[Bug c++/110742] New: [14 Regression] cc1plus ICE "Floating point exception" during profiled bootstrap since commit 08b99fe8ad6

["thiago.bauermann at linaro dot org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110742

            Bug ID: 110742
           Summary: [14 Regression] cc1plus ICE "Floating point exception"
                    during profiled bootstrap since commit 08b99fe8ad6
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: thiago.bauermann at linaro dot org
                CC: saaadhu at gcc dot gnu.org
  Target Milestone: ---
              Host: armv8l-unknown-linux-gnueabihf
            Target: armv8l-unknown-linux-gnueabihf

Created attachment 55583
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55583&action=edit
Output of running with "-v -save-temps -freport-bug".

Our CI detected that commit 08b99fe8ad6c "ira: Skip empty regclass when setting
up reg class relations" introduced an ICE in a profiled bootstrap build on
armv8l-linux-gnueabihf:

/home/thiago.bauermann/.cache/builds/gcc-native-aarch32/./prev-gcc/xg++
-B/home/thiago.bauermann/.cache/builds/gcc-native-aarch32/./prev-gcc/
-B/usr/local/armv8l-unknown-linux-gnueabihf/bin/ -nostdinc++
-B/home/thiago.bauermann/.cache/builds/gcc-native-aarch32/prev-armv8l-unknown-linux-gnueabihf/libstdc++-v3/src/.libs
-B/home/thiago.bauermann/.cache/builds/gcc-native-aarch32/prev-armv8l-unknown-linux-gnueabihf/libstdc++-v3/libsupc++/.libs

-I/home/thiago.bauermann/.cache/builds/gcc-native-aarch32/prev-armv8l-unknown-linux-gnueabihf/libstdc++-v3/include/armv8l-unknown-linux-gnueabihf

-I/home/thiago.bauermann/.cache/builds/gcc-native-aarch32/prev-armv8l-unknown-linux-gnueabihf/libstdc++-v3/include
 -I/home/thiago.bauermann/src/gcc/libstdc++-v3/libsupc++
-L/home/thiago.bauermann/.cache/builds/gcc-native-aarch32/prev-armv8l-unknown-linux-gnueabihf/libstdc++-v3/src/.libs
-L/home/thiago.bauermann/.cache/builds/gcc-native-aarch32/prev-armv8l-unknown-linux-gnueabihf/libstdc++-v3/libsupc++/.libs
 -fno-PIE -c   -g -O2 -fno-checking -gtoggle -fprofile-generate -DIN_GCC   
-fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing
-Wwrite-strings -Wcast-qual -Wmissing-format-attribute
-Wconditionally-supported -Woverloaded-virtual -pedantic -Wno-long-long
-Wno-variadic-macros -Wno-overlength-strings -fno-common  -DHAVE_CONFIG_H
-fno-PIE -I. -I. -I/home/thiago.bauermann/src/gcc/gcc
-I/home/thiago.bauermann/src/gcc/gcc/.
-I/home/thiago.bauermann/src/gcc/gcc/../include 
-I/home/thiago.bauermann/src/gcc/gcc/../libcpp/include
-I/home/thiago.bauermann/src/gcc/gcc/../libcody 
-I/home/thiago.bauermann/src/gcc/gcc/../libdecnumber
-I/home/thiago.bauermann/src/gcc/gcc/../libdecnumber/dpd -I../libdecnumber
-I/home/thiago.bauermann/src/gcc/gcc/../libbacktrace   -o ira.o -MT ira.o -MMD
-MP -MF ./.deps/ira.TPo /home/thiago.bauermann/src/gcc/gcc/ira.cc
during GIMPLE pass: slp
/home/thiago.bauermann/src/gcc/gcc/ira.cc: In function ‘void
setup_reg_class_relations()’:
/home/thiago.bauermann/src/gcc/gcc/ira.cc:1198:1: internal compiler error:
Floating point exception
 1198 | setup_reg_class_relations (void)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~
0x12ff9a5 crash_signal
        /home/thiago.bauermann/src/gcc/gcc/toplev.cc:314
0xf7a0d6df ???
        ../sysdeps/unix/sysv/linux/arm/sigrestorer.S:64
0xf79fdb05 ???
        ../sysdeps/unix/sysv/linux/arm/libc-do-syscall.S:46
0xf7a3d2c9 __pthread_kill_implementation
        ./nptl/pthread_kill.c:43
0xf7a0c83f __GI_raise
        ../sysdeps/posix/raise.c:26
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
make[3]: *** [Makefile:1181: ira.o] Error 1
make[3]: Leaving directory
'/home/thiago.bauermann/.cache/builds/gcc-native-aarch32/gcc'
make[2]: *** [Makefile:5150: all-stageprofile-gcc] Error 2
make[2]: Leaving directory
'/home/thiago.bauermann/.cache/builds/gcc-native-aarch32'
make[1]: *** [Makefile:26321: stageprofile-bubble] Error 2
make[1]: Leaving directory
'/home/thiago.bauermann/.cache/builds/gcc-native-aarch32'
make: *** [Makefile:1085: all] Error 2

I confirmed that the problem is still present in trunk as of commit
e029635cb72e "[modula2] Variable analysis understands DISPOSE and NIL" from
today.

I'm attaching the output of running with "-v -save-temps -freport-bug", as well
as the corresponding ira.ii.

Tested on Ubuntu 22.04 with:

$ src/gcc/configure \
    SHELL=/bin/bash \
    --with-gnu-as \
    --with-gnu-ld \
    --disable-libmudflap \
    --enable-lto \
    --enable-shared \
    --without-included-gettext \
    --enable-nls \
    --with-system-zlib \
    --disable-sjlj-exceptions \
    --enable-gnu-unique-object \
    --enable-linker-build-id \
    --disable-libstdcxx-pch \
    --enable-c99 \
    --enable-clocale=gnu \
    --enable-libstdcxx-debug \
    --enable-long-long \
    --with-cloog=no \
    --with-ppl=no \
    --with-isl=no \
    --disable-multilib \
    --with-float=hard \
    --with-fpu=neon-fp-armv8 \
    --with-mode=thumb \
    --with-arch=armv8-a \
    --enable-threads=posix \
    --enable-multiarch \
    --enable-libstdcxx-time=yes \
    --enable-gnu-indirect-function \
    --disable-werror \
    --enable-checking=yes \
    --enable-bootstrap \
    --enable-languages=c,c++,fortran,lto \
&& make profiledbootstrap \
        SHELL=/bin/bash \
        -w \
        -j 40 \
        CFLAGS_FOR_BUILD="-pipe -g -O2" \
        CXXFLAGS_FOR_BUILD="-pipe -g -O2" \
        LDFLAGS_FOR_BUILD="-static-libgcc" \
        MAKEINFOFLAGS=--force \
        BUILD_INFO="" \
        MAKEINFO=echo