https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110515
Bug ID: 110515
Summary: [14 Regression] llvm-15.0.7 possibly invalid code on
-O3
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: slyfox at gcc dot gnu.org
Target Milestone: ---
Created attachment 55447
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55447&action=edit
DwarfCompileUnit.cpp
Initially the failure is observed on r14-2233-gfca6d9c12f5bf0 where llvm-15.0.7
test suite fails a single test:
Failed Tests (1):
LLVM :: DebugInfo/X86/vla-multi.ll
I think I shrunk it down to DwarfCompileUnit.cpp:
$ g++ -std=c++14 DwarfCompileUnit.cpp -O2 $cxxflags -o bug-O2 && ./bug-O2
Illegal instruction (core dumped)
$ g++ -std=c++14 DwarfCompileUnit.cpp -O1 $cxxflags -o bug-O1 && ./bug-O1
<ok>
It's a very fragile test:
- any inlines I try seem to repair the test
- -fno-strict-aliasing unbreaks it (I believe the code is strict-aliasing
clean)
- optimization option changes repair the test
$ g++ -v
Using built-in specs.
COLLECT_GCC=/<<NIX>>/gcc-14.0.0/bin/g++
COLLECT_LTO_WRAPPER=/<<NIX>>/gcc-14.0.0/libexec/gcc/x86_64-unknown-linux-gnu/14.0.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with:
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 14.0.0 99999999 (experimental) (GCC)
