https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115961
Bug ID: 115961
Summary: [15 Regression] wrong code on llvm-18.1.8 since
r15-1936-g80e446e829d818
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: slyfox at gcc dot gnu.org
Target Milestone: ---
Initially observed the failure on r15-1936-g80e446e829d818 compiler on
llvm-18.1.8 testsuite as failures:
Failed Tests (22):
LLVM :: CodeGen/AArch64/regalloc-last-chance-recolor-with-split.mir
LLVM :: CodeGen/AArch64/tail-dup-redundant-phi.mir
LLVM :: CodeGen/AMDGPU/GlobalISel/llvm.amdgcn.image.load.2darraymsaa.ll
LLVM :: CodeGen/AMDGPU/GlobalISel/llvm.amdgcn.image.load.3d.ll
LLVM :: CodeGen/AMDGPU/InlineAsmCrash.ll
LLVM :: CodeGen/AMDGPU/llvm.amdgcn.image.dim.ll
LLVM :: CodeGen/AMDGPU/llvm.amdgcn.image.gather4.dim.ll
LLVM :: CodeGen/AMDGPU/llvm.amdgcn.image.msaa.load.x.ll
LLVM :: CodeGen/AMDGPU/llvm.amdgcn.image.sample.d16.dim.ll
LLVM :: CodeGen/AMDGPU/llvm.amdgcn.image.sample.dim.ll
LLVM :: CodeGen/PowerPC/inlineasm-copy.ll
LLVM :: CodeGen/SystemZ/asm-18.ll
LLVM :: CodeGen/X86/callbr-asm-outputs.ll
LLVM :: CodeGen/X86/statepoint-fixup-invoke.mir
LLVM :: CodeGen/X86/statepoint-fixup-shared-ehpad.mir
LLVM :: CodeGen/X86/statepoint-fixup-undef-def.mir
LLVM :: CodeGen/X86/statepoint-invoke-ra-enter-at-end.mir
LLVM :: CodeGen/X86/statepoint-invoke-ra-inline-spiller.mir
LLVM :: CodeGen/X86/statepoint-invoke-ra.mir
LLVM :: CodeGen/X86/statepoint-vreg-folding.mir
LLVM :: CodeGen/X86/statepoint-vreg-twoaddr.mir
LLVM :: CodeGen/X86/statepoint-vreg.mir
Bisected down to r15-1936-g80e446e829d818: "Match: Support form 2 for the
.SAT_TRUNC".
Here is the minimized example that exhibits the failure:
Ok:
$ g++ -O1 a.cc -o a && ./a
Bad:
$ g++ -O2 a.cc -o a && ./a
Illegal instruction (core dumped)
/nix/store/lr4n7v61gnijc5jnvrgjhqklcvqsds40-gcc-wrapper-15.0.0/bin/g++ -v |&
unnix
Using built-in specs.
COLLECT_GCC=/<<NIX>>/gcc-15.0.0/bin/g++
COLLECT_LTO_WRAPPER=/<<NIX>>/gcc-15.0.0/libexec/gcc/x86_64-unknown-linux-gnu/15.0.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../source/configure --prefix=/<<NIX>>/gcc-15.0.0
--with-gmp-include=/<<NIX>>/gmp-6.3.0-dev/include
--with-gmp-lib=/<<NIX>>/gmp-6.3.0/lib
--with-mpfr-include=/<<NIX>>/mpfr-4.2.1-dev/include
--with-mpfr-lib=/<<NIX>>/mpfr-4.2.1/lib --with-mpc=/<<NIX>>/libmpc-1.3.1
--with-native-system-header-dir=/<<NIX>>/glibc-2.39-52-dev/include
--with-build-sysroot=/
--with-gxx-include-dir=/<<NIX>>/gcc-15.0.0/include/c++/15.0.0/
--program-prefix= --enable-lto --disable-libstdcxx-pch
--without-included-gettext --with-system-zlib --enable-checking=release
--enable-static --enable-languages=c,c++ --disable-multilib --enable-plugin
--disable-libcc1 --with-isl=/<<NIX>>/isl-0.20 --disable-bootstrap
--build=x86_64-unknown-linux-gnu --host=x86_64-unknown-linux-gnu
--target=x86_64-unknown-linux-gnu
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 15.0.0 99999999 (experimental) (GCC)
