Invalid code generated by Powerpc64 -O1, -Oz

[godjhh]

Proof of Concepts

#include <stdint.h>
#include <stdio.h>
struct {
  signed a;
} b = {-1L};
int32_t c;
uint64_t d;
uint8_t e[];
int32_t **h(int32_t **, int64_t);
static int32_t **f(uint32_t, int16_t);
int64_t g() {
  int32_t *k = &b;
  h(f((*k < 1) == *k, *k), *k);
}
int32_t **h(int32_t **, int64_t i) { d = i > 0 ^ i; }
int32_t **f(uint32_t l, int16_t j) {
  if (j || (e[0] = 0), c || l | -1L <= j)
    ;
  else
    for (;;)
      ;
}
int main() {
  g();
  printf("%lu\n", d);
  return 0;
}

godbolt link: https://www.godbolt.org/z/9xKG5Tac6

[dtcxzyw]

Could you please clarify your issue? Is it a miscompilation?

[godjhh]

Could you please clarify your issue? Is it a miscompilation?

Invalid value output from optimization level -O1, -Oz.

Normal output(O0, O2, O3, Os): 18446744073709551615
Abnormal output(O1, Oz): 18446744073709551614

[llvmbot]

@llvm/issue-subscribers-backend-powerpc

Author: godjhh (godjhh)

### Proof of Concepts ``` #include <stdint.h> #include <stdio.h> struct { signed a; } b = {-1L}; int32_t c; uint64_t d; uint8_t e[]; int32_t **h(int32_t **, int64_t); static int32_t **f(uint32_t, int16_t); int64_t g() { int32_t *k = &b; h(f((*k < 1) == *k, *k), *k); } int32_t **h(int32_t **, int64_t i) { d = i > 0 ^ i; } int32_t **f(uint32_t l, int16_t j) { if (j || (e[0] = 0), c || l | -1L <= j) ; else for (;;) ; } int main() { g(); printf("%lu\n", d); return 0; } ```

godbolt link: https://www.godbolt.org/z/9xKG5Tac6

[nemanjai]

This seems like some kind of generated test case. Have you confirmed that it is free from UB? Also can you comment on what code/project this affects?

[chenzheng1030]

This seems like some kind of generated test case. Have you confirmed that it is free from UB?

Verified with -fsanitize=address and -fsanitize=undefined, the case is OK.

The issue can be reproduced on AIX 64 with -mcpu=pwr8 or above. It is OK with -mcpu=pwr7.

[chenzheng1030]

Sorry for the late. I posted #84419 for this miscompile