Skip to content

AMD OpenCL 1.2 adapter pass #1

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Sep 9, 2016

Conversation

nhaustov
Copy link

@nhaustov nhaustov commented Sep 8, 2016

Handles 1.2 builtin calls and create wrapper functions that call 2.0 counterpart inside.

Handles 1.2 builtin calls and create wrapper functions that call 2.0 counterpart inside.
@nhaustov nhaustov merged commit ca8314b into ROCm:amd-common Sep 9, 2016
@nhaustov nhaustov mentioned this pull request Sep 9, 2016
tstellarAMD 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
tstellarAMD 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
tstellarAMD 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
tstellarAMD 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
tstellarAMD 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
tstellarAMD pushed a commit that referenced this pull request Dec 14, 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
tstellarAMD 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
tstellarAMD 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
kzhuravl 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
whchung added a commit that referenced this pull request Mar 16, 2017
…ge (#1)

* Additional patches for AMDGPU backend to cope with new address space mapping

Contributed by Gregory Rodgers

* Fix AMDGPU address space mapping

Conflicts:
	lib/Target/AMDGPU/AMDGPU.h
kzhuravl pushed a commit that referenced this pull request Mar 24, 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
whchung added a commit that referenced this pull request Mar 31, 2017
…ge (#1)

* Additional patches for AMDGPU backend to cope with new address space mapping

Contributed by Gregory Rodgers

* Fix AMDGPU address space mapping

Conflicts:
	lib/Target/AMDGPU/AMDGPU.h

Conflicts:
	lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
kzhuravl 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
kzhuravl 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
kzhuravl pushed a commit that referenced this pull request May 29, 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
kzhuravl 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
kzhuravl 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
kzhuravl 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
kzhuravl pushed a commit that referenced this pull request Oct 22, 2017
This fixes bugzilla 26810
https://bugs.llvm.org/show_bug.cgi?id=26810

This is intended to prevent sequences like:
movl %ebp, 8(%esp) # 4-byte Spill
movl %ecx, %ebp
movl %ebx, %ecx
movl %edi, %ebx
movl %edx, %edi
cltd
idivl %esi
movl %edi, %edx
movl %ebx, %edi
movl %ecx, %ebx
movl %ebp, %ecx
movl 16(%esp), %ebp # 4 - byte Reload

Such sequences are created in 2 scenarios:

Scenario #1:
vreg0 is evicted from physreg0 by vreg1
Evictee vreg0 is intended for region splitting with split candidate physreg0 (the reg vreg0 was evicted from)
Region splitting creates a local interval because of interference with the evictor vreg1 (normally region spliiting creates 2 interval, the "by reg" and "by stack" intervals. Local interval created when interference occurs.)
one of the split intervals ends up evicting vreg2 from physreg1
Evictee vreg2 is intended for region splitting with split candidate physreg1
one of the split intervals ends up evicting vreg3 from physreg2 etc.. until someone spills

Scenario #2
vreg0 is evicted from physreg0 by vreg1
vreg2 is evicted from physreg2 by vreg3 etc
Evictee vreg0 is intended for region splitting with split candidate physreg1
Region splitting creates a local interval because of interference with the evictor vreg1
one of the split intervals ends up evicting back original evictor vreg1 from physreg0 (the reg vreg0 was evicted from)
Another evictee vreg2 is intended for region splitting with split candidate physreg1
one of the split intervals ends up evicting vreg3 from physreg2 etc.. until someone spills

As compile time was a concern, I've added a flag to control weather we do cost calculations for local intervals we expect to be created (it's on by default for X86 target, off for the rest).

Differential Revision: https://reviews.llvm.org/D35816

Change-Id: Id9411ff7bbb845463d289ba2ae97737a1ee7cc39

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316295 91177308-0d34-0410-b5e6-96231b3b80d8
kzhuravl pushed a commit that referenced this pull request Oct 27, 2017
Summary:
The code comments indicate that no effort has been spent on
handling load/stores when the size isn't a multiple of the
byte size correctly. However, the code only avoided types
smaller than 8 bits. So for example a load of an i28 could
still be considered as a candidate for vectorization.

This patch adjusts the code to behave according to the code
comment.

The test case used to hit the following assert when
trying to use "cast" an i32 to i28 using CreateBitOrPointerCast:

opt: ../lib/IR/Instructions.cpp:2565: Assertion `castIsValid(op, S, Ty) && "Invalid cast!"' failed.
#0 PrintStackTraceSignalHandler(void*)
#1 SignalHandler(int)
#2 __restore_rt
#3 __GI_raise
#4 __GI_abort
#5 __GI___assert_fail
#6 llvm::CastInst::Create(llvm::Instruction::CastOps, llvm::Value*, llvm::Type*, llvm::Twine const&, llvm::Instruction*)
#7 llvm::IRBuilder<llvm::ConstantFolder, llvm::IRBuilderDefaultInserter>::CreateBitOrPointerCast(llvm::Value*, llvm::Type*, llvm::Twine const&)
#8 (anonymous namespace)::Vectorizer::vectorizeLoadChain(llvm::ArrayRef<llvm::Instruction*>, llvm::SmallPtrSet<llvm::Instruction*, 16u>*)

Reviewers: arsenm

Reviewed By: arsenm

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D39295

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316663 91177308-0d34-0410-b5e6-96231b3b80d8
kzhuravl pushed a commit that referenced this pull request Oct 27, 2017
Summary:
We no longer add vectors of pointers as candidates for
load/store vectorization. It does not seem to work anyway,
but without this patch we can end up in asserts when trying
to create casts between an integer type and the pointer of
vectors type.

The test case I've added used to assert like this when trying to
cast between i64 and <2 x i16*>:
opt: ../lib/IR/Instructions.cpp:2565: Assertion `castIsValid(op, S, Ty) && "Invalid cast!"' failed.
#0 PrintStackTraceSignalHandler(void*)
#1 SignalHandler(int)
#2 __restore_rt
#3 __GI_raise
#4 __GI_abort
#5 __GI___assert_fail
#6 llvm::CastInst::Create(llvm::Instruction::CastOps, llvm::Value*, llvm::Type*, llvm::Twine const&, llvm::Instruction*)
#7 llvm::IRBuilder<llvm::ConstantFolder, llvm::IRBuilderDefaultInserter>::CreateBitOrPointerCast(llvm::Value*, llvm::Type*, llvm::Twine const&)
#8 Vectorizer::vectorizeStoreChain(llvm::ArrayRef<llvm::Instruction*>, llvm::SmallPtrSet<llvm::Instruction*, 16u>*)

Reviewers: arsenm

Reviewed By: arsenm

Subscribers: nhaehnle, llvm-commits

Differential Revision: https://reviews.llvm.org/D39296

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316665 91177308-0d34-0410-b5e6-96231b3b80d8
kzhuravl pushed a commit that referenced this pull request Oct 30, 2017
…in IPSCCP.

This version of the patch includes a fix addressing a stage2 LTO buildbot
failure and addressed some additional nits.

Original commit message:
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@316887 91177308-0d34-0410-b5e6-96231b3b80d8
kzhuravl pushed a commit that referenced this pull request Oct 30, 2017
…in IPSCCP.

This version of the patch includes a fix addressing a stage2 LTO buildbot
failure and addressed some additional nits.

Original commit message:
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@316891 91177308-0d34-0410-b5e6-96231b3b80d8
kzhuravl pushed a commit that referenced this pull request Dec 17, 2017
We want to do this for 2 reasons:
1. Value tracking does not recognize the ashr variant, so it would fail to match for cases like D39766.
2. DAGCombiner does better at producing optimal codegen when we have the cmp+sel pattern.

More detail about what happens in the backend:
1. DAGCombiner has a generic transform for all targets to convert the scalar cmp+sel variant of abs 
   into the shift variant. That is the opposite of this IR canonicalization.
2. DAGCombiner has a generic transform for all targets to convert the vector cmp+sel variant of abs 
   into either an ABS node or the shift variant. That is again the opposite of this IR canonicalization.
3. DAGCombiner has a generic transform for all targets to convert the exact shift variants produced by #1 or #2
   into an ISD::ABS node. Note: It would be an efficiency improvement if we had #1 go directly to an ABS node 
   when that's legal/custom.
4. The pattern matching above is incomplete, so it is possible to escape the intended/optimal codegen in a 
   variety of ways.
   a. For #2, the vector path is missing the case for setlt with a '1' constant.
   b. For #3, we are missing a match for commuted versions of the shift variants.
5. Therefore, this IR canonicalization can only help get us to the optimal codegen. The version of cmp+sel 
   produced by this patch will be recognized in the DAG and converted to an ABS node when possible or the 
   shift sequence when not.
6. In the following examples with this patch applied, we may get conditional moves rather than the shift 
   produced by the generic DAGCombiner transforms. The conditional move is created using a target-specific 
   decision for any given target. Whether it is optimal or not for a particular subtarget may be up for debate.

define i32 @abs_shifty(i32 %x) {
  %signbit = ashr i32 %x, 31 
  %add = add i32 %signbit, %x  
  %abs = xor i32 %signbit, %add 
  ret i32 %abs
}

define i32 @abs_cmpsubsel(i32 %x) {
  %cmp = icmp slt i32 %x, zeroinitializer
  %sub = sub i32 zeroinitializer, %x
  %abs = select i1 %cmp, i32 %sub, i32 %x
  ret i32 %abs
}

define <4 x i32> @abs_shifty_vec(<4 x i32> %x) {
  %signbit = ashr <4 x i32> %x, <i32 31, i32 31, i32 31, i32 31> 
  %add = add <4 x i32> %signbit, %x  
  %abs = xor <4 x i32> %signbit, %add 
  ret <4 x i32> %abs
}

define <4 x i32> @abs_cmpsubsel_vec(<4 x i32> %x) {
  %cmp = icmp slt <4 x i32> %x, zeroinitializer
  %sub = sub <4 x i32> zeroinitializer, %x
  %abs = select <4 x i1> %cmp, <4 x i32> %sub, <4 x i32> %x
  ret <4 x i32> %abs
}

> $ ./opt -instcombine shiftyabs.ll -S | ./llc -o - -mtriple=x86_64 -mattr=avx 
> abs_shifty:
> 	movl	%edi, %eax
> 	negl	%eax
> 	cmovll	%edi, %eax
> 	retq
> 
> abs_cmpsubsel:
> 	movl	%edi, %eax
> 	negl	%eax
> 	cmovll	%edi, %eax
> 	retq
> 
> abs_shifty_vec:
> 	vpabsd	%xmm0, %xmm0
> 	retq
> 
> abs_cmpsubsel_vec:
> 	vpabsd	%xmm0, %xmm0
> 	retq
> 
> $ ./opt -instcombine shiftyabs.ll -S | ./llc -o - -mtriple=aarch64
> abs_shifty:
> 	cmp	w0, #0                  // =0
> 	cneg	w0, w0, mi
> 	ret
> 
> abs_cmpsubsel: 
> 	cmp	w0, #0                  // =0
> 	cneg	w0, w0, mi
> 	ret
>                                        
> abs_shifty_vec: 
> 	abs	v0.4s, v0.4s
> 	ret
> 
> abs_cmpsubsel_vec: 
> 	abs	v0.4s, v0.4s
> 	ret
> 
> $ ./opt -instcombine shiftyabs.ll -S | ./llc -o - -mtriple=powerpc64le 
> abs_shifty:  
> 	srawi 4, 3, 31
> 	add 3, 3, 4
> 	xor 3, 3, 4
> 	blr
> 
> abs_cmpsubsel:
> 	srawi 4, 3, 31
> 	add 3, 3, 4
> 	xor 3, 3, 4
> 	blr
> 
> abs_shifty_vec:   
> 	vspltisw 3, -16
> 	vspltisw 4, 15
> 	vsubuwm 3, 4, 3
> 	vsraw 3, 2, 3
> 	vadduwm 2, 2, 3
> 	xxlxor 34, 34, 35
> 	blr
> 
> abs_cmpsubsel_vec: 
> 	vspltisw 3, -16
> 	vspltisw 4, 15
> 	vsubuwm 3, 4, 3
> 	vsraw 3, 2, 3
> 	vadduwm 2, 2, 3
> 	xxlxor 34, 34, 35
> 	blr
>

Differential Revision: https://reviews.llvm.org/D40984





git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320921 91177308-0d34-0410-b5e6-96231b3b80d8
kzhuravl pushed a commit that referenced this pull request Dec 29, 2017
Summary:
I have been getting rather difficult to reproduce SIGBUS crashes when
compiling certain FreeBSD sources, and their stack traces pointed
squarely at `SelectionDAG::salvageDebugInfo()`:

```
Core was generated by `/usr/obj/share/dim/src/freebsd/clang600-import/amd64.amd64/tmp/usr/bin/cc -cc1 -'.
Program terminated with signal SIGBUS, Bus error.
#0  isInvalidated () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/CodeGen/SelectionDAG/SDNodeDbgValue.h:115
115       bool isInvalidated() const { return Invalid; }
(gdb) bt
#0  isInvalidated () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/CodeGen/SelectionDAG/SDNodeDbgValue.h:115
#1  salvageDebugInfo () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:7116
#2  0x00000000033b2516 in operator() () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:3595
#3  __invoke<(lambda at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:3593:59) &, llvm::SDNode *, llvm::SDNode *> () at /usr/include/c++/v1/type_traits:4323
#4  __call<(lambda at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:3593:59) &, llvm::SDNode *, llvm::SDNode *> () at /usr/include/c++/v1/__functional_base:349
#5  operator() () at /usr/include/c++/v1/functional:1562
#6  0x00000000033b0817 in operator() () at /usr/include/c++/v1/functional:1916
#7  NodeDeleted () at /share/dim/src/freebsd/clang600-import/contrib/llvm/include/llvm/CodeGen/SelectionDAG.h:293
#8  0x0000000003529dde in RemoveDeadNodes () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:610
#9  0x00000000035556df in MorphNodeTo () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:6794
#10 0x00000000033a9acc in MorphNode () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:2594
#11 0x00000000033ac80b in SelectCodeCommon () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:3601
#12 0x00000000023d464b in SelectCode () at /usr/obj/share/dim/src/freebsd/clang600-import/amd64.amd64/tmp/obj-tools/lib/clang/libllvm/X86GenDAGISel.inc:282902
#13 Select () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp:3072
#14 0x00000000033a5afa in DoInstructionSelection () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:988
#15 0x00000000033a4e1a in CodeGenAndEmitDAG () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:868
#16 0x00000000033a2643 in SelectAllBasicBlocks () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:1624
#17 0x000000000339f158 in runOnMachineFunction () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:466
#18 0x00000000023d03c4 in runOnMachineFunction () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp:175
#19 0x00000000035cc8c2 in runOnFunction () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/CodeGen/MachineFunctionPass.cpp:62
#20 0x00000000030dca9a in runOnFunction () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/IR/LegacyPassManager.cpp:1520
#21 0x00000000030dccf3 in runOnModule () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/IR/LegacyPassManager.cpp:1541
#22 0x00000000030dd228 in runOnModule () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/IR/LegacyPassManager.cpp:1597
#23 run () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/IR/LegacyPassManager.cpp:1700
#24 0x00000000014db578 in EmitAssembly () at /share/dim/src/freebsd/clang600-import/contrib/llvm/tools/clang/lib/CodeGen/BackendUtil.cpp:815
#25 EmitBackendOutput () at /share/dim/src/freebsd/clang600-import/contrib/llvm/tools/clang/lib/CodeGen/BackendUtil.cpp:1181
#26 0x00000000014d5b26 in HandleTranslationUnit () at /share/dim/src/freebsd/clang600-import/contrib/llvm/tools/clang/lib/CodeGen/CodeGenAction.cpp:292
#27 0x0000000001c4c332 in ParseAST () at /share/dim/src/freebsd/clang600-import/contrib/llvm/tools/clang/lib/Parse/ParseAST.cpp:159
#28 0x00000000015d546c in Execute () at /share/dim/src/freebsd/clang600-import/contrib/llvm/tools/clang/lib/Frontend/FrontendAction.cpp:897
#29 0x0000000001cec311 in ExecuteAction () at /share/dim/src/freebsd/clang600-import/contrib/llvm/tools/clang/lib/Frontend/CompilerInstance.cpp:991
#30 0x00000000014b4f81 in ExecuteCompilerInvocation () at /share/dim/src/freebsd/clang600-import/contrib/llvm/tools/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp:252
#31 0x00000000014aa73f in cc1_main () at /share/dim/src/freebsd/clang600-import/contrib/llvm/tools/clang/tools/driver/cc1_main.cpp:221
#32 0x00000000014b2928 in ExecuteCC1Tool () at /share/dim/src/freebsd/clang600-import/contrib/llvm/tools/clang/tools/driver/driver.cpp:309
#33 main () at /share/dim/src/freebsd/clang600-import/contrib/llvm/tools/clang/tools/driver/driver.cpp:388
(gdb) frame 1
#1  salvageDebugInfo () at /share/dim/src/freebsd/clang600-import/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:7116
7116        if (DV->isInvalidated())
(gdb) disassemble
Dump of assembler code for function salvageDebugInfo():
[...]
   0x0000000003557348 <+744>:   nopl   0x0(%rax,%rax,1)
   0x0000000003557350 <+752>:   mov    (%r12),%r13
=> 0x0000000003557354 <+756>:   cmpb   $0x0,0x31(%r13)
   0x0000000003557359 <+761>:   jne    0x35573b0 <salvageDebugInfo()+848>
(gdb) info registers
[...]
r13            0x5a5a5a5a5a5a5a5a       6510615555426900570
```

The `0x5a5a5a5a5a5a5a5a` value in `r13` indicates the memory was either
uninitialized, or already freed.

Unfortunately I do not have a simple self-contained test case for this.
However, it seems pretty clear that the call to `AddDbgValue()` in
`salvageDebugInfo()` causes the problems, since it modifies
`SelectionDag::DbgInfo` while looping through one of its DenseMaps:

```
void SelectionDAG::salvageDebugInfo(SDNode &N) {
[...]
  for (auto DV : GetDbgValues(&N)) {
    if (DV->isInvalidated())
      continue;
[...]
        AddDbgValue(Clone, N0.getNode(), false);
[...]
  }
}
```

At least, if I comment out the `AddDbgValue()` call, the crashes go
away.  I propose to change this function slightly, similar to the
`SelectionDAG::transferDbgValues()` function just above it, to save the
cloned SDDbgValues in a separate SmallVector, and only call
AddDbgValue() on them after the for loop is done.

Reviewers: aprantl, bogner, bkramer, davide

Reviewed By: davide

Subscribers: davide, krytarowski, JDevlieghere, emaste, llvm-commits

Differential Revision: https://reviews.llvm.org/D41589


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@321545 91177308-0d34-0410-b5e6-96231b3b80d8
kzhuravl pushed a commit that referenced this pull request Feb 9, 2018
…168)

This patch is the LLVM part of fixing the issues, described in
https://bugs.llvm.org/show_bug.cgi?id=36168

* The representation of enumerator values in the debug info metadata now
  contains a boolean flag isUnsigned, which determines how the bits of
  the value are interpreted.
* The DW_TAG_enumeration type DIE now always (for DWARF version >= 3)
  includes a DW_AT_type attribute, which refers to the underlying
  integer type, as suggested in DWARFv4 (5.7 Enumeration Type Entries).
* The debug info metadata for enumeration type contains (in flags)
  indication whether this is a C++11 "fixed enum".
* For C++11 enumeration with a fixed underlying type, the DIE also
  includes the DW_AT_enum_class attribute (for DWARF version >= 4).
* Encoding of enumerator constants uses DW_FORM_sdata for signed values
  and DW_FORM_udata for unsigned values, as suggested by DWARFv4 (7.5.4
  Attribute Encodings).

The changes should be backwards compatible:

* the isUnsigned attribute is optional and defaults to false.
* if the underlying type for the enumeration is not available, the
  enumerator values are considered signed.
* the FixedEnum flag defaults to clear.
* the bitcode format for DIEnumerator stores the unsigned flag bit #1 of
  the first record element, so the format does not change and the zero
  previously stored there is consistent with the false default for
  IsUnsigned.

Differential Revision: https://reviews.llvm.org/D42734


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324489 91177308-0d34-0410-b5e6-96231b3b80d8
kzhuravl pushed a commit that referenced this pull request Feb 16, 2018
The reference '&' is missing in the function parameter. If there are
back-to-back optimizations in terms of dag node list like below:
  t29: i64,ch = load<LD4[bitcast (%struct.test_t* @test.t to i8*)+12](dereferenceable), zext from i32> t3, t43, undef:i64
  t34: i64,ch = load<LD4[bitcast (%struct.test_t* @test.t to i8*)](dereferenceable), zext from i32> t3, t41, undef:i64
The bug will trigger a segfault for the added test case remove_truncate_5.ll:
  LLVMSymbolizer: error reading file: No such file or directory
  #0 0x000000000241c4d9 (llc+0x241c4d9)
  #1 0x000000000241c56a (llc+0x241c56a)
  #2 0x000000000241aa50 (llc+0x241aa50)
  ...
  #22 0x0000000000fd5edf (llc+0xfd5edf)
  #23 0x00007f0fe03bec05 __libc_start_main (/lib64/libc.so.6+0x21c05)
  #24 0x0000000000fd3e69 (llc+0xfd3e69)
  ...
  Segmentation fault

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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325267 91177308-0d34-0410-b5e6-96231b3b80d8
kzhuravl pushed a commit that referenced this pull request Jul 13, 2018
Spectre variant #1 for x86.

There is a lengthy, detailed RFC thread on llvm-dev which discusses the
high level issues. High level discussion is probably best there.

I've split the design document out of this patch and will land it
separately once I update it to reflect the latest edits and updates to
the Google doc used in the RFC thread.

This patch is really just an initial step. It isn't quite ready for
prime time and is only exposed via debugging flags. It has two major
limitations currently:
1) It only supports x86-64, and only certain ABIs. Many assumptions are
   currently hard-coded and need to be factored out of the code here.
2) It doesn't include any options for more fine-grained control, either
   of which control flow edges are significant or which loads are
   important to be hardened.
3) The code is still quite rough and the testing lighter than I'd like.

However, this is enough for people to begin using. I have had numerous
requests from people to be able to experiment with this patch to
understand the trade-offs it presents and how to use it. We would also
like to encourage work to similar effect in other toolchains.

The ARM folks are actively developing a system based on this for
AArch64. We hope to merge this with their efforts when both are far
enough along. But we also don't want to block making this available on
that effort.

Many thanks to the *numerous* people who helped along the way here. For
this patch in particular, both Eric and Craig did a ton of review to
even have confidence in it as an early, rough cut at this functionality.

Differential Revision: https://reviews.llvm.org/D44824

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336990 91177308-0d34-0410-b5e6-96231b3b80d8
kzhuravl pushed a commit that referenced this pull request Jul 14, 2018
…ering"

This reverts commit r337021.

WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x1415cd65 in void write_signed<long>(llvm::raw_ostream&, long, unsigned long, llvm::IntegerStyle) /code/llvm-project/llvm/lib/Support/NativeFormatting.cpp:95:7
    #1 0x1415c900 in llvm::write_integer(llvm::raw_ostream&, long, unsigned long, llvm::IntegerStyle) /code/llvm-project/llvm/lib/Support/NativeFormatting.cpp:121:3
    #2 0x1472357f in llvm::raw_ostream::operator<<(long) /code/llvm-project/llvm/lib/Support/raw_ostream.cpp:117:3
    #3 0x13bb9d4 in llvm::raw_ostream::operator<<(int) /code/llvm-project/llvm/include/llvm/Support/raw_ostream.h:210:18
    #4 0x3c2bc18 in void printField<unsigned int, &(amd_kernel_code_s::amd_kernel_code_version_major)>(llvm::StringRef, amd_kernel_code_s const&, llvm::raw_ostream&) /code/llvm-project/llvm/lib/Target/AMDGPU/Utils/AMDKernelCodeTUtils.cpp:78:23
    #5 0x3c250ba in llvm::printAmdKernelCodeField(amd_kernel_code_s const&, int, llvm::raw_ostream&) /code/llvm-project/llvm/lib/Target/AMDGPU/Utils/AMDKernelCodeTUtils.cpp:104:5
    #6 0x3c27ca3 in llvm::dumpAmdKernelCode(amd_kernel_code_s const*, llvm::raw_ostream&, char const*) /code/llvm-project/llvm/lib/Target/AMDGPU/Utils/AMDKernelCodeTUtils.cpp:113:5
    #7 0x3a46e6c in llvm::AMDGPUTargetAsmStreamer::EmitAMDKernelCodeT(amd_kernel_code_s const&) /code/llvm-project/llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUTargetStreamer.cpp:161:3
    #8 0xd371e4 in llvm::AMDGPUAsmPrinter::EmitFunctionBodyStart() /code/llvm-project/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp:204:26

[...]

Uninitialized value was created by an allocation of 'KernelCode' in the stack frame of function '_ZN4llvm16AMDGPUAsmPrinter21EmitFunctionBodyStartEv'
    #0 0xd36650 in llvm::AMDGPUAsmPrinter::EmitFunctionBodyStart() /code/llvm-project/llvm/lib/Target/AMDGPU/AMDGPUAsmPrinter.cpp:192

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337079 91177308-0d34-0410-b5e6-96231b3b80d8
kzhuravl pushed a commit that referenced this pull request Jul 17, 2018
This patch completes support for the following floating point
instructions that take FP immediates:
  FADD*  (addition)
  FSUB   (subtract)
  FSUBR  (subtract reverse form)
  FMUL*  (multiplication)
  FMAX*  (maximum)
  FMAXNM (maximum number)
  FMIN   (maximum)
  FMINNM (maximum number)

All operations are predicated and take a FP immediate operand,
e.g.

  fadd z0.h, p0/m, z0.h, #0.5
  fmin z0.s, p0/m, z0.s, #1.0
        ^___________^ (tied)

* Instructions added in a previous patch.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337272 91177308-0d34-0410-b5e6-96231b3b80d8
kzhuravl pushed a commit that referenced this pull request Jul 19, 2018
changes that are intertwined here:

1) Extracting the tracing of predicate state through the CFG to its own
   function.
2) Creating a struct to manage the predicate state used throughout the
   pass.

Doing #1 necessitates and motivates the particular approach for #2 as
now the predicate management is spread across different functions
focused on different aspects of it. A number of simplifications then
fell out as a direct consequence.

I went with an Optional to make it more natural to construct the
MachineSSAUpdater object.

This is probably the single largest outstanding refactoring step I have.
Things get a bit more surgical from here. My current goal, beyond
generally making this maintainable long-term, is to implement several
improvements to how we do interprocedural tracking of predicate state.
But I don't want to do that until the predicate state management and
tracing is in reasonably clear state.

Differential Revision: https://reviews.llvm.org/D49427

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337446 91177308-0d34-0410-b5e6-96231b3b80d8
kzhuravl pushed a commit that referenced this pull request Jul 23, 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
kzhuravl 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
kzhuravl pushed a commit that referenced this pull request Aug 30, 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
kzhuravl pushed a commit that referenced this pull request Sep 16, 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
kzhuravl pushed 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.

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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@343961 91177308-0d34-0410-b5e6-96231b3b80d8
kzhuravl 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
kzhuravl pushed a commit that referenced this pull request Oct 12, 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
kzhuravl pushed a commit that referenced this pull request Oct 26, 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
kzhuravl 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
kzhuravl 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
kzhuravl pushed a commit that referenced this pull request Nov 15, 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
kzhuravl pushed a commit that referenced this pull request Jan 31, 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
kzhuravl pushed a commit that referenced this pull request Mar 1, 2019
kzhuravl pushed a commit that referenced this pull request Mar 7, 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
kzhuravl 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
kzhuravl 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
kzhuravl 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
kzhuravl 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
kzhuravl 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
kzhuravl 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
kzhuravl pushed a commit that referenced this pull request Jul 11, 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
kzhuravl 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
kzhuravl pushed a commit that referenced this pull request Aug 14, 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
kzhuravl pushed a commit that referenced this pull request Aug 27, 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
kzhuravl pushed a commit that referenced this pull request Sep 2, 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
kzhuravl 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
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

1 participant