https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122843
Bug ID: 122843
Summary: [16 Regression] Excessive compile time with flags -O2
-fpeel-loops -march=znver3
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: dcb314 at hotmail dot com
Target Milestone: ---
Created attachment 62899
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=62899&action=edit
C source code
A simple case:
foundBugs $ time ../results/bin/gcc -O2 -march=znver3 -c -w bug1144.c
real 0m0.539s
user 0m0.510s
sys 0m0.019s
Something slightly more complex appears to cause trouble:
foundBugs $ (ulimit -t 60; time ../results/bin/gcc -O2 -fpeel-loops
-march=znver3 -c -w bug1144.c)
gcc: fatal error: Killed signal terminated program cc1
compilation terminated.
real 1m0.859s
user 0m58.810s
sys 0m1.408s
foundBugs $
for this compiler:
foundBugs $ ../results/bin/gcc -v
Using built-in specs.
COLLECT_GCC=../results/bin/gcc
COLLECT_LTO_WRAPPER=/home/dcb42/gcc/results.20251125.asan.ubsan/libexec/gcc/x86_64-pc-linux-gnu/16.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../trunk/configure
--prefix=/home/dcb42/gcc/results.20251125.asan.ubsan --disable-bootstrap
--disable-doc --disable-multilib --with-build-config='bootstrap-asan
bootstrap-ubsan' --with-pkgversion=994844d82f8e47a2 --with-isl
--enable-checking=df,extra,fold,rtl,yes --enable-languages=c,c++,fortran
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 16.0.0 20251125 (experimental) (994844d82f8e47a2)
foundBugs $
The problem first seems to occur sometime between g:ebabae605093e5a3,
dated 20251121 and g:a8d172b5ff6d61b9, dated 20251123.
