[Bug target/122448] [15/16 Regression] Wrong rvv code with -O3

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122448

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[15 16 Regression] Wrong    |[15/16 Regression] Wrong
                   |rvv code with -O3           |rvv code with -O3
   Target Milestone|---                         |15.3

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
Does not reproduce with the following (separated the vectorized loop). 
Vectorization still happens.  The bug reproduces when noipa but kept m() and
mm() in a single function.  I suspect sth wrong with the riscv intrinsics
or interaction with those and the vector code (setvl missing for the
intrinsics,
wrongly re-used from vector code?).

#include <riscv_vector.h>
int a;
long b = -2260814313524985651LL;
short c; char d;
short e[576];
unsigned long long f;
void g(unsigned long long *i, unsigned long long ad) { *i = ad; }
int8_t j[4];
int16_t k[4], l[4];
void __attribute__((noipa)) m() {
  for (short n = 1; n < 023; n += 4)
    for (short o = 0; o < static_cast<short>(1033314678U); o += 4)
      for (int p = (int)((long long)(b - 859406540) & 0xFFFFFFFF); p < 9; p +=
3) {
        c ^= static_cast<short>(1033314678 % 0x10000);
        d &= static_cast<char>(a ? 0 : e[p * 24]);
      }
}
void mm() {
  for (bool q = 0; q < (bool)8; q = 1) {
    size_t r = 4;
    for (size_t v; r; r -= v) {
      v = __riscv_vsetvl_e16m1(r);
      vint8mf2_t w = __riscv_vle8_v_i8mf2(&j[0], v);
      vbool16_t ac = __riscv_vmseq_vx_i8mf2_b16(w, 1, v);
      vint16m1_t x = __riscv_vmv_v_x_i16m1(0, __riscv_vsetvlmax_e16m1());
      vuint16m1_t y = __riscv_vsll_vx_u16m1(__riscv_vid_v_u16m1(v), 1, v);
      vint16m1_t z = __riscv_vluxei16_v_i16m1_tu(x, &k[0], y, v);
      vint16m1_t aa = __riscv_vmax_vv_i16m1(z, z, v);
      vuint8mf2_t ab = __riscv_vsll_vx_u8mf2(__riscv_vid_v_u8mf2(v), 1, v);
      __riscv_vsoxei8_v_i16m1_m(ac, &l[0], ab, aa, v);
    }
  }
}
int main() {
  m();
  mm();
  g(&f, d);
  __builtin_printf("%llu\n", f);
}