Comment 1 for bug 1887557

Created attachment 48847
preprocessed unreduced testcase

The testcase, extracted from current mesa, segfaults with -O1 or higher:

# gcc -O1 -c sp_tex_sample.i
during IPA pass: fnsummary
../mesa-9999/src/gallium/drivers/softpipe/sp_tex_sample.c: In function 'sample_compare':
../mesa-9999/src/gallium/drivers/softpipe/sp_tex_sample.c:3862:1: internal compiler error: Segmentation fault
 3862 | }
      | ^
Please submit a full bug report,
with preprocessed source if appropriate.

# gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/10.1.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /tmp-ram/portage/sys-devel/gcc-10.1.0-r1/work/gcc-10.1.0/configure --host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/10.1.0 --includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/10.1.0/include --datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/10.1.0 --mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/10.1.0/man --infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/10.1.0/info --with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/10.1.0/include/g++-v10 --with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/10.1.0/python --enable-languages=c,c++ --enable-obsolete --enable-secureplt --disable-werror --with-system-zlib --disable-nls --enable-checking=release --with-bugurl=https://bugs.gentoo.org/ --with-pkgversion='Gentoo 10.1.0-r1 p2' --disable-esp --enable-libstdcxx-time --with-build-config=bootstrap-lto --enable-shared --enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu --enable-multilib --with-multilib-list=m32,m64 --disable-fixed-point --enable-targets=all --enable-libgomp --disable-libmudflap --disable-libssp --disable-libada --disable-systemtap --disable-vtable-verify --disable-libvtv --without-zstd --disable-libquadmath --enable-lto --with-isl --disable-isl-version-check --disable-libsanitizer --disable-default-pie --disable-default-ssp
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 10.1.0 (Gentoo 10.1.0-r1 p2)