TableGen getting miscompiled Re: Buildbot failure in LLVM Buildbot on ppc64le-lld-multistage-test

[Roman Lebedev via llvm-commits]

Hello all.

While i've +CC'd some PPC people to this mail,
although i'm not sure if someone else should also be CC'd.

My change, https://github.com/llvm/llvm-project/commit/3c4d2a03968ccf5889bacffe02d6fa2443b0260f,
and earlier https://github.com/llvm/llvm-project/commit/cf624b23bc5d5a6161706d1663def49380ff816a,
is causing or exposing some miscompilation of TableGen on PowerPC:
https://lab.llvm.org/buildbot/#/builders/121/builds/25570
https://lab.llvm.org/buildbot#builders/36/builds/27662

So far, i haven't had reports that other architectures are affected.

I don't have any means to investigate this problem,
i don't have any relevant hardware, or access to such hardware,
nor experience with that architecture,
so i would need help to deal with this issue.
Ideally, i would love to get an actionable reproducer,
but perhaps that is too much to hope for.

Roman

On Sat, Nov 26, 2022 at 11:34 PM <llvm.buildmaster at lab.llvm.org> wrote:
>
> The Buildbot has detected a failed build on builder ppc64le-lld-multistage-test while building clang,llvm.
>
> Full details are available at:
>     https://lab.llvm.org/buildbot#builders/36/builds/27662
>
> Worker for this Build: ppc64le-lld-multistage-test
> Blamelist:
>     Roman Lebedev <lebedev.ri at gmail.com>
>
> BUILD FAILED: failed build (failure)
>
> Step 12 (build-stage2-unified-tree) failure: build (failure)
> ...
> 17.522 [1/8/14] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/ClangOptionDocEmitter.cpp.o
> 17.622 [1/7/15] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/RISCVVEmitter.cpp.o
> 28.778 [1/6/16] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/ClangOpenCLBuiltinEmitter.cpp.o
> 30.149 [1/5/17] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/SveEmitter.cpp.o
> 35.802 [1/4/18] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/ClangDiagnosticsEmitter.cpp.o
> 48.328 [1/3/19] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/MveEmitter.cpp.o
> 59.202 [1/2/20] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/NeonEmitter.cpp.o
> 83.871 [1/1/21] Building CXX object tools/clang/utils/TableGen/CMakeFiles/clang-tblgen.dir/ClangAttrEmitter.cpp.o
> 83.976 [0/1/22] Linking CXX executable bin/clang-tblgen
> 239.711 [1945/888/2786] Building CXX object lib/Target/ARM/MCTargetDesc/CMakeFiles/LLVMARMDesc.dir/ARMInstPrinter.cpp.o
> FAILED: lib/Target/ARM/MCTargetDesc/CMakeFiles/LLVMARMDesc.dir/ARMInstPrinter.cpp.o
> CCACHE_CPP2=yes CCACHE_HASHDIR=yes /usr/bin/ccache /home/buildbots/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/install/stage1/bin/clang++  -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Ilib/Target/ARM/MCTargetDesc -I/home/buildbots/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/lib/Target/ARM/MCTargetDesc -I/home/buildbots/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/lib/Target/ARM -Ilib/Target/ARM -Iinclude -I/home/buildbots/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/include -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -pedantic -Wno-long-long -Wc++98-compat-extra-semi -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dto
>  r -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -O3 -DNDEBUG -fvisibility=hidden    -fno-exceptions -fno-rtti -UNDEBUG -std=c++17 -MD -MT lib/Target/ARM/MCTargetDesc/CMakeFiles/LLVMARMDesc.dir/ARMInstPrinter.cpp.o -MF lib/Target/ARM/MCTargetDesc/CMakeFiles/LLVMARMDesc.dir/ARMInstPrinter.cpp.o.d -o lib/Target/ARM/MCTargetDesc/CMakeFiles/LLVMARMDesc.dir/ARMInstPrinter.cpp.o -c /home/buildbots/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/lib/Target/ARM/MCTargetDesc/ARMInstPrinter.cpp
> In file included from /home/buildbots/ppc64le-lld-multistage-test/ppc64le-lld-multistage-test/llvm-project/llvm/lib/Target/ARM/MCTargetDesc/ARMInstPrinter.cpp:38:
> lib/Target/ARM/ARMGenAsmWriter.inc:12148:10: error: duplicate case value 'VMOVRRS'
>     case ARM::VMOVRRS:
>          ^
> lib/Target/ARM/ARMGenAsmWriter.inc:12146:10: note: previous case defined here
>     case ARM::VMOVRRS:
>          ^
> lib/Target/ARM/ARMGenAsmWriter.inc:12149:10: error: duplicate case value 'VMOVSRR'
>     case ARM::VMOVSRR:
>          ^
> lib/Target/ARM/ARMGenAsmWriter.inc:12145:10: note: previous case defined here
>     case ARM::VMOVSRR:
>          ^
> lib/Target/ARM/ARMGenAsmWriter.inc:12214:10: error: duplicate case value 'VST3d16'
>     case ARM::VST3d16:
>          ^
> lib/Target/ARM/ARMGenAsmWriter.inc:12112:10: note: previous case defined here
>     case ARM::VST3d16:
>          ^
> lib/Target/ARM/ARMGenAsmWriter.inc:12215:10: error: duplicate case value 'VST3d32'
>     case ARM::VST3d32:
>          ^
> lib/Target/ARM/ARMGenAsmWriter.inc:12111:10: note: previous case defined here
>     case ARM::VST3d32:
>          ^
> lib/Target/ARM/ARMGenAsmWriter.inc:12216:10: error: duplicate case value 'VST3d8'
>     case ARM::VST3d8:
>          ^
> lib/Target/ARM/ARMGenAsmWriter.inc:12110:10: note: previous case defined here
>     case ARM::VST3d8:
>          ^
> lib/Target/ARM/ARMGenAsmWriter.inc:12217:10: error: duplicate case value 'VST3q16'
>     case ARM::VST3q16:
>          ^
> lib/Target/ARM/ARMGenAsmWriter.inc:12080:10: note: previous case defined here
>     case ARM::VST3q16:
>          ^
>
> Sincerely,
> LLVM Buildbot
>