[llvm] [X86] Add TuningSlowPDEP/PEXT flags and control vector PDEP/PEXT scalarization with them (PR #218980)

Thu Aug 27 05:56:36 PDT 2026

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `ml-opt-rel-x86-64` running on `ml-opt-rel-x86-64-b1` while building `llvm` at step 5 "annotate".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/185/builds/1639

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 5 (annotate) failure: '../llvm-zorg/zorg/buildbot/builders/annotated/mlgo-emitc.sh --jobs=64' (failure)
...
UNSUPPORTED: LLVM :: tools/llvm-exegesis/PowerPC/latency-by-opcode-name.s (67131 of 67142)
UNSUPPORTED: LLVM :: tools/lto/discard-value-names.ll (67132 of 67142)
UNSUPPORTED: LLVM :: CodeGen/CSKY/inline-asm.ll (67133 of 67142)
UNSUPPORTED: LLVM :: CodeGen/DirectX/ShaderFlags/use-native-low-precision-0.ll (67134 of 67142)
UNSUPPORTED: LLVM :: CodeGen/DirectX/WavePrefixBitCount.ll (67135 of 67142)
UNSUPPORTED: LLVM :: CodeGen/Xtensa/bswap.ll (67136 of 67142)
UNSUPPORTED: LLVM :: CodeGen/Xtensa/simple.ll (67137 of 67142)
UNSUPPORTED: LLVM :: MC/CSKY/lrw.s (67138 of 67142)
UNSUPPORTED: LLVM :: MC/M68k/Arith/Classes/MxBiArOp_RFRR_EAd.s (67139 of 67142)
UNSUPPORTED: LLVM :: MC/M68k/Bits/Classes/MxBTST_RR.s (67140 of 67142)
FAIL: LLVM :: CodeGen/X86/znver-pdep.ll (67141 of 67142)
******************** TEST 'LLVM :: CodeGen/X86/znver-pdep.ll' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 2
/b/build/llvm-project/build-mlgo/bin/llc < /b/build/llvm-project/llvm/test/CodeGen/X86/znver-pdep.ll -mtriple=x86_64-- -mcpu=znver1 | /b/build/llvm-project/build-mlgo/bin/FileCheck /b/build/llvm-project/llvm/test/CodeGen/X86/znver-pdep.ll --check-prefixes=CHECK,SLOW-ZNVER
# executed command: /b/build/llvm-project/build-mlgo/bin/llc -mtriple=x86_64-- -mcpu=znver1
# executed command: /b/build/llvm-project/build-mlgo/bin/FileCheck /b/build/llvm-project/llvm/test/CodeGen/X86/znver-pdep.ll --check-prefixes=CHECK,SLOW-ZNVER
# .---command stderr------------
# | /b/build/llvm-project/llvm/test/CodeGen/X86/znver-pdep.ll:1013:15: error: CHECK-NEXT: is not on the line after the previous match
# | ; CHECK-NEXT: pdepl %eax, %ecx, %eax
# |               ^
# | <stdin>:495:2: note: 'next' match was here
# |  pdepl %eax, %ecx, %eax
# |  ^
# | <stdin>:493:19: note: previous match ended here
# |  vmovd %xmm0, %edx
# |                   ^
# | <stdin>:494:1: note: non-matching line after previous match is here
# |  vpextrd $2, %xmm0, %esi
# | ^
# | /b/build/llvm-project/llvm/test/CodeGen/X86/znver-pdep.ll:1036:15: error: CHECK-NEXT: is not on the line after the previous match
# | ; CHECK-NEXT: vpextrd $1, %xmm2, %eax
# |               ^
# | <stdin>:519:2: note: 'next' match was here
# |  vpextrd $1, %xmm2, %eax
# |  ^
# | <stdin>:516:31: note: previous match ended here
# |  vextracti128 $1, %ymm1, %xmm2
# |                               ^
# | <stdin>:517:1: note: non-matching line after previous match is here
# |  vpextrd $1, %xmm0, %r8d
# | ^
# | /b/build/llvm-project/llvm/test/CodeGen/X86/znver-pdep.ll:1079:15: error: CHECK-NEXT: expected string not found in input
# | ; CHECK-NEXT: vmovq %xmm1, %rdx
# |               ^
# | <stdin>:559:25: note: scanning from here
Step 8 (Run tests) failure: Run tests (failure)
...
UNSUPPORTED: LLVM :: tools/llvm-exegesis/PowerPC/latency-by-opcode-name.s (67131 of 67142)
UNSUPPORTED: LLVM :: tools/lto/discard-value-names.ll (67132 of 67142)
UNSUPPORTED: LLVM :: CodeGen/CSKY/inline-asm.ll (67133 of 67142)
UNSUPPORTED: LLVM :: CodeGen/DirectX/ShaderFlags/use-native-low-precision-0.ll (67134 of 67142)
UNSUPPORTED: LLVM :: CodeGen/DirectX/WavePrefixBitCount.ll (67135 of 67142)
UNSUPPORTED: LLVM :: CodeGen/Xtensa/bswap.ll (67136 of 67142)
UNSUPPORTED: LLVM :: CodeGen/Xtensa/simple.ll (67137 of 67142)
UNSUPPORTED: LLVM :: MC/CSKY/lrw.s (67138 of 67142)
UNSUPPORTED: LLVM :: MC/M68k/Arith/Classes/MxBiArOp_RFRR_EAd.s (67139 of 67142)
UNSUPPORTED: LLVM :: MC/M68k/Bits/Classes/MxBTST_RR.s (67140 of 67142)
FAIL: LLVM :: CodeGen/X86/znver-pdep.ll (67141 of 67142)
******************** TEST 'LLVM :: CodeGen/X86/znver-pdep.ll' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 2
/b/build/llvm-project/build-mlgo/bin/llc < /b/build/llvm-project/llvm/test/CodeGen/X86/znver-pdep.ll -mtriple=x86_64-- -mcpu=znver1 | /b/build/llvm-project/build-mlgo/bin/FileCheck /b/build/llvm-project/llvm/test/CodeGen/X86/znver-pdep.ll --check-prefixes=CHECK,SLOW-ZNVER
# executed command: /b/build/llvm-project/build-mlgo/bin/llc -mtriple=x86_64-- -mcpu=znver1
# executed command: /b/build/llvm-project/build-mlgo/bin/FileCheck /b/build/llvm-project/llvm/test/CodeGen/X86/znver-pdep.ll --check-prefixes=CHECK,SLOW-ZNVER
# .---command stderr------------
# | /b/build/llvm-project/llvm/test/CodeGen/X86/znver-pdep.ll:1013:15: error: CHECK-NEXT: is not on the line after the previous match
# | ; CHECK-NEXT: pdepl %eax, %ecx, %eax
# |               ^
# | <stdin>:495:2: note: 'next' match was here
# |  pdepl %eax, %ecx, %eax
# |  ^
# | <stdin>:493:19: note: previous match ended here
# |  vmovd %xmm0, %edx
# |                   ^
# | <stdin>:494:1: note: non-matching line after previous match is here
# |  vpextrd $2, %xmm0, %esi
# | ^
# | /b/build/llvm-project/llvm/test/CodeGen/X86/znver-pdep.ll:1036:15: error: CHECK-NEXT: is not on the line after the previous match
# | ; CHECK-NEXT: vpextrd $1, %xmm2, %eax
# |               ^
# | <stdin>:519:2: note: 'next' match was here
# |  vpextrd $1, %xmm2, %eax
# |  ^
# | <stdin>:516:31: note: previous match ended here
# |  vextracti128 $1, %ymm1, %xmm2
# |                               ^
# | <stdin>:517:1: note: non-matching line after previous match is here
# |  vpextrd $1, %xmm0, %r8d
# | ^
# | /b/build/llvm-project/llvm/test/CodeGen/X86/znver-pdep.ll:1079:15: error: CHECK-NEXT: expected string not found in input
# | ; CHECK-NEXT: vmovq %xmm1, %rdx
# |               ^
# | <stdin>:559:25: note: scanning from here

```

</details>

https://github.com/llvm/llvm-project/pull/218980