re PR target/65697 (__atomic memory barriers not strong enough for __sync builtins)

[gcc.git] / gcc / tree-vrp.c

diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index fdaebe4c2fc37a52251f05a6dd67c8c435c326f6..ec6d2c3e139ee9ddf2c0e3041a6be4a4fc4eb2d4 100644 (file)
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -3133,14 +3133,33 @@ extract_range_from_binary_expr_1 (value_range_t *vr,
                 and all numbers from min to 0 for negative min.  */
              cmp = compare_values (vr0.max, zero);
              if (cmp == -1)
-               max = zero;
+               {
+                 /* When vr0.max < 0, vr1.min != 0 and value
+                    ranges for dividend and divisor are available.  */
+                 if (vr1.type == VR_RANGE
+                     && !symbolic_range_p (&vr0)
+                     && !symbolic_range_p (&vr1)
+                     && !compare_values (vr1.min, zero))
+                   max = int_const_binop (code, vr0.max, vr1.min);
+                 else
+                   max = zero;
+               }
              else if (cmp == 0 || cmp == 1)
                max = vr0.max;
              else
                type = VR_VARYING;
              cmp = compare_values (vr0.min, zero);
              if (cmp == 1)
-               min = zero;
+               {
+                 /* For unsigned division when value ranges for dividend
+                    and divisor are available.  */
+                 if (vr1.type == VR_RANGE
+                     && !symbolic_range_p (&vr0)
+                     && !symbolic_range_p (&vr1))
+                   min = int_const_binop (code, vr0.min, vr1.max);
+                 else
+                   min = zero;
+               }
              else if (cmp == 0 || cmp == -1)
                min = vr0.min;
              else