actually what
   mocks are *good* for -- testing *interface interactions*. With
   generic code, there is often no "fake" or other object that can be
   used.

   For a concrete example of where this is currently causing significant
   pain, look at the pass manager unittests which are riddled with
   counters incremented when methods are called. All of these could be
   replaced with mocks. The result would be more effective at testing
   the code by having tighter constraints. It would be substantially
   more readable and maintainable when updating the code. And the error
   messages on failure would have substantially more information as
   mocks automatically record stack traces and other information *when
   the API is misused* instead of trying to diagnose it after the fact.

I expect that #1 will be the overwhelming majority of the uses of gmock,
but I think that is sufficient to justify having it. I would actually
like to update the coding standards to encourage the use of matchers
rather than any other form of `EXPECT_...` macros as they are IMO
a strict superset in terms of functionality and readability.

I think that #2 is relatively rarely useful, but there *are* cases where
it is useful. Historically, I think misuse of actual mocking as
described in #2 has led to resistance towards this framework. I am
actually sympathetic to this -- mocking can easily be overused. However
I think this is not a significant concern in LLVM. First and foremost,
LLVM has very careful and rare exposure of abstract interfaces or
dependency injection, which are the most prone to abuse with mocks. So
there are few opportunities to abuse them. Second, a large fraction of
LLVM's unittests are testing *generic code* where mocks actually make
tremendous sense. And gmock is well suited to building interfaces that
exercise generic libraries. Finally, I still think we should be willing
to have testing utilities in tree even if they should be used rarely. We
can use code review to help guide the usage here.

For a longer and more complete discussion of this, see the llvm-dev
thread here:
http://lists.llvm.org/pipermail/llvm-dev/2017-January/108672.html

The general consensus seems that this is a reasonable direction to start
down, but that doesn't mean we should race ahead and use this
everywhere. I have one test that is blocked on this to land and that was
specifically used as an example. Before widespread adoption, I'm going
to work up some (brief) guidelines as some of these facilities should be
used sparingly and carefully.

Differential Revision: https://reviews.llvm.org/D28156

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291606 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Jan 28, 2017
    #0 0x89cdeb in operator new[](unsigned long) /code/llvm/projects/compiler-rt/lib/asan/asan_new_delete.cc:84:37
    #1 0x4ec87c4 in llvm::RegisterBankInfo::ValueMapping const* llvm::RegisterBankInfo::getOperandsMapping<llvm::RegisterBankInfo::ValueMapping const* const*>(llvm::RegisterBankInfo::ValueMapping const* const*, llvm::RegisterBankInfo::ValueMapping const* const*) const /code/llvm/lib/CodeGen/GlobalISel/RegisterBankInfo.cpp:297:9
    #2 0x9327ee in llvm::AArch64RegisterBankInfo::getInstrMapping(llvm::MachineInstr const&) const /code/llvm/lib/Target/AArch64/AArch64RegisterBankInfo.cpp:540:30
    #3 0x4eb8d07 in llvm::RegBankSelect::assignInstr(llvm::MachineInstr&) /code/llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp:546:24
    #4 0x4eb9dd2 in llvm::RegBankSelect::runOnMachineFunction(llvm::MachineFunction&) /code/llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp:624:12
    #5 0x3141875 in llvm::MachineFunctionPass::runOnFunction(llvm::Function&) /code/llvm/lib/CodeGen/MachineFunctionPass.cpp:62:13
    #6 0x396128d in llvm::FPPassManager::runOnFunction(llvm::Function&) /code/llvm/lib/IR/LegacyPassManager.cpp:1513:27
    #7 0x3961832 in llvm::FPPassManager::runOnModule(llvm::Module&) /code/llvm/lib/IR/LegacyPassManager.cpp:1534:16
    #8 0x3962540 in runOnModule /code/llvm/lib/IR/LegacyPassManager.cpp:1590:27
    #9 0x3962540 in llvm::legacy::PassManagerImpl::run(llvm::Module&) /code/llvm/lib/IR/LegacyPassManager.cpp:1693
    #10 0x8ae368 in compileModule(char**, llvm::LLVMContext&) /code/llvm/tools/llc/llc.cpp:562:8
    #11 0x8a7a1b in main /code/llvm/tools/llc/llc.cpp:316:22

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293351 91177308-0d34-0410-b5e6-96231b3b80d8
ahmedbougacha pushed a commit that referenced this pull request Feb 1, 2017
    #0 0x89cdeb in operator new[](unsigned long) /code/llvm/projects/compiler-rt/lib/asan/asan_new_delete.cc:84:37
    #1 0x4ec87c4 in llvm::RegisterBankInfo::ValueMapping const* llvm::RegisterBankInfo::getOperandsMapping<llvm::RegisterBankInfo::ValueMapping const* const*>(llvm::RegisterBankInfo::ValueMapping const* const*, llvm::RegisterBankInfo::ValueMapping const* const*) const /code/llvm/lib/CodeGen/GlobalISel/RegisterBankInfo.cpp:297:9
    #2 0x9327ee in llvm::AArch64RegisterBankInfo::getInstrMapping(llvm::MachineInstr const&) const /code/llvm/lib/Target/AArch64/AArch64RegisterBankInfo.cpp:540:30
    #3 0x4eb8d07 in llvm::RegBankSelect::assignInstr(llvm::MachineInstr&) /code/llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp:546:24
    #4 0x4eb9dd2 in llvm::RegBankSelect::runOnMachineFunction(llvm::MachineFunction&) /code/llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp:624:12
    #5 0x3141875 in llvm::MachineFunctionPass::runOnFunction(llvm::Function&) /code/llvm/lib/CodeGen/MachineFunctionPass.cpp:62:13
    #6 0x396128d in llvm::FPPassManager::runOnFunction(llvm::Function&) /code/llvm/lib/IR/LegacyPassManager.cpp:1513:27
    #7 0x3961832 in llvm::FPPassManager::runOnModule(llvm::Module&) /code/llvm/lib/IR/LegacyPassManager.cpp:1534:16
    #8 0x3962540 in runOnModule /code/llvm/lib/IR/LegacyPassManager.cpp:1590:27
    #9 0x3962540 in llvm::legacy::PassManagerImpl::run(llvm::Module&) /code/llvm/lib/IR/LegacyPassManager.cpp:1693
    #10 0x8ae368 in compileModule(char**, llvm::LLVMContext&) /code/llvm/tools/llc/llc.cpp:562:8
    #11 0x8a7a1b in main /code/llvm/tools/llc/llc.cpp:316:22

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@293351 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit dd95f61)
fredriss pushed a commit that referenced this pull request Mar 3, 2017
…tores.

This patch extends the current functionality of the AArch64 redundant copy
elimination pass to handle non-zero cases such as:

BB#0:
  cmp x0, #1
  b.eq .LBB0_1
.LBB0_1:
  orr x0, xzr, #0x1  ; <-- redundant copy; x0 known to hold #1.

Differential Revision: https://reviews.llvm.org/D29344

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296809 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Mar 22, 2017
Summary:
To support negative immediates for certain arithmetic instructions, the
instruction is converted to the inverse instruction with a negated (or inverted)
immediate. For example, "ADD r0, r1, #FFFFFFFF" cannot be encoded as an ADD
instruction.  However, "SUB r0, r1, #1" is equivalent.

These conversions are different from instruction aliases.  An alias maps
several assembler instructions onto one encoding.  A conversion, however, maps
an *invalid* instruction--e.g. with an immediate that cannot be represented in
the encoding--to a different (but equivalent) instruction.

Several instructions with negative immediates were being converted already, but
this was not systematically tested, nor did it cover all instructions.

This patch implements all possible substitutions for ARM, Thumb1 and
Thumb2 assembler and adds tests.  It also adds a feature flag
(-mattr=+no-neg-immediates) to turn these substitutions off.  This is
helpful for users who want their code to assemble to exactly what they
wrote.

Reviewers: t.p.northover, rovka, samparker, javed.absar, peter.smith, rengolin

Reviewed By: javed.absar

Subscribers: aadg, aemerson, llvm-commits

Differential Revision: https://reviews.llvm.org/D30571


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298380 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request May 11, 2017
…merged"

This reverts r302712.

The change fails with ASAN enabled:

ERROR: AddressSanitizer: use-after-poison on address ... at ...
READ of size 2 at ... thread T0
  #0 ... in llvm::SDNode::getNumValues() const <snip>/include/llvm/CodeGen/SelectionDAGNodes.h:855:42
  #1 ... in llvm::SDNode::hasAnyUseOfValue(unsigned int) const <snip>/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:7270:3
  #2 ... in llvm::SDValue::use_empty() const <snip> include/llvm/CodeGen/SelectionDAGNodes.h:1042:17
  #3 ... in (anonymous namespace)::DAGCombiner::MergeConsecutiveStores(llvm::StoreSDNode*) <snip>/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:12944:7

Reviewers: niravd

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D33081

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302746 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request May 18, 2017
There is often a lot of boilerplate code required to visit a type
record or type stream.  The #1 use case is that you have a sequence
of bytes that represent one or more records, and you want to
deserialize each one, switch on it, and call a callback with the
deserialized record that the user can examine.  Currently this
requires at least 6 lines of code:

  codeview::TypeVisitorCallbackPipeline Pipeline;
  Pipeline.addCallbackToPipeline(Deserializer);
  Pipeline.addCallbackToPipeline(MyCallbacks);

  codeview::CVTypeVisitor Visitor(Pipeline);
  consumeError(Visitor.visitTypeRecord(Record));

With this patch, it becomes one line of code:

  consumeError(codeview::visitTypeRecord(Record, MyCallbacks));

This is done by having the deserialization happen internally inside
of the visitTypeRecord function.  Since this is occasionally not
desirable, the function provides a 3rd parameter that can be used
to change this behavior.

Hopefully this can significantly reduce the barrier to entry
to using the visitation infrastructure.

Differential Revision: https://reviews.llvm.org/D33245

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@303271 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request May 30, 2017
error C2971: 'llvm::ManagedStatic': template parameter 'Creator': 'CreateDefaultTimerGroup': a variable with non-static storage duration cannot be used as a non-type argument

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304157 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Jun 3, 2017
…ruction

Op1 (RHS) is a constant, so putting it on the LHS makes us churn through visitICmp
an extra time to canonicalize it:

INSTCOMBINE ITERATION #1 on cmpnot
IC: ADDING: 3 instrs to worklist
IC: Visiting:   %notx = xor i8 %x, -1
IC: Visiting:   %cmp = icmp sgt i8 %notx, 42
IC: Old =   %cmp = icmp sgt i8 %notx, 42
    New =   <badref> = icmp sgt i8 -43, %x
IC: ADD:   %cmp = icmp sgt i8 -43, %x
IC: ERASE   %1 = icmp sgt i8 %notx, 42
IC: ADD:   %notx = xor i8 %x, -1
IC: DCE:   %notx = xor i8 %x, -1
IC: ERASE   %notx = xor i8 %x, -1
IC: Visiting:   %cmp = icmp sgt i8 -43, %x
IC: Mod =   %cmp = icmp sgt i8 -43, %x
    New =   %cmp = icmp slt i8 %x, -43
IC: ADD:   %cmp = icmp slt i8 %x, -43
IC: Visiting:   %cmp = icmp slt i8 %x, -43
IC: Visiting:   ret i1 %cmp

If we create the swapped ICmp directly, we go faster:

INSTCOMBINE ITERATION #1 on cmpnot
IC: ADDING: 3 instrs to worklist
IC: Visiting:   %notx = xor i8 %x, -1
IC: Visiting:   %cmp = icmp sgt i8 %notx, 42
IC: Old =   %cmp = icmp sgt i8 %notx, 42
    New =   <badref> = icmp slt i8 %x, -43
IC: ADD:   %cmp = icmp slt i8 %x, -43
IC: ERASE   %1 = icmp sgt i8 %notx, 42
IC: ADD:   %notx = xor i8 %x, -1
IC: DCE:   %notx = xor i8 %x, -1
IC: ERASE   %notx = xor i8 %x, -1
IC: Visiting:   %cmp = icmp slt i8 %x, -43
IC: Visiting:   ret i1 %cmp




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304558 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Oct 10, 2017
Summary:
This updates the SCCP solver to use of the ValueElement lattice for 
parameters, which provides integer range information. The range
information is used to remove unneeded icmp instructions.

For the following function, f() can be optimized to `ret i32 2` with
this change

  source_filename = "sccp.c"
  target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
  target triple = "x86_64-unknown-linux-gnu"
  
  ; Function Attrs: norecurse nounwind readnone uwtable
  define i32 @main() local_unnamed_addr #0 {
  entry:
    %call = tail call fastcc i32 @f(i32 1)
    %call1 = tail call fastcc i32 @f(i32 47)
    %add3 = add nsw i32 %call, %call1
    ret i32 %add3
  }
  
  ; Function Attrs: noinline norecurse nounwind readnone uwtable
  define internal fastcc i32 @f(i32 %x) unnamed_addr #1 {
  entry:
    %c1 = icmp sle i32 %x, 100
  
    %cmp = icmp sgt i32 %x, 300
    %. = select i1 %cmp, i32 1, i32 2
    ret i32 %.
  }
  
  attributes #1 = { noinline }



Reviewers: davide, sanjoy, efriedma, dberlin

Reviewed By: davide, dberlin

Subscribers: mcrosier, gberry, mssimpso, dberlin, llvm-commits

Differential Revision: https://reviews.llvm.org/D36656

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315288 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Oct 13, 2017
…SCCP."

This is r315288 & r315294, which were reverted due to stage2 bot
failures.

Summary:
This updates the SCCP solver to use of the ValueElement lattice for
parameters, which provides integer range information. The range
information is used to remove unneeded icmp instructions.

For the following function, f() can be optimized to `ret i32 2` with
this change

  source_filename = "sccp.c"
  target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
  target triple = "x86_64-unknown-linux-gnu"

  ; Function Attrs: norecurse nounwind readnone uwtable
  define i32 @main() local_unnamed_addr #0 {
  entry:
    %call = tail call fastcc i32 @f(i32 1)
    %call1 = tail call fastcc i32 @f(i32 47)
    %add3 = add nsw i32 %call, %call1
    ret i32 %add3
  }

  ; Function Attrs: noinline norecurse nounwind readnone uwtable
  define internal fastcc i32 @f(i32 %x) unnamed_addr #1 {
  entry:
    %c1 = icmp sle i32 %x, 100

    %cmp = icmp sgt i32 %x, 300
    %. = select i1 %cmp, i32 1, i32 2
    ret i32 %.
  }

  attributes #1 = { noinline }

Reviewers: davide, sanjoy, efriedma, dberlin

Reviewed By: davide, dberlin

Subscribers: mcrosier, gberry, mssimpso, dberlin, llvm-commits

Differential Revision: https://reviews.llvm.org/D36656

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315593 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Jul 21, 2018
A DAG-NOT-DAG is a CHECK-DAG group, X, followed by a CHECK-NOT group,
N, followed by a CHECK-DAG group, Y.  Let y be the initial directive
of Y.  This patch makes the following changes to the behavior:

    1. Directives in N can no longer match within part of Y's match
       range just because y happens not to be the earliest match from
       Y.  Specifically, this patch withdraws N's search range end
       from y's match range start to Y's match range start.

    2. y can no longer match within X's match range, where a y match
       produced a reordering complaint, which is thus no longer
       possible.  Specifically, this patch withdraws y's search range
       start from X's permitted range start to X's match range end,
       which was already the search range start for other members of
       Y.

Both of these changes can only increase the number of test passes: #1
constrains the ability of CHECK-NOTs to match, and #2 expands the
ability of CHECK-DAGs to match without complaints.

These changes are based on discussions at:

   <http://lists.llvm.org/pipermail/llvm-dev/2018-May/123550.html>
   <https://reviews.llvm.org/D47106>

which conclude that:

    1. These changes simplify the FileCheck conceptual model.  First,
       it makes search ranges for DAG-NOT-DAG more consistent with
       other cases.  Second, it was confusing that y was treated
       differently from the rest of Y.

    2. These changes add theoretical use cases for DAG-NOT-DAG that
       had no obvious means to be expressed otherwise.  We can justify
       the first half of this assertion with the observation that
       these changes can only increase the number of test passes.

    3. Reordering detection for DAG-NOT-DAG had no obvious real
       benefit.

We don't have evidence from real uses cases to help us debate
conclusions #2 and #3, but #1 at least seems intuitive.

Reviewed By: probinson

Differential Revision: https://reviews.llvm.org/D48986

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337605 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Aug 9, 2018
Summary:
Currently, in line with GCC, when specifying reserved registers like sp or pc on an inline asm() clobber list, we don't always preserve the original value across the statement. And in general, overwriting reserved registers can have surprising results.

For example:


```
extern int bar(int[]);

int foo(int i) {
  int a[i]; // VLA
  asm volatile(
      "mov r7, #1"
    :
    :
    : "r7"
  );

  return 1 + bar(a);
}
```

Compiled for thumb, this gives:
```
$ clang --target=arm-arm-none-eabi -march=armv7a -c test.c -o - -S -O1 -mthumb
...
foo:
        .fnstart
@ %bb.0:                                @ %entry
        .save   {r4, r5, r6, r7, lr}
        push    {r4, r5, r6, r7, lr}
        .setfp  r7, sp, #12
        add     r7, sp, #12
        .pad    #4
        sub     sp, #4
        movs    r1, #7
        add.w   r0, r1, r0, lsl #2
        bic     r0, r0, #7
        sub.w   r0, sp, r0
        mov     sp, r0
        @app
        mov.w   r7, #1
        @NO_APP
        bl      bar
        adds    r0, #1
        sub.w   r4, r7, #12
        mov     sp, r4
        pop     {r4, r5, r6, r7, pc}
...
```

r7 is used as the frame pointer for thumb targets, and this function needs to restore the SP from the FP because of the variable-length stack allocation a. r7 is clobbered by the inline assembly (and r7 is included in the clobber list), but LLVM does not preserve the value of the frame pointer across the assembly block.

This type of behavior is similar to GCC's and has been discussed on the bugtracker: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=11807 . No consensus seemed to have been reached on the way forward.  Clang behavior has briefly been discussed on the CFE mailing (starting here: http://lists.llvm.org/pipermail/cfe-dev/2018-July/058392.html). I've opted for following Eli Friedman's advice to print warnings when there are reserved registers on the clobber list so as not to diverge from GCC behavior for now.

The patch uses MachineRegisterInfo's target-specific knowledge of reserved registers, just before we convert the inline asm string in the AsmPrinter.

If we find a reserved register, we print a warning:
```
repro.c:6:7: warning: inline asm clobber list contains reserved registers: R7 [-Winline-asm]
      "mov r7, #1"
      ^
```

Reviewers: eli.friedman, olista01, javed.absar, efriedma

Reviewed By: efriedma

Subscribers: efriedma, eraman, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D49727

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@339257 91177308-0d34-0410-b5e6-96231b3b80d8
aemerson pushed a commit that referenced this pull request Aug 29, 2018
A DAG-NOT-DAG is a CHECK-DAG group, X, followed by a CHECK-NOT group,
N, followed by a CHECK-DAG group, Y.  Let y be the initial directive
of Y.  This patch makes the following changes to the behavior:

    1. Directives in N can no longer match within part of Y's match
       range just because y happens not to be the earliest match from
       Y.  Specifically, this patch withdraws N's search range end
       from y's match range start to Y's match range start.

    2. y can no longer match within X's match range, where a y match
       produced a reordering complaint, which is thus no longer
       possible.  Specifically, this patch withdraws y's search range
       start from X's permitted range start to X's match range end,
       which was already the search range start for other members of
       Y.

Both of these changes can only increase the number of test passes: #1
constrains the ability of CHECK-NOTs to match, and #2 expands the
ability of CHECK-DAGs to match without complaints.

These changes are based on discussions at:

   <http://lists.llvm.org/pipermail/llvm-dev/2018-May/123550.html>
   <https://reviews.llvm.org/D47106>

which conclude that:

    1. These changes simplify the FileCheck conceptual model.  First,
       it makes search ranges for DAG-NOT-DAG more consistent with
       other cases.  Second, it was confusing that y was treated
       differently from the rest of Y.

    2. These changes add theoretical use cases for DAG-NOT-DAG that
       had no obvious means to be expressed otherwise.  We can justify
       the first half of this assertion with the observation that
       these changes can only increase the number of test passes.

    3. Reordering detection for DAG-NOT-DAG had no obvious real
       benefit.

We don't have evidence from real uses cases to help us debate
conclusions #2 and #3, but #1 at least seems intuitive.

Reviewed By: probinson

Differential Revision: https://reviews.llvm.org/D48986

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337605 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Aug 31, 2018
Summary:
This is a continuation of https://reviews.llvm.org/D49727
Below the original text, current changes in the comments:

Currently, in line with GCC, when specifying reserved registers like sp or pc on an inline asm() clobber list, we don't always preserve the original value across the statement. And in general, overwriting reserved registers can have surprising results.

For example:

  extern int bar(int[]);
  
  int foo(int i) {
    int a[i]; // VLA
    asm volatile(
        "mov r7, #1"
      :
      :
      : "r7"
    );
  
    return 1 + bar(a);
  }

Compiled for thumb, this gives:

  $ clang --target=arm-arm-none-eabi -march=armv7a -c test.c -o - -S -O1 -mthumb
  ...
  foo:
          .fnstart
  @ %bb.0:                                @ %entry
          .save   {r4, r5, r6, r7, lr}
          push    {r4, r5, r6, r7, lr}
          .setfp  r7, sp, #12
          add     r7, sp, #12
          .pad    #4
          sub     sp, #4
          movs    r1, #7
          add.w   r0, r1, r0, lsl #2
          bic     r0, r0, #7
          sub.w   r0, sp, r0
          mov     sp, r0
          @app
          mov.w   r7, #1
          @NO_APP
          bl      bar
          adds    r0, #1
          sub.w   r4, r7, #12
          mov     sp, r4
          pop     {r4, r5, r6, r7, pc}
  ...

r7 is used as the frame pointer for thumb targets, and this function needs to restore the SP from the FP because of the variable-length stack allocation a. r7 is clobbered by the inline assembly (and r7 is included in the clobber list), but LLVM does not preserve the value of the frame pointer across the assembly block.

This type of behavior is similar to GCC's and has been discussed on the bugtracker: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=11807 . No consensus seemed to have been reached on the way forward. Clang behavior has briefly been discussed on the CFE mailing (starting here: http://lists.llvm.org/pipermail/cfe-dev/2018-July/058392.html). I've opted for following Eli Friedman's advice to print warnings when there are reserved registers on the clobber list so as not to diverge from GCC behavior for now.

The patch uses MachineRegisterInfo's target-specific knowledge of reserved registers, just before we convert the inline asm string in the AsmPrinter.

If we find a reserved register, we print a warning:

  repro.c:6:7: warning: inline asm clobber list contains reserved registers: R7 [-Winline-asm]
        "mov r7, #1"
        ^

Reviewers: efriedma, olista01, javed.absar

Reviewed By: efriedma

Subscribers: eraman, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D51165

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@341062 91177308-0d34-0410-b5e6-96231b3b80d8
hyp pushed a commit to hyp/swift-llvm that referenced this pull request Sep 12, 2018
A DAG-NOT-DAG is a CHECK-DAG group, X, followed by a CHECK-NOT group,
N, followed by a CHECK-DAG group, Y.  Let y be the initial directive
of Y.  This patch makes the following changes to the behavior:

    1. Directives in N can no longer match within part of Y's match
       range just because y happens not to be the earliest match from
       Y.  Specifically, this patch withdraws N's search range end
       from y's match range start to Y's match range start.

    2. y can no longer match within X's match range, where a y match
       produced a reordering complaint, which is thus no longer
       possible.  Specifically, this patch withdraws y's search range
       start from X's permitted range start to X's match range end,
       which was already the search range start for other members of
       Y.

Both of these changes can only increase the number of test passes: apple#1
constrains the ability of CHECK-NOTs to match, and apple#2 expands the
ability of CHECK-DAGs to match without complaints.

These changes are based on discussions at:

   <http://lists.llvm.org/pipermail/llvm-dev/2018-May/123550.html>
   <https://reviews.llvm.org/D47106>

which conclude that:

    1. These changes simplify the FileCheck conceptual model.  First,
       it makes search ranges for DAG-NOT-DAG more consistent with
       other cases.  Second, it was confusing that y was treated
       differently from the rest of Y.

    2. These changes add theoretical use cases for DAG-NOT-DAG that
       had no obvious means to be expressed otherwise.  We can justify
       the first half of this assertion with the observation that
       these changes can only increase the number of test passes.

    3. Reordering detection for DAG-NOT-DAG had no obvious real
       benefit.

We don't have evidence from real uses cases to help us debate
conclusions apple#2 and apple#3, but apple#1 at least seems intuitive.

Reviewed By: probinson

Differential Revision: https://reviews.llvm.org/D48986

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337605 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Sep 14, 2018
…uter loops.

Summary:
[VPlan] Implement vector code generation support for simple outer loops.

Context: Patch Series #1 for outer loop vectorization support in LV  using VPlan. (RFC: http://lists.llvm.org/pipermail/llvm-dev/2017-December/119523.html).
                                                          
This patch introduces vector code generation support for simple outer loops that are currently supported in the VPlanNativePath. Changes here essentially do the following:

  - force vector code generation using explicit vectorize_width

  - add conservative early returns in cost model and other places for VPlanNativePath

  - add code for setting up outer loop inductions 

  - support for widening non-induction PHIs that can result from inner loops and uniform conditional branches

  - support for generating uniform inner branches

We plan to add a handful C outer loop executable tests once the initial code generation support is committed. This patch is expected to be NFC for the inner loop vectorizer path. Since we are moving in the direction of supporting outer loop vectorization in LV, it may also be time to rename classes such as InnerLoopVectorizer. 

Reviewers: fhahn, rengolin, hsaito, dcaballe, mkuper, hfinkel, Ayal

Reviewed By: fhahn, hsaito

Subscribers: dmgreen, bollu, tschuett, rkruppe, rogfer01, llvm-commits

Differential Revision: https://reviews.llvm.org/D50820

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342197 91177308-0d34-0410-b5e6-96231b3b80d8
francisvm added a commit that referenced this pull request Oct 8, 2018
…ression

The following instruction:

> str q28, [x0, #1*6*4*@]

contains a @ which is parsed as an empty symbol. The parser returns true
but has no error, so the assembler continues by ignoring the
instruction.

rdar://44534987

Differential Revision: https://reviews.llvm.org/D52645

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@343961 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Oct 9, 2018
…ression

The following instruction:

> str q28, [x0, #1*6*4*@]

contains a @ which is parsed as an empty symbol. The parser returns true
but has no error, so the assembler continues by ignoring the
instruction.

Differential Revision: https://reviews.llvm.org/D52645

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@343961 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Oct 10, 2018
icmp ne (and X, 1), 0 --> trunc X to N x i1

Ideally, we'd do the same for scalars, but there will likely be 
regressions unless we add more trunc folds as we're doing here 
for vectors.

The motivating vector case is from PR37549:
https://bugs.llvm.org/show_bug.cgi?id=37549

define <4 x float> @bitwise_select(<4 x float> %x, <4 x float> %y, <4 x float> %z, <4 x float> %w) {
  %c = fcmp ole <4 x float> %x, %y
  %s = sext <4 x i1> %c to <4 x i32>
  %s1 = shufflevector <4 x i32> %s, <4 x i32> undef, <4 x i32> <i32 0, i32 0, i32 1, i32 1>
  %s2 = shufflevector <4 x i32> %s, <4 x i32> undef, <4 x i32> <i32 2, i32 2, i32 3, i32 3>
  %cond = or <4 x i32> %s1, %s2
  %condtr = trunc <4 x i32> %cond to <4 x i1>
  %r = select <4 x i1> %condtr, <4 x float> %z, <4 x float> %w
  ret <4 x float> %r
}

Here's a sampling of the vector codegen for that case using 
mask+icmp (current behavior) vs. trunc (with this patch):

AVX before:

vcmpleps	%xmm1, %xmm0, %xmm0
vpermilps	$80, %xmm0, %xmm1 ## xmm1 = xmm0[0,0,1,1]
vpermilps	$250, %xmm0, %xmm0 ## xmm0 = xmm0[2,2,3,3]
vorps	%xmm0, %xmm1, %xmm0
vandps	LCPI0_0(%rip), %xmm0, %xmm0
vxorps	%xmm1, %xmm1, %xmm1
vpcmpeqd	%xmm1, %xmm0, %xmm0
vblendvps	%xmm0, %xmm3, %xmm2, %xmm0

AVX after:

vcmpleps	%xmm1, %xmm0, %xmm0
vpermilps	$80, %xmm0, %xmm1 ## xmm1 = xmm0[0,0,1,1]
vpermilps	$250, %xmm0, %xmm0 ## xmm0 = xmm0[2,2,3,3]
vorps	%xmm0, %xmm1, %xmm0
vblendvps	%xmm0, %xmm2, %xmm3, %xmm0

AVX512f before:

vcmpleps	%xmm1, %xmm0, %xmm0
vpermilps	$80, %xmm0, %xmm1 ## xmm1 = xmm0[0,0,1,1]
vpermilps	$250, %xmm0, %xmm0 ## xmm0 = xmm0[2,2,3,3]
vorps	%xmm0, %xmm1, %xmm0
vpbroadcastd	LCPI0_0(%rip), %xmm1 ## xmm1 = [1,1,1,1]
vptestnmd	%zmm1, %zmm0, %k1
vblendmps	%zmm3, %zmm2, %zmm0 {%k1}

AVX512f after:

vcmpleps	%xmm1, %xmm0, %xmm0
vpermilps	$80, %xmm0, %xmm1 ## xmm1 = xmm0[0,0,1,1]
vpermilps	$250, %xmm0, %xmm0 ## xmm0 = xmm0[2,2,3,3]
vorps	%xmm0, %xmm1, %xmm0
vpslld	$31, %xmm0, %xmm0
vptestmd	%zmm0, %zmm0, %k1
vblendmps	%zmm2, %zmm3, %zmm0 {%k1}

AArch64 before:

fcmge	v0.4s, v1.4s, v0.4s
zip1	v1.4s, v0.4s, v0.4s
zip2	v0.4s, v0.4s, v0.4s
orr	v0.16b, v1.16b, v0.16b
movi	v1.4s, #1
and	v0.16b, v0.16b, v1.16b
cmeq	v0.4s, v0.4s, #0
bsl	v0.16b, v3.16b, v2.16b

AArch64 after:

fcmge	v0.4s, v1.4s, v0.4s
zip1	v1.4s, v0.4s, v0.4s
zip2	v0.4s, v0.4s, v0.4s
orr	v0.16b, v1.16b, v0.16b
bsl	v0.16b, v2.16b, v3.16b

PowerPC-le before:

xvcmpgesp 34, 35, 34
vspltisw 0, 1
vmrglw 3, 2, 2
vmrghw 2, 2, 2
xxlor 0, 35, 34
xxlxor 35, 35, 35
xxland 34, 0, 32
vcmpequw 2, 2, 3
xxsel 34, 36, 37, 34

PowerPC-le after:

xvcmpgesp 34, 35, 34
vmrglw 3, 2, 2
vmrghw 2, 2, 2
xxlor 0, 35, 34
xxsel 34, 37, 36, 0

Differential Revision: https://reviews.llvm.org/D52747



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@344082 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Oct 11, 2018
Re-trying r344082 because it unintentionally included extra diffs.

Original commit message:
icmp ne (and X, 1), 0 --> trunc X to N x i1

Ideally, we'd do the same for scalars, but there will likely be
regressions unless we add more trunc folds as we're doing here
for vectors.

The motivating vector case is from PR37549:
https://bugs.llvm.org/show_bug.cgi?id=37549

define <4 x float> @bitwise_select(<4 x float> %x, <4 x float> %y, <4 x float> %z, <4 x float> %w) {

  %c = fcmp ole <4 x float> %x, %y
  %s = sext <4 x i1> %c to <4 x i32>
  %s1 = shufflevector <4 x i32> %s, <4 x i32> undef, <4 x i32> <i32 0, i32 0, i32 1, i32 1>
  %s2 = shufflevector <4 x i32> %s, <4 x i32> undef, <4 x i32> <i32 2, i32 2, i32 3, i32 3>
  %cond = or <4 x i32> %s1, %s2
  %condtr = trunc <4 x i32> %cond to <4 x i1>
  %r = select <4 x i1> %condtr, <4 x float> %z, <4 x float> %w
  ret <4 x float> %r

}

Here's a sampling of the vector codegen for that case using
mask+icmp (current behavior) vs. trunc (with this patch):

AVX before:

vcmpleps        %xmm1, %xmm0, %xmm0
vpermilps       $80, %xmm0, %xmm1 ## xmm1 = xmm0[0,0,1,1]
vpermilps       $250, %xmm0, %xmm0 ## xmm0 = xmm0[2,2,3,3]
vorps   %xmm0, %xmm1, %xmm0
vandps  LCPI0_0(%rip), %xmm0, %xmm0
vxorps  %xmm1, %xmm1, %xmm1
vpcmpeqd        %xmm1, %xmm0, %xmm0
vblendvps       %xmm0, %xmm3, %xmm2, %xmm0

AVX after:

vcmpleps        %xmm1, %xmm0, %xmm0
vpermilps       $80, %xmm0, %xmm1 ## xmm1 = xmm0[0,0,1,1]
vpermilps       $250, %xmm0, %xmm0 ## xmm0 = xmm0[2,2,3,3]
vorps   %xmm0, %xmm1, %xmm0
vblendvps       %xmm0, %xmm2, %xmm3, %xmm0

AVX512f before:

vcmpleps        %xmm1, %xmm0, %xmm0
vpermilps       $80, %xmm0, %xmm1 ## xmm1 = xmm0[0,0,1,1]
vpermilps       $250, %xmm0, %xmm0 ## xmm0 = xmm0[2,2,3,3]
vorps   %xmm0, %xmm1, %xmm0
vpbroadcastd    LCPI0_0(%rip), %xmm1 ## xmm1 = [1,1,1,1]
vptestnmd       %zmm1, %zmm0, %k1
vblendmps       %zmm3, %zmm2, %zmm0 {%k1}

AVX512f after:

vcmpleps        %xmm1, %xmm0, %xmm0
vpermilps       $80, %xmm0, %xmm1 ## xmm1 = xmm0[0,0,1,1]
vpermilps       $250, %xmm0, %xmm0 ## xmm0 = xmm0[2,2,3,3]
vorps   %xmm0, %xmm1, %xmm0
vpslld  $31, %xmm0, %xmm0
vptestmd        %zmm0, %zmm0, %k1
vblendmps       %zmm2, %zmm3, %zmm0 {%k1}

AArch64 before:

fcmge   v0.4s, v1.4s, v0.4s
zip1    v1.4s, v0.4s, v0.4s
zip2    v0.4s, v0.4s, v0.4s
orr     v0.16b, v1.16b, v0.16b
movi    v1.4s, #1
and     v0.16b, v0.16b, v1.16b
cmeq    v0.4s, v0.4s, #0
bsl     v0.16b, v3.16b, v2.16b

AArch64 after:

fcmge   v0.4s, v1.4s, v0.4s
zip1    v1.4s, v0.4s, v0.4s
zip2    v0.4s, v0.4s, v0.4s
orr     v0.16b, v1.16b, v0.16b
bsl     v0.16b, v2.16b, v3.16b

PowerPC-le before:

xvcmpgesp 34, 35, 34
vspltisw 0, 1
vmrglw 3, 2, 2
vmrghw 2, 2, 2
xxlor 0, 35, 34
xxlxor 35, 35, 35
xxland 34, 0, 32
vcmpequw 2, 2, 3
xxsel 34, 36, 37, 34

PowerPC-le after:

xvcmpgesp 34, 35, 34
vmrglw 3, 2, 2
vmrghw 2, 2, 2
xxlor 0, 35, 34
xxsel 34, 37, 36, 0

Differential Revision: https://reviews.llvm.org/D52747



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@344181 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Oct 24, 2018
…>> (32 - y) pattern"

*Seems* to be breaking sanitizer-x86_64-linux-fast buildbot,
the ELF/relocatable-versioned.s test:

==17758==MemorySanitizer CHECK failed: /b/sanitizer-x86_64-linux-fast/build/llvm/projects/compiler-rt/lib/sanitizer_common/sanitizer_allocator.cc:191 "((kBlockMagic)) == ((((u64*)addr)[0]))" (0x6a6cb03abcebc041, 0x0)
    #0 0x59716b in MsanCheckFailed(char const*, int, char const*, unsigned long long, unsigned long long) /b/sanitizer-x86_64-linux-fast/build/llvm/projects/compiler-rt/lib/msan/msan.cc:393
    #1 0x586635 in __sanitizer::CheckFailed(char const*, int, char const*, unsigned long long, unsigned long long) /b/sanitizer-x86_64-linux-fast/build/llvm/projects/compiler-rt/lib/sanitizer_common/sanitizer_termination.cc:79
    #2 0x57d5ff in __sanitizer::InternalFree(void*, __sanitizer::SizeClassAllocatorLocalCache<__sanitizer::SizeClassAllocator32<__sanitizer::AP32> >*) /b/sanitizer-x86_64-linux-fast/build/llvm/projects/compiler-rt/lib/sanitizer_common/sanitizer_allocator.cc:191
    #3 0x7fc21b24193f  (/lib/x86_64-linux-gnu/libc.so.6+0x3593f)
    #4 0x7fc21b241999 in exit (/lib/x86_64-linux-gnu/libc.so.6+0x35999)
    #5 0x7fc21b22c2e7 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e7)
    #6 0x57c039 in _start (/b/sanitizer-x86_64-linux-fast/build/llvm_build_msan/bin/lld+0x57c039)

This reverts commit r345014.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@345017 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Nov 1, 2018
Summary:
As a bonus, this arguably improves the code by making it simpler.

gcc 8 on Ubuntu 18.10 reports the following:

==39667==ERROR: AddressSanitizer: stack-use-after-scope on address 0x7fffffff8ae0 at pc 0x555555dbfc68 bp 0x7fffffff8760 sp 0x7fffffff8750
WRITE of size 8 at 0x7fffffff8ae0 thread T0
    #0 0x555555dbfc67 in std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_Alloc_hider::_Alloc_hider(char*, std::allocator<char>&&) /usr/include/c++/8/bits/basic_string.h:149
    #1 0x555555dbfc67 in std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&&) /usr/include/c++/8/bits/basic_string.h:542
    #2 0x555555dbfc67 in std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > std::operator+<char, std::char_traits<char>, std::allocator<char> >(char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&&) /usr/include/c++/8/bits/basic_string.h:6009
    #3 0x555555dbfc67 in searchableFieldType /home/nha/amd/build/san/llvm-src/utils/TableGen/SearchableTableEmitter.cpp:168
    (...)

Address 0x7fffffff8ae0 is located in stack of thread T0 at offset 864 in frame
    #0 0x555555dbef3f in searchableFieldType /home/nha/amd/build/san/llvm-src/utils/TableGen/SearchableTableEmitter.cpp:148

Reviewers: fhahn, simon_tatham, kparzysz

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D53931

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@345749 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Nov 3, 2018
ModuleSummaryIndex::exportToDot crashes when linking the Linux kernel
under ThinLTO using LLVMgold.so. This is due to the exportToDot
function trying to get the GUID of an empty ValueInfo. The root cause
related to the fact that we attempt to get the GUID of an aliasee
via its OriginalGUID recorded in the aliasee summary, and that is not
always possible. Specifically, we cannot do this mapping when the value
is internal linkage and there were other internal linkage symbols with
the same name.

There are 2 fixes for the problem included here.

1) In all cases where we can currently print the dot file from the
command line (which is only via save-temps), we have a valid AliaseeGUID
in the AliasSummary. Use that when it is available, so that we can get
the correct aliasee GUID whenever possible.

2) However, if we were to invoke exportToDot from the debugger right
after it is built during the initial analysis step (i.e. the per-module
summary), we won't have the AliaseeGUID field populated. In that case,
we have a fallback fix that will simply print "@"+GUID when we aren't
able to get the GUID from the OriginalGUID. It simply checks if the VI
is valid or not before attempting to get the name. Additionally, since
getAliaseeGUID will assert that the AliaseeGUID is non-zero, guard the
earlier fix #1 by a new function hasAliaseeGUID().

Reviewers: pcc, tmroeder

Subscribers: evgeny777, mehdi_amini, inglorion, dexonsmith, arphaman, llvm-commits

Differential Revision: https://reviews.llvm.org/D53986

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@346055 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Nov 13, 2018
Flags variable was not initialized and later used (both isMBBSafeToOutlineFrom
implementations assume it's initialized), which breaks
test/CodeGen/AArch64/machine-outliner.mir. under memory sanitizer:
MemorySanitizer: use-of-uninitialized-value
    #0  in llvm::AArch64InstrInfo::getOutliningType(llvm::MachineInstrBundleIterator<llvm::MachineInstr, false>&, unsigned int) const llvm/lib/Target/AArch64/AArch64InstrInfo.cpp:5494:9
    #1  in (anonymous namespace)::InstructionMapper::convertToUnsignedVec(llvm::MachineBasicBlock&, llvm::TargetInstrInfo const&) llvm/lib/CodeGen/MachineOutliner.cpp:772:19
    #2  in (anonymous namespace)::MachineOutliner::populateMapper((anonymous namespace)::InstructionMapper&, llvm::Module&, llvm::MachineModuleInfo&) llvm/lib/CodeGen/MachineOutliner.cpp:1543:14
    #3  in (anonymous namespace)::MachineOutliner::runOnModule(llvm::Module&) llvm/lib/CodeGen/MachineOutliner.cpp:1645:3
    #4  in (anonymous namespace)::MPPassManager::runOnModule(llvm::Module&) llvm/lib/IR/LegacyPassManager.cpp:1744:27
    #5  in llvm::legacy::PassManagerImpl::run(llvm::Module&) llvm/lib/IR/LegacyPassManager.cpp:1857:44
    #6  in compileModule(char**, llvm::LLVMContext&) llvm/tools/llc/llc.cpp:597:8

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@346761 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Feb 1, 2019
…implify (#1)

This is the second of a series of patches simplifying llvm-symbolizer
tests. See r352752 for the first. This one splits out 5 distinct test
cases from llvm-symbolizer.test into separate tests, and simplifies them
slightly by using --obj/positional arguments for the input file and
addresses instead of stdin.

See https://bugs.llvm.org/show_bug.cgi?id=40070#c1 for the motivation.

Reviewed by: dblaikie

Differential Revision: https://reviews.llvm.org/D57443


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@352753 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Feb 28, 2019
fredriss pushed a commit that referenced this pull request Mar 8, 2019
Introduces memory leak in FunctionTest.GetPointerAlignment that breaks sanitizer buildbots:

```
=================================================================
==2453==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 128 byte(s) in 1 object(s) allocated from:
    #0 0x610428 in operator new(unsigned long) /b/sanitizer-x86_64-linux-bootstrap/build/llvm/projects/compiler-rt/lib/asan/asan_new_delete.cc:105
    #1 0x16936bc in llvm::User::operator new(unsigned long) /b/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/User.cpp:151:19
    #2 0x7c3fe9 in Create /b/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/IR/Function.h:144:12
    #3 0x7c3fe9 in (anonymous namespace)::FunctionTest_GetPointerAlignment_Test::TestBody() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/unittests/IR/FunctionTest.cpp:136
    #4 0x1a836a0 in HandleExceptionsInMethodIfSupported<testing::Test, void> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc
    #5 0x1a836a0 in testing::Test::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2474
    #6 0x1a85c55 in testing::TestInfo::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2656:11
    #7 0x1a870d0 in testing::TestCase::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2774:28
    #8 0x1aa5b84 in testing::internal::UnitTestImpl::RunAllTests() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:4649:43
    #9 0x1aa4d30 in HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc
    #10 0x1aa4d30 in testing::UnitTest::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:4257
    #11 0x1a6b656 in RUN_ALL_TESTS /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/include/gtest/gtest.h:2233:46
    #12 0x1a6b656 in main /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/UnitTestMain/TestMain.cpp:50
    #13 0x7f5af37a22e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)

Indirect leak of 40 byte(s) in 1 object(s) allocated from:
    #0 0x610428 in operator new(unsigned long) /b/sanitizer-x86_64-linux-bootstrap/build/llvm/projects/compiler-rt/lib/asan/asan_new_delete.cc:105
    #1 0x151be6b in make_unique<llvm::ValueSymbolTable> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/ADT/STLExtras.h:1349:29
    #2 0x151be6b in llvm::Function::Function(llvm::FunctionType*, llvm::GlobalValue::LinkageTypes, unsigned int, llvm::Twine const&, llvm::Module*) /b/sanitizer-x86_64-linux-bootstrap/build/llvm/lib/IR/Function.cpp:241
    #3 0x7c4006 in Create /b/sanitizer-x86_64-linux-bootstrap/build/llvm/include/llvm/IR/Function.h:144:16
    #4 0x7c4006 in (anonymous namespace)::FunctionTest_GetPointerAlignment_Test::TestBody() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/unittests/IR/FunctionTest.cpp:136
    #5 0x1a836a0 in HandleExceptionsInMethodIfSupported<testing::Test, void> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc
    #6 0x1a836a0 in testing::Test::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2474
    #7 0x1a85c55 in testing::TestInfo::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2656:11
    #8 0x1a870d0 in testing::TestCase::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:2774:28
    #9 0x1aa5b84 in testing::internal::UnitTestImpl::RunAllTests() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:4649:43
    #10 0x1aa4d30 in HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool> /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc
    #11 0x1aa4d30 in testing::UnitTest::Run() /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/src/gtest.cc:4257
    #12 0x1a6b656 in RUN_ALL_TESTS /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/googletest/include/gtest/gtest.h:2233:46
    #13 0x1a6b656 in main /b/sanitizer-x86_64-linux-bootstrap/build/llvm/utils/unittest/UnitTestMain/TestMain.cpp:50
    #14 0x7f5af37a22e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)

SUMMARY: AddressSanitizer: 168 byte(s) leaked in 2 allocation(s).
```

See http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap/builds/11358/steps/check-llvm%20asan/logs/stdio for more information.

Also introduces use-of-uninitialized-value in ConstantsTest.FoldGlobalVariablePtr:
```
==7070==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x14e703c in User /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/User.h:79:5
    #1 0x14e703c in Constant /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/Constant.h:44
    #2 0x14e703c in llvm::GlobalValue::GlobalValue(llvm::Type*, llvm::Value::ValueTy, llvm::Use*, unsigned int, llvm::GlobalValue::LinkageTypes, llvm::Twine const&, unsigned int) /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/GlobalValue.h:78
    #3 0x14e5467 in GlobalObject /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/GlobalObject.h:34:9
    #4 0x14e5467 in llvm::GlobalVariable::GlobalVariable(llvm::Type*, bool, llvm::GlobalValue::LinkageTypes, llvm::Constant*, llvm::Twine const&, llvm::GlobalValue::ThreadLocalMode, unsigned int, bool) /b/sanitizer-x86_64-linux-fast/build/llvm/lib/IR/Globals.cpp:314
    #5 0x6938f1 in llvm::(anonymous namespace)::ConstantsTest_FoldGlobalVariablePtr_Test::TestBody() /b/sanitizer-x86_64-linux-fast/build/llvm/unittests/IR/ConstantsTest.cpp:565:18
    #6 0x1a240a1 in HandleExceptionsInMethodIfSupported<testing::Test, void> /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc
    #7 0x1a240a1 in testing::Test::Run() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:2474
    #8 0x1a26d26 in testing::TestInfo::Run() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:2656:11
    #9 0x1a2815f in testing::TestCase::Run() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:2774:28
    #10 0x1a43de8 in testing::internal::UnitTestImpl::RunAllTests() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:4649:43
    #11 0x1a42c47 in HandleExceptionsInMethodIfSupported<testing::internal::UnitTestImpl, bool> /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc
    #12 0x1a42c47 in testing::UnitTest::Run() /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/src/gtest.cc:4257
    #13 0x1a0dfba in RUN_ALL_TESTS /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/googletest/include/gtest/gtest.h:2233:46
    #14 0x1a0dfba in main /b/sanitizer-x86_64-linux-fast/build/llvm/utils/unittest/UnitTestMain/TestMain.cpp:50
    #15 0x7f2081c412e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)
    #16 0x4dff49 in _start (/b/sanitizer-x86_64-linux-fast/build/llvm_build_msan/unittests/IR/IRTests+0x4dff49)

SUMMARY: MemorySanitizer: use-of-uninitialized-value /b/sanitizer-x86_64-linux-fast/build/llvm/include/llvm/IR/User.h:79:5 in User
```

See http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/30222/steps/check-llvm%20msan/logs/stdio for more information.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355616 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Mar 22, 2019
Currently, the type id for a derived type is computed incorrectly.
For example,
  type #1: int
  type #2: ptr to #1

For a global variable "int *a", type #1 will be attributed to variable "a".
This is due to a bug which assigns the type id of the basetype of
that derived type as the derived type's type id. This happens
to "const", "volatile", "restrict", "typedef" and "pointer" types.

This patch fixed this bug, fixed existing test cases and added
a new one focusing on pointers plus other derived types.

Signed-off-by: Yonghong Song <yhs@fb.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356727 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Apr 13, 2019
The size field of a location can be different for each entry, so it is useful to have this displayed in the output of llvm-readobj -stackmap. Below is an example of how the output would look:

Record ID: 2882400000, instruction offset: 16
   3 locations:
     #1: Constant 1, size: 8
     #2: Constant 2, size: 8
     #3: Constant 3, size: 8
   0 live-outs: [ ]

Patch By: jacob.hughes@kcl.ac.uk (with heavy modification by me)
Differential Revision: https://reviews.llvm.org/D59169



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358324 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request May 3, 2019
Looks like just a minor oversight in the parsing code.

Fixes https://bugs.llvm.org/show_bug.cgi?id=41504.

Differential Revision: https://reviews.llvm.org/D60840



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359855 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request May 16, 2019
This is the first in a set of patches I have to improve testing of
llvm-objdump. This patch targets --all-headers, --section, and
--full-contents. In the --section case, it deletes a pre-canned binary
which is only used by the one test and replaces it with yaml.

Reviewed by: grimar, MaskRay

Differential Revision: https://reviews.llvm.org/D61941


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360893 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Jun 12, 2019
Looks like a MachinePipeliner algorithm problem found by
sanitizer-x86_64-linux-fast.
I will backout this test first while investigating the problem to
unblock buildbot.

==49637==ERROR: AddressSanitizer: heap-buffer-overflow on address
0x614000002e08 at pc 0x000004364350 bp 0x7ffe228a3bd0 sp 0x7ffe228a3bc8
READ of size 4 at 0x614000002e08 thread T0
    #0 0x436434f in
llvm::SwingSchedulerDAG::checkValidNodeOrder(llvm::SmallVector<llvm::NodeSet,
8u> const&) const
/b/sanitizer-x86_64-linux-fast/build/llvm/lib/CodeGen/MachinePipeliner.cpp:3736:11
    #1 0x4342cd0 in llvm::SwingSchedulerDAG::schedule()
/b/sanitizer-x86_64-linux-fast/build/llvm/lib/CodeGen/MachinePipeliner.cpp:486:3
    #2 0x434042d in
llvm::MachinePipeliner::swingModuloScheduler(llvm::MachineLoop&)
/b/sanitizer-x86_64-linux-fast/build/llvm/lib/CodeGen/MachinePipeliner.cpp:385:7
    #3 0x433eb90 in
llvm::MachinePipeliner::runOnMachineFunction(llvm::MachineFunction&)
/b/sanitizer-x86_64-linux-fast/build/llvm/lib/CodeGen/MachinePipeliner.cpp:207:5
    #4 0x428b7ea in
llvm::MachineFunctionPass::runOnFunction(llvm::Function&)
/b/sanitizer-x86_64-linux-fast/build/llvm/lib/CodeGen/MachineFunctionPass.cpp:73:13
    #5 0x4d1a913 in llvm::FPPassManager::runOnFunction(llvm::Function&)
/b/sanitizer-x86_64-linux-fast/build/llvm/lib/IR/LegacyPassManager.cpp:1648:27
    #6 0x4d1b192 in llvm::FPPassManager::runOnModule(llvm::Module&)
/b/sanitizer-x86_64-linux-fast/build/llvm/lib/IR/LegacyPassManager.cpp:1685:16
    #7 0x4d1c06d in runOnModule
/b/sanitizer-x86_64-linux-fast/build/llvm/lib/IR/LegacyPassManager.cpp:1752:27
    #8 0x4d1c06d in llvm::legacy::PassManagerImpl::run(llvm::Module&)
/b/sanitizer-x86_64-linux-fast/build/llvm/lib/IR/LegacyPassManager.cpp:1865
    #9 0xa48ca3 in compileModule(char**, llvm::LLVMContext&)
/b/sanitizer-x86_64-linux-fast/build/llvm/tools/llc/llc.cpp:611:8
    #10 0xa4270f in main
/b/sanitizer-x86_64-linux-fast/build/llvm/tools/llc/llc.cpp:365:22
    #11 0x7fec902572e0 in __libc_start_main
(/lib/x86_64-linux-gnu/libc.so.6+0x202e0)
    #12 0x971b69 in _start
(/b/sanitizer-x86_64-linux-fast/build/llvm_build_asan/bin/llc+0x971b69)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363105 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Jun 22, 2019
On Windows ARM64, intrinsic __debugbreak is compiled into brk #0xF000 which is
mapped to llvm.debugtrap in Clang. Instruction brk #F000 is the defined break
point instruction on ARM64 which is recognized by Windows debugger and
exception handling code, so llvm.debugtrap should map to it instead of
redirecting to llvm.trap (brk #1) as the default implementation.

Differential Revision: https://reviews.llvm.org/D63635

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364115 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Jul 9, 2019
Introduction
============

This patch added intial support for bpf program compile once
and run everywhere (CO-RE).

The main motivation is for bpf program which depends on
kernel headers which may vary between different kernel versions.
The initial discussion can be found at https://lwn.net/Articles/773198/.

Currently, bpf program accesses kernel internal data structure
through bpf_probe_read() helper. The idea is to capture the
kernel data structure to be accessed through bpf_probe_read()
and relocate them on different kernel versions.

On each host, right before bpf program load, the bpfloader
will look at the types of the native linux through vmlinux BTF,
calculates proper access offset and patch the instruction.

To accommodate this, three intrinsic functions
   preserve_{array,union,struct}_access_index
are introduced which in clang will preserve the base pointer,
struct/union/array access_index and struct/union debuginfo type
information. Later, bpf IR pass can reconstruct the whole gep
access chains without looking at gep itself.

This patch did the following:
  . An IR pass is added to convert preserve_*_access_index to
    global variable who name encodes the getelementptr
    access pattern. The global variable has metadata
    attached to describe the corresponding struct/union
    debuginfo type.
  . An SimplifyPatchable MachineInstruction pass is added
    to remove unnecessary loads.
  . The BTF output pass is enhanced to generate relocation
    records located in .BTF.ext section.

Typical CO-RE also needs support of global variables which can
be assigned to different values to different hosts. For example,
kernel version can be used to guard different versions of codes.
This patch added the support for patchable externals as well.

Example
=======

The following is an example.

  struct pt_regs {
    long arg1;
    long arg2;
  };
  struct sk_buff {
    int i;
    struct net_device *dev;
  };

  #define _(x) (__builtin_preserve_access_index(x))
  static int (*bpf_probe_read)(void *dst, int size, const void *unsafe_ptr) =
          (void *) 4;
  extern __attribute__((section(".BPF.patchable_externs"))) unsigned __kernel_version;
  int bpf_prog(struct pt_regs *ctx) {
    struct net_device *dev = 0;

    // ctx->arg* does not need bpf_probe_read
    if (__kernel_version >= 41608)
      bpf_probe_read(&dev, sizeof(dev), _(&((struct sk_buff *)ctx->arg1)->dev));
    else
      bpf_probe_read(&dev, sizeof(dev), _(&((struct sk_buff *)ctx->arg2)->dev));
    return dev != 0;
  }

In the above, we want to translate the third argument of
bpf_probe_read() as relocations.

  -bash-4.4$ clang -target bpf -O2 -g -S trace.c

The compiler will generate two new subsections in .BTF.ext,
OffsetReloc and ExternReloc.
OffsetReloc is to record the structure member offset operations,
and ExternalReloc is to record the external globals where
only u8, u16, u32 and u64 are supported.

   BPFOffsetReloc Size
   struct SecLOffsetReloc for ELF section #1
   A number of struct BPFOffsetReloc for ELF section #1
   struct SecOffsetReloc for ELF section #2
   A number of struct BPFOffsetReloc for ELF section #2
   ...
   BPFExternReloc Size
   struct SecExternReloc for ELF section #1
   A number of struct BPFExternReloc for ELF section #1
   struct SecExternReloc for ELF section #2
   A number of struct BPFExternReloc for ELF section #2

  struct BPFOffsetReloc {
    uint32_t InsnOffset;    ///< Byte offset in this section
    uint32_t TypeID;        ///< TypeID for the relocation
    uint32_t OffsetNameOff; ///< The string to traverse types
  };

  struct BPFExternReloc {
    uint32_t InsnOffset;    ///< Byte offset in this section
    uint32_t ExternNameOff; ///< The string for external variable
  };

Note that only externs with attribute section ".BPF.patchable_externs"
are considered for Extern Reloc which will be patched by bpf loader
right before the load.

For the above test case, two offset records and one extern record
will be generated:
  OffsetReloc records:
        .long   .Ltmp12                 # Insn Offset
        .long   7                       # TypeId
        .long   242                     # Type Decode String
        .long   .Ltmp18                 # Insn Offset
        .long   7                       # TypeId
        .long   242                     # Type Decode String

  ExternReloc record:
        .long   .Ltmp5                  # Insn Offset
        .long   165                     # External Variable

  In string table:
        .ascii  "0:1"                   # string offset=242
        .ascii  "__kernel_version"      # string offset=165

The default member offset can be calculated as
    the 2nd member offset (0 representing the 1st member) of struct "sk_buff".

The asm code:
    .Ltmp5:
    .Ltmp6:
            r2 = 0
            r3 = 41608
    .Ltmp7:
    .Ltmp8:
            .loc    1 18 9 is_stmt 0        # t.c:18:9
    .Ltmp9:
            if r3 > r2 goto LBB0_2
    .Ltmp10:
    .Ltmp11:
            .loc    1 0 9                   # t.c:0:9
    .Ltmp12:
            r2 = 8
    .Ltmp13:
            .loc    1 19 66 is_stmt 1       # t.c:19:66
    .Ltmp14:
    .Ltmp15:
            r3 = *(u64 *)(r1 + 0)
            goto LBB0_3
    .Ltmp16:
    .Ltmp17:
    LBB0_2:
            .loc    1 0 66 is_stmt 0        # t.c:0:66
    .Ltmp18:
            r2 = 8
            .loc    1 21 66 is_stmt 1       # t.c:21:66
    .Ltmp19:
            r3 = *(u64 *)(r1 + 8)
    .Ltmp20:
    .Ltmp21:
    LBB0_3:
            .loc    1 0 66 is_stmt 0        # t.c:0:66
            r3 += r2
            r1 = r10
    .Ltmp22:
    .Ltmp23:
    .Ltmp24:
            r1 += -8
            r2 = 8
            call 4

For instruction .Ltmp12 and .Ltmp18, "r2 = 8", the number
8 is the structure offset based on the current BTF.
Loader needs to adjust it if it changes on the host.

For instruction .Ltmp5, "r2 = 0", the external variable
got a default value 0, loader needs to supply an appropriate
value for the particular host.

Compiling to generate object code and disassemble:
   0000000000000000 bpf_prog:
           0:       b7 02 00 00 00 00 00 00         r2 = 0
           1:       7b 2a f8 ff 00 00 00 00         *(u64 *)(r10 - 8) = r2
           2:       b7 02 00 00 00 00 00 00         r2 = 0
           3:       b7 03 00 00 88 a2 00 00         r3 = 41608
           4:       2d 23 03 00 00 00 00 00         if r3 > r2 goto +3 <LBB0_2>
           5:       b7 02 00 00 08 00 00 00         r2 = 8
           6:       79 13 00 00 00 00 00 00         r3 = *(u64 *)(r1 + 0)
           7:       05 00 02 00 00 00 00 00         goto +2 <LBB0_3>

    0000000000000040 LBB0_2:
           8:       b7 02 00 00 08 00 00 00         r2 = 8
           9:       79 13 08 00 00 00 00 00         r3 = *(u64 *)(r1 + 8)

    0000000000000050 LBB0_3:
          10:       0f 23 00 00 00 00 00 00         r3 += r2
          11:       bf a1 00 00 00 00 00 00         r1 = r10
          12:       07 01 00 00 f8 ff ff ff         r1 += -8
          13:       b7 02 00 00 08 00 00 00         r2 = 8
          14:       85 00 00 00 04 00 00 00         call 4

Instructions #2, #5 and #8 need relocation resoutions from the loader.

Signed-off-by: Yonghong Song <yhs@fb.com>

Differential Revision: https://reviews.llvm.org/D61524

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365503 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Jul 25, 2019
Summary:
Every time PrettyPrinter::printInst is called, stdout is flushed and it makes llvm-objdump slow. This patches adds a string
buffer to prevent stdout from being flushed.

Benchmark results (./llvm-objdump-master: without this patch,  ./bin/llvm-objcopy: with this patch):

  $ hyperfine --warmup 10 './llvm-objdump-master -d ./bin/llvm-objcopy' './bin/llvm-objdump -d ./bin/llvm-objcopy'
  Benchmark #1: ./llvm-objdump-master -d ./bin/llvm-objcopy
    Time (mean ± σ):      2.230 s ±  0.050 s    [User: 1.533 s, System: 0.682 s]
    Range (min … max):    2.115 s …  2.278 s    10 runs

  Benchmark #2: ./bin/llvm-objdump -d ./bin/llvm-objcopy
    Time (mean ± σ):     386.4 ms ±  13.0 ms    [User: 376.6 ms, System: 6.1 ms]
    Range (min … max):   366.1 ms … 407.0 ms    10 runs

  Summary
    './bin/llvm-objdump -d ./bin/llvm-objcopy' ran
      5.77 ± 0.23 times faster than './llvm-objdump-master -d ./bin/llvm-objcopy'

Reviewers: alexshap, Bigcheese, jhenderson, rupprecht, grimar, MaskRay

Reviewed By: jhenderson, MaskRay

Subscribers: dexonsmith, jhenderson, javed.absar, kristof.beyls, rupprecht, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64969

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366984 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Aug 13, 2019
Summary:
int mm(char *a, char *b) {
    return memcmp(a,b,16);
}

Currently:
define dso_local i32 @mm(i8* nocapture readonly %a, i8* nocapture readonly %b) local_unnamed_addr #1 {
entry:
  %call = tail call i32 @memcmp(i8* %a, i8* %b, i64 16)
  ret i32 %call
}

After patch:
define dso_local i32 @mm(i8* nocapture readonly %a, i8* nocapture readonly %b) local_unnamed_addr #1 {
entry:
  %call = tail call i32 @memcmp(i8* dereferenceable(16)  %a, i8* dereferenceable(16)  %b, i64 16)
  ret i32 %call
}




Reviewers: jdoerfert, efriedma

Reviewed By: jdoerfert

Subscribers: javed.absar, spatel, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66079

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@368657 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Aug 17, 2019
Summary:
Before we required the comparison against null to be "canonical", hence
null to be operand #1. This patch allows null to be in either operand,
similar to the handling of loaded globals that follows.

Reviewers: sanjoy, hfinkel, aykevl, sstefan1, uenoku

Subscribers: hiraditya, bollu, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66321

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@369158 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Sep 3, 2019
…ymbol that belongs to a section with a broken sh_name"

It broke BB:
http://lab.llvm.org:8011/builders/clang-x86_64-debian-fast/builds/16955/steps/test/logs/stdio

Expected<T> must be checked before access or destruction.
Unchecked Expected<T> contained error:
a section [index 1] has an invalid sh_name (0xffff) offset which goes past the end of the section name string tableStack dump:
0.	Program arguments: /srv/llvm-buildbot-srcatch/llvm-build-dir/clang-x86_64-debian-fast/llvm.obj/bin/llvm-nm /srv/llvm-buildbot-srcatch/llvm-build-dir/clang-x86_64-debian-fast/llvm.obj/test/tools/llvm-nm/Output/format-sysv-section.test.tmp2.o --format=sysv 
 #0 0x00000000008af7c4 PrintStackTraceSignalHandler(void*) (/srv/llvm-buildbot-srcatch/llvm-build-dir/clang-x86_64-debian-fast/llvm.obj/bin/llvm-nm+0x8af7c4)
 #1 0x00000000008ad8be llvm::sys::RunSignalHandlers() (/srv/llvm-buildbot-srcatch/llvm-build-dir/clang-x86_64-debian-fast/llvm.obj/bin/llvm-nm+0x8ad8be)
 #2 0x00000000008afbd8 SignalHandler(int) (/srv/llvm-buildbot-srcatch/llvm-build-dir/clang-x86_64-debian-fast/llvm.obj/bin/llvm-nm+0x8afbd8)
 #3 0x00007f0a6b989730 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x12730)
 #4 0x00007f0a6b48d7bb raise (/lib/x86_64-linux-gnu/libc.so.6+0x377bb)
 #5 0x00007f0a6b478535 abort (/lib/x86_64-linux-gnu/libc.so.6+0x22535)
 #6 0x000000000042004b llvm::Expected<llvm::StringRef>::fatalUncheckedExpected() const (/srv/llvm-buildbot-srcatch/llvm-build-dir/clang-x86_64-debian-fast/llvm.obj/bin/llvm-nm+0x42004b)
 #7 0x00000000008367f5 (/sv/llvm-buildbot-srcatch/llvm-build-dir/clang-x86_64-debian-fast/llvm.obj/bin/llvm-nm+0x8367f5)
 #8 0x0000000000817b80 llvm::object::IRObjectFile::findBitcodeInObject(llvm::object::ObjectFile const&) (/srv/llvm-buildbot-srcatch/llvm-build-dir/clang-x86_64-debian-fast/llvm.obj/bin/llvm-nm+0x817b80)
 #9 0x0000000000838416 llvm::object::SymbolicFile::createSymbolicFile(llvm::MemoryBufferRef, llvm::file_magic, llvm::LLVMContext*) (/srv/llvm-buildbot-srcatch/llvm-build-dir/clang-x86_64-debian-fast/llvm.obj/bin/llvm-nm+0x838416)
#10 0x00000000007f36cb llvm::object::createBinary(llvm::MemoryBufferRef, llvm::LLVMContext*) (/srv/llvm-buildbot-srcatch/llvm-build-dir/clang-x86_64-debian-fast/llvm.obj/bin/llvm-nm+0x7f36cb)
#11 0x0000000000413123 dumpSymbolNamesFromFile(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&) (/srv/llvm-buildbot-srcatch/llvm-build-dir/clang-x86_64-debian-fast/llvm.obj/bin/llvm-nm+0x413123)
#12 0x0000000000412e38 main (/srv/llvm-buildbot-srcatch/llvm-build-dir/clang-x86_64-debian-fast/llvm.obj/bin/llvm-nm+0x412e38)
#13 0x00007f0a6b47a09b __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409b)
#14 0x00000000004120da _start (/srv/llvm-buildbot-srcatch/llvm-build-dir/clang-x86_64-debian-fast/llvm.obj/bin/llvm-nm+0x4120da)
FileCheck error: '-' is empty.
FileCheck command line:  /srv/llvm-buildbot-srcatch/llvm-build-dir/clang-x86_64-debian-fast/llvm.obj/bin/FileCheck /srv/llvm-buildbot-srcatch/llvm-build-dir/clang-x86_64-debian-fast/llvm.src/test/tools/llvm-nm/format-sysv-section.test --check-prefix=ERR

--

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@370662 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Sep 19, 2019
Summary:
This reverts commit r372204.

This change causes build bot failures under msan:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/35236/steps/check-llvm%20msan/logs/stdio:

```
FAIL: LLVM :: DebugInfo/AArch64/asan-stack-vars.mir (19531 of 33579)
******************** TEST 'LLVM :: DebugInfo/AArch64/asan-stack-vars.mir' FAILED ********************
Script:
--
: 'RUN: at line 1';   /b/sanitizer-x86_64-linux-fast/build/llvm_build_msan/bin/llc -O0 -start-before=livedebugvalues -filetype=obj -o - /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/test/DebugInfo/AArch64/asan-stack-vars.mir | /b/sanitizer-x86_64-linux-fast/build/llvm_build_msan/bin/llvm-dwarfdump -v - | /b/sanitizer-x86_64-linux-fast/build/llvm_build_msan/bin/FileCheck /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/test/DebugInfo/AArch64/asan-stack-vars.mir
--
Exit Code: 2

Command Output (stderr):
--
==62894==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0xdfcafb in llvm::AArch64FrameLowering::resolveFrameOffsetReference(llvm::MachineFunction const&, int, bool, unsigned int&, bool, bool) const /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp:1658:3
    #1 0xdfae8a in resolveFrameIndexReference /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp:1580:10
    #2 0xdfae8a in llvm::AArch64FrameLowering::getFrameIndexReference(llvm::MachineFunction const&, int, unsigned int&) const /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp:1536
    #3 0x46642c1 in (anonymous namespace)::LiveDebugValues::extractSpillBaseRegAndOffset(llvm::MachineInstr const&) /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/CodeGen/LiveDebugValues.cpp:582:21
    #4 0x4647cb3 in transferSpillOrRestoreInst /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/CodeGen/LiveDebugValues.cpp:883:11
    #5 0x4647cb3 in process /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/CodeGen/LiveDebugValues.cpp:1079
    #6 0x4647cb3 in (anonymous namespace)::LiveDebugValues::ExtendRanges(llvm::MachineFunction&) /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/CodeGen/LiveDebugValues.cpp:1361
    #7 0x463ac0e in (anonymous namespace)::LiveDebugValues::runOnMachineFunction(llvm::MachineFunction&) /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/CodeGen/LiveDebugValues.cpp:1415:18
    #8 0x4854ef0 in llvm::MachineFunctionPass::runOnFunction(llvm::Function&) /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/CodeGen/MachineFunctionPass.cpp:73:13
    #9 0x53b0b01 in llvm::FPPassManager::runOnFunction(llvm::Function&) /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:1648:27
    #10 0x53b15f6 in llvm::FPPassManager::runOnModule(llvm::Module&) /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:1685:16
    #11 0x53b298d in runOnModule /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:1750:27
    #12 0x53b298d in llvm::legacy::PassManagerImpl::run(llvm::Module&) /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/IR/LegacyPassManager.cpp:1863
    #13 0x905f21 in compileModule(char**, llvm::LLVMContext&) /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/tools/llc/llc.cpp:601:8
    #14 0x8fdc4e in main /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/tools/llc/llc.cpp:355:22
    #15 0x7f67673632e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)
    #16 0x882369 in _start (/b/sanitizer-x86_64-linux-fast/build/llvm_build_msan/bin/llc+0x882369)

MemorySanitizer: use-of-uninitialized-value /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/Target/AArch64/AArch64FrameLowering.cpp:1658:3 in llvm::AArch64FrameLowering::resolveFrameOffsetReference(llvm::MachineFunction const&, int, bool, unsigned int&, bool, bool) const
Exiting
error: -: The file was not recognized as a valid object file
FileCheck error: '-' is empty.
FileCheck command line:  /b/sanitizer-x86_64-linux-fast/build/llvm_build_msan/bin/FileCheck /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/test/DebugInfo/AArch64/asan-stack-vars.mir
```

Reviewers: bkramer

Reviewed By: bkramer

Subscribers: sdardis, aprantl, kristof.beyls, jrtc27, atanasyan, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67710

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@372228 91177308-0d34-0410-b5e6-96231b3b80d8
fredriss pushed a commit that referenced this pull request Oct 11, 2019
This test is not defined.

FAIL: LLVM-Unit :: ADT/./ADTTests/ArrayRefTest.SizeTSizedOperations (178 of 33926)
******************** TEST 'LLVM-Unit :: ADT/./ADTTests/ArrayRefTest.SizeTSizedOperations' FAILED ********************
Note: Google Test filter = ArrayRefTest.SizeTSizedOperations
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from ArrayRefTest
[ RUN      ] ArrayRefTest.SizeTSizedOperations
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/include/llvm/ADT/ArrayRef.h:180:32: runtime error: applying non-zero offset 9223372036854775806 to null pointer
    #0 0x5ae8dc in llvm::ArrayRef<char>::slice(unsigned long, unsigned long) const /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/include/llvm/ADT/ArrayRef.h:180:32
    #1 0x5ae44c in (anonymous namespace)::ArrayRefTest_SizeTSizedOperations_Test::TestBody() /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/unittests/ADT/ArrayRefTest.cpp:85:3
    #2 0x928a96 in testing::Test::Run() /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/utils/unittest/googletest/src/gtest.cc:2474:5
    #3 0x929793 in testing::TestInfo::Run() /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/utils/unittest/googletest/src/gtest.cc:2656:11
    #4 0x92a152 in testing::TestCase::Run() /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/utils/unittest/googletest/src/gtest.cc:2774:28
    #5 0x9319d2 in testing::internal::UnitTestImpl::RunAllTests() /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/utils/unittest/googletest/src/gtest.cc:4649:43
    #6 0x931416 in testing::UnitTest::Run() /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/utils/unittest/googletest/src/gtest.cc:4257:10
    #7 0x920ac3 in RUN_ALL_TESTS /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/utils/unittest/googletest/include/gtest/gtest.h:2233:46
    #8 0x920ac3 in main /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/utils/unittest/UnitTestMain/TestMain.cpp:50:10
    #9 0x7f66135b72e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)
    #10 0x472c19 in _start (/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/unittests/ADT/ADTTests+0x472c19)

SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/include/llvm/ADT/ArrayRef.h:180:32 in

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@374327 91177308-0d34-0410-b5e6-96231b3b80d8
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