[Bug target/123094] New: [15 Regression] AArch64 armv9-a: ICE at -O2 during RTL pass: cse2

[xxs_chy at outlook dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123094

            Bug ID: 123094
           Summary: [15 Regression] AArch64 armv9-a: ICE at -O2 during RTL
                    pass: cse2
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: xxs_chy at outlook dot com
  Target Milestone: ---

Created attachment 63035
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=63035&action=edit
test.c

Reproducer: https://godbolt.org/z/99aceE44K

Testcase is attached.

command:
> aarch64-unknown-linux-musl-gcc -march=armv9-a -O2 test.c

GCC dump:
during RTL pass: cse2
<source>: In function 'backsmith_pure_5':
<source>:101:1: internal compiler error: in insert_regs, at cse.cc:1114
  101 | }
      | ^
0x7157a5029e3f __libc_start_main
        ???:0
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Compiler returned: 1