[Bug target/123390] New: UBSAN: arm: gcc/config/arm/arm.cc:5435:48: runtime error: signed integer overflow: -2147483648 - 1 cannot be represented in type 'int'

[dcb314 at hotmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123390

            Bug ID: 123390
           Summary: UBSAN: arm: gcc/config/arm/arm.cc:5435:48: runtime
                    error: signed integer overflow: -2147483648 - 1 cannot
                    be represented in type 'int'
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

I get the line in the title from a bootstrap
of current trunk gcc on arm raspberry PI 5.

The line of code is

      && (remainder & ((1 << set_zero_bit_copies) - 1)) == remainder)

and the configure command is

CFLAGS="-g1 -O2 -march=native" \
CXXFLAGS="-g1 -O2 -march=native" \
../trunk/configure  \
    --disable-doc \
    --disable-multilib \
    --with-build-config="bootstrap-ubsan" \
    --enable-checking=yes \
    --enable-languages=c,c++ \
    --with-cpu=cortex-a76 \
    --with-fpu=neon-fp-armv8 \
    --with-float=hard \
    --build=arm-linux-gnueabihf \
    --host=arm-linux-gnueabihf \
    --target=arm-linux-gnueabihf

git blame says:

^4ef521bbc6 (Jason Merrill            2022-12-14 17:42:52 -0500  5435)    &&
(remainder & ((1 << set_zero_bit_copies) - 1)) == remainder)