[Bug target/124696] New: [16 Regression] ICE: maximum number of generated reload insns per insn achieved (90) with -O -mno-sse2 -mstringop-strategy=loop --param=hot-bb-frequency-fraction=0

[zsojka at seznam dot cz via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124696

            Bug ID: 124696
           Summary: [16 Regression] ICE: maximum number of generated
                    reload insns per insn achieved (90) with -O -mno-sse2
                    -mstringop-strategy=loop
                    --param=hot-bb-frequency-fraction=0
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu

Created attachment 64082
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=64082&action=edit
reduced testcase

Compiler output:
$ x86_64-pc-linux-gnu-gcc -O -mno-sse2 -mstringop-strategy=loop
--param=hot-bb-frequency-fraction=0 testcase.c -Wno-psabi
during RTL pass: reload
testcase.c: In function 'foo':
testcase.c:15:1: internal compiler error: maximum number of generated reload
insns per insn achieved (90)
   15 | }
      | ^
0x2e80d0f internal_error(char const*, ...)
        /repo/gcc-trunk/gcc/diagnostic-global-context.cc:787
0x14af1d3 lra_constraints(bool)
        /repo/gcc-trunk/gcc/lra-constraints.cc:5701
0x148f7a4 lra(_IO_FILE*, int)
        /repo/gcc-trunk/gcc/lra.cc:2504
0x143622f do_reload
        /repo/gcc-trunk/gcc/ira.cc:6076
0x143622f execute
        /repo/gcc-trunk/gcc/ira.cc:6264
/repo/gcc-trunk/binary-trunk-20260330021621-r16-8325-g59c407c71a6648-checking-yes-rtl-df-extra-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/16.0.1/cc1
-quiet -iprefix
/repo/gcc-trunk/binary-trunk-20260330021621-r16-8325-g59c407c71a6648-checking-yes-rtl-df-extra-amd64/bin/../lib/gcc/x86_64-pc-linux-gnu/16.0.1/
testcase.c -quiet -dumpdir a- -dumpbase testcase.c -dumpbase-ext .c -mno-sse2
-mstringop-strategy=loop -mtune=generic -march=x86-64 -O -Wno-psabi
--param=hot-bb-frequency-fraction=0 -o /tmp/ccgmS9Cf.s
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.

$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-20260330021621-r16-8325-g59c407c71a6648-checking-yes-rtl-df-extra-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/16.0.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu
--target=x86_64-pc-linux-gnu --with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --enable-libsanitizer
--disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-20260330021621-r16-8325-g59c407c71a6648-checking-yes-rtl-df-extra-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 16.0.1 20260330 (experimental) (GCC)