[Bug middle-end/120276] New: [16 Regression] ICE in partial_subreg_p with SVE

[ktkachov at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120276

            Bug ID: 120276
           Summary: [16 Regression] ICE in partial_subreg_p with SVE
           Product: gcc
           Version: 15.0
            Status: UNCONFIRMED
          Keywords: aarch64-sve, ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ktkachov at gcc dot gnu.org
  Target Milestone: ---
            Target: aarch64

int a;
char b[1];
int c[18];
void d(char *);
void e() {
  int f;
  char *g;
  a = 0;
  for (; a < 18; a++) {
    int h = f = 0;
    for (; f < 4; f++) {
      g[a * 4 + f] = c[a] >> h;
      h += 8;
    }
  }
  d(b);
} 

ICEs on aarch64 with e.g. -O3 -march=armv8.2-a+sve
during RTL pass: cprop_hardreg
ice.c: In function ‘e’:
ice.c:17:1: internal compiler error: in partial_subreg_p, at rtl.h:3203
   17 | }
      | ^
0x239032b internal_error(char const*, ...)
        $SRC/gcc/diagnostic-global-context.cc:517
0x8282ff fancy_abort(char const*, int, char const*)
        $SRC/gcc/diagnostic.cc:1815
0x806df3 partial_subreg_p(machine_mode, machine_mode)
        $SRC/gcc/rtl.h:3203
0xf8e807 partial_subreg_p(machine_mode, machine_mode)
        $SRC/gcc/poly-int.h:1365
0xf8e807 copy_value
        $SRC/gcc/regcprop.cc:374
0xf8eff3 copyprop_hardreg_forward_1
        $SRC/gcc/regcprop.cc:1153
0xf8f9d3 execute
        $SRC/gcc/regcprop.cc:1423
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