[Bug tree-optimization/102622] [12 Regression] Wrong code with -O3 for skylake-avx512 and icelake-server by r12-3903

pinskia at gcc dot gnu.org gcc-bugzilla@gcc.gnu.org
Fri Oct 8 06:04:48 GMT 2021


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102622

--- Comment #15 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
here is the C testcase:
static inline const unsigned *max1(const unsigned *t, const unsigned *t1)
{
    return *t > *t1 ? t : t1;
}
int var_20 = 0;
int var_22 = 0;
short arr_32 [13];
char arr_45 [69];
void test(int a, unsigned b, const long long *c) __attribute__((noipa));
void test(int a, unsigned b, const long long *c) {
  for (short d = 0; d < 13; d++) {
    for (int e = 0; e < a; e += 3)
      var_20 = 0;
    unsigned t = (short)b;
    if (*max1(&b, &t)) {
      arr_32[d] = 0;
      var_22 = *c;
    }
    for (unsigned f = 0; f < 69; f += 4)
      arr_45[f] = 0;
  }
}

int main() {
    long long t = 42;
    test(-1, 1, &t);
    if (var_22 != 42)
      __builtin_abort();
    return 0;
}

---- CUT -----

Here is the patch which I tested and is working:
diff --git a/gcc/match.pd b/gcc/match.pd
index a9791ceb74a..4fd2a8c3ea9 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3950,10 +3950,12 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
     (if (integer_onep (@1))
      (convert (convert:boolean_type_node @0)))
     /* a ? -1 : 0 -> -a. */
-    (if (INTEGRAL_TYPE_P (type) && integer_all_onesp (@1))
+    (if (INTEGRAL_TYPE_P (type) && integer_all_onesp (@1)
+         && TYPE_PRECISION (type) != 1)
      (negate (convert (convert:boolean_type_node @0))))
     /* a ? powerof2cst : 0 -> a << (log2(powerof2cst)) */
-    (if (INTEGRAL_TYPE_P (type) && integer_pow2p (@1))
+    (if (INTEGRAL_TYPE_P (type) && integer_pow2p (@1)
+         && TYPE_PRECISION (type) != 1)
      (with {
        tree shift = build_int_cst (integer_type_node, tree_log2 (@1));
       }
@@ -3967,10 +3969,12 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
      (if (integer_onep (@2))
       (convert (bit_xor (convert:boolean_type_node @0) { booltrue; } )))
      /* a ? -1 : 0 -> -(!a). */
-     (if (INTEGRAL_TYPE_P (type) && integer_all_onesp (@2))
+     (if (INTEGRAL_TYPE_P (type) && integer_all_onesp (@2)
+         && TYPE_PRECISION (type) != 1)
       (negate (convert (bit_xor (convert:boolean_type_node @0) { booltrue; }
))))
      /* a ? powerof2cst : 0 -> (!a) << (log2(powerof2cst)) */
-     (if (INTEGRAL_TYPE_P (type) &&  integer_pow2p (@2))
+     (if (INTEGRAL_TYPE_P (type) &&  integer_pow2p (@2)
+         && TYPE_PRECISION (type) != 1)
       (with {
        tree shift = build_int_cst (integer_type_node, tree_log2 (@2));
        }


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