dont-shuffle-bswaps codegen test broken on none-x86_64/arm64 archs

[Fabian-Gruenbichler]

Summary

the test case introduced by #136761 is broken on at least loong64, ppc64el, mips64el and ppc64.

Command used

./x test tests/codegen/dont-shuffle-bswaps.rs --target powerpc64le-unknown-linux-gnu

Expected behaviour

the test should pass, or be ignored

Actual behaviour

the test fails because the FileCheck annotations don't match (because of missing vectorisation?)

Operating system

Debian experimental

HEAD

425e142686242c7e73f5e32c79071ae266f0f355

Additional context

Test output

------FileCheck stderr------------------------------
/build/reproducible-path/rustc-1.86.0+dfsg1/tests/codegen/dont-shuffle-bswaps.rs:17:10: error: OPT3: expected string not found in input
// OPT3: load <8 x i16>
         ^
/build/reproducible-path/rustc-1.86.0+dfsg1/build/powerpc64-unknown-linux-gnu/test/codegen/dont-shuffle-bswaps.OPT3/dont-shuffle-bswaps.ll:7:22: note: scanning from here
define void @convert(ptr dead_on_unwind noalias nocapture noundef writable writeonly sret([16 x i8]) align 1 dereferenceable(16) %_0, ptr noalias nocapture noundef readonly align 2 dereferenceable(16) %value) unnamed_addr #0 {
                     ^
/build/reproducible-path/rustc-1.86.0+dfsg1/build/powerpc64-unknown-linux-gnu/test/codegen/dont-shuffle-bswaps.OPT3/dont-shuffle-bswaps.ll:9:8: note: possible intended match here
 %_4 = load i16, ptr %value, align 2, !noundef !2
       ^

Input file: /build/reproducible-path/rustc-1.86.0+dfsg1/build/powerpc64-unknown-linux-gnu/test/codegen/dont-shuffle-bswaps.OPT3/dont-shuffle-bswaps.ll
Check file: /build/reproducible-path/rustc-1.86.0+dfsg1/tests/codegen/dont-shuffle-bswaps.rs

-dump-input=help explains the following input dump.

Input was:
<<<<<<
            1: ; ModuleID = 'dont_shuffle_bswaps.5c93dbc6d133cf57-cgu.0' 
            2: source_filename = "dont_shuffle_bswaps.5c93dbc6d133cf57-cgu.0" 
            3: target datalayout = "E-m:e-Fi64-i64:64-n32:64-S128-v256:256:256-v512:512:512" 
            4: target triple = "powerpc64-unknown-linux-gnu" 
            5:  
            6: ; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(argmem: readwrite) uwtable 
            7: define void @convert(ptr dead_on_unwind noalias nocapture noundef writable writeonly sret([16 x i8]) align 1 dereferenceable(16) %_0, ptr noalias nocapture noundef readonly align 2 dereferenceable(16) %value) unnamed_addr #0 { 
check:17'0                          X~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ error: no match found
            8: start: 
check:17'0     ~~~~~~~
            9:  %_4 = load i16, ptr %value, align 2, !noundef !2 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
check:17'1            ?                                           possible intended match
           10:  %0 = tail call i16 @llvm.bswap.i16(i16 %_4) 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           11:  %1 = getelementptr inbounds i8, ptr %value, i64 2 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           12:  %_6 = load i16, ptr %1, align 2, !noundef !2 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           13:  %2 = tail call i16 @llvm.bswap.i16(i16 %_6) 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           14:  %3 = getelementptr inbounds i8, ptr %value, i64 4 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           15:  %_8 = load i16, ptr %3, align 2, !noundef !2 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           16:  %4 = tail call i16 @llvm.bswap.i16(i16 %_8) 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           17:  %5 = getelementptr inbounds i8, ptr %value, i64 6 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           18:  %_10 = load i16, ptr %5, align 2, !noundef !2 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           19:  %6 = tail call i16 @llvm.bswap.i16(i16 %_10) 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           20:  %7 = getelementptr inbounds i8, ptr %value, i64 8 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           21:  %_12 = load i16, ptr %7, align 2, !noundef !2 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           22:  %8 = tail call i16 @llvm.bswap.i16(i16 %_12) 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           23:  %9 = getelementptr inbounds i8, ptr %value, i64 10 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           24:  %_14 = load i16, ptr %9, align 2, !noundef !2 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           25:  %10 = tail call i16 @llvm.bswap.i16(i16 %_14) 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           26:  %11 = getelementptr inbounds i8, ptr %value, i64 12 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           27:  %_16 = load i16, ptr %11, align 2, !noundef !2 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           28:  %12 = tail call i16 @llvm.bswap.i16(i16 %_16) 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           29:  %13 = getelementptr inbounds i8, ptr %value, i64 14 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           30:  %_18 = load i16, ptr %13, align 2, !noundef !2 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           31:  %14 = tail call i16 @llvm.bswap.i16(i16 %_18) 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           32:  store i16 %0, ptr %_0, align 1 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           33:  %addr16.sroa.2.0._0.sroa_idx = getelementptr inbounds i8, ptr %_0, i64 2 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           34:  store i16 %2, ptr %addr16.sroa.2.0._0.sroa_idx, align 1 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           35:  %addr16.sroa.3.0._0.sroa_idx = getelementptr inbounds i8, ptr %_0, i64 4 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           36:  store i16 %4, ptr %addr16.sroa.3.0._0.sroa_idx, align 1 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           37:  %addr16.sroa.4.0._0.sroa_idx = getelementptr inbounds i8, ptr %_0, i64 6 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           38:  store i16 %6, ptr %addr16.sroa.4.0._0.sroa_idx, align 1 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           39:  %addr16.sroa.5.0._0.sroa_idx = getelementptr inbounds i8, ptr %_0, i64 8 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           40:  store i16 %8, ptr %addr16.sroa.5.0._0.sroa_idx, align 1 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           41:  %addr16.sroa.6.0._0.sroa_idx = getelementptr inbounds i8, ptr %_0, i64 10 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           42:  store i16 %10, ptr %addr16.sroa.6.0._0.sroa_idx, align 1 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           43:  %addr16.sroa.7.0._0.sroa_idx = getelementptr inbounds i8, ptr %_0, i64 12 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           44:  store i16 %12, ptr %addr16.sroa.7.0._0.sroa_idx, align 1 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           45:  %addr16.sroa.8.0._0.sroa_idx = getelementptr inbounds i8, ptr %_0, i64 14 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           46:  store i16 %14, ptr %addr16.sroa.8.0._0.sroa_idx, align 1 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           47:  ret void 
check:17'0     ~~~~~~~~~~
           48: } 
check:17'0     ~~
           49:  
check:17'0     ~
           50: ; Function Attrs: mustprogress nocallback nofree nosync nounwind speculatable willreturn memory(none) 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           51: declare i16 @llvm.bswap.i16(i16) #1 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           52:  
check:17'0     ~
           53: attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(argmem: readwrite) uwtable "probe-stack"="inline-asm" "target-cpu"="ppc64" } 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           54: attributes #1 = { mustprogress nocallback nofree nosync nounwind speculatable willreturn memory(none) } 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           55:  
check:17'0     ~
           56: !llvm.module.flags = !{!0} 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~
           57: !llvm.ident = !{!1} 
check:17'0     ~~~~~~~~~~~~~~~~~~~~
           58:  
check:17'0     ~
           59: !0 = !{i32 8, !"PIC Level", i32 2} 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           60: !1 = !{!"rustc version 1.86.0 (05f9846f8 2025-03-31) (built from a source tarball)"} 
check:17'0     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           61: !2 = !{} 
check:17'0     ~~~~~~~~~
>>>>>>

------------------------------------------

error in revision `OPT3`: verification with 'FileCheck' failed
status: exit status: 1

[onur-ozkan]

Command used
Debian packaging build

Please update this part in the issue.

[Fabian-Gruenbichler]

done (also added HEAD, after verifying it reproduces with plain upstream sources easily. note that you need a working cross setup or run it on one of the affected targets natively.

[workingjubilee]

This test was not introduced by that PR.

[workingjubilee]

@Fabian-Gruenbichler Do both revisions fail, or only the OPT3 one?

[workingjubilee]

...damn, that codegen sucks ass?

[nikic]

That tests seems to assume that every 64-bit target has a cheap <8 x i16> bswap, which is obviously not true. E.g. this is how mips64el looks like: https://llvm.godbolt.org/z/9K57M5z8o

This test should be limited to known-good arches.

[workingjubilee]

Yes, but Power ISA has a vector byte-reverse. Is our powerpc64le target too low an architectural level for that?

[workingjubilee]

ppc64le implies Power 8: https://github.com/llvm/llvm-project/blob/eb6577d54f53715e8917cf8a91eb68c8b47d489f/llvm/lib/Target/PowerPC/PPC.td#L713

Which should imply VSX is available and thus xxbrh is usable? Is that seriously worse than its current assembly?

[workingjubilee]

...well, I'll confess that's not what I expected the assembly to be on Power 8 of llvm.bswap on a vector.

test:                                   # @test
.Lfunc_gep0:
        addis 2, 12, .TOC.-.Lfunc_gep0@ha
        addi 2, 2, .TOC.-.Lfunc_gep0@l
        lxvd2x 0, 0, 3
        addis 4, 2, .LCPI0_0@toc@ha
        addi 4, 4, .LCPI0_0@toc@l
        xxswapd 34, 0
        lxvd2x 0, 0, 4
        xxswapd 35, 0
        vperm 2, 2, 2, 3
        xxswapd 0, 34
        stxvd2x 0, 0, 3
        blr

@jieyouxu is there some form of //@ only-x86_64-or-aarch64 directive?