* [committed] vrp: Fix operator_trunc_mod::op1_range [PR97888]
@ 2020-11-18 21:20 Jakub Jelinek
0 siblings, 0 replies; only message in thread
From: Jakub Jelinek @ 2020-11-18 21:20 UTC (permalink / raw)
To: gcc-patches
Hi!
As mentioned in the PR, in (x % y) >= 0 && y >= 0, we can't deduce
x's range to be x >= 0, as e.g. -7 % 7 is 0. But we can deduce it
from (x % y) > 0. The patch also fixes up the comments.
Bootstrapped/regtested on x86_64-linux and i686-linux, preapproved in the PR
by Andrew, committed to trunk.
2020-11-18 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/91029
PR tree-optimization/97888
* range-op.cc (operator_trunc_mod::op1_range): Only set op1
range to >= 0 if lhs is > 0, rather than >= 0. Fix up comments.
* gcc.dg/pr91029.c: Add comment with PR number.
(f2): Use > 0 rather than >= 0.
* gcc.c-torture/execute/pr97888-1.c: New test.
* gcc.c-torture/execute/pr97888-2.c: New test.
--- gcc/range-op.cc.jj 2020-11-18 09:40:09.732661752 +0100
+++ gcc/range-op.cc 2020-11-18 11:19:25.322812925 +0100
@@ -2692,13 +2692,13 @@ operator_trunc_mod::op1_range (irange &r
if (TYPE_SIGN (type) == SIGNED && wi::ge_p (op2.lower_bound (), 0, SIGNED))
{
unsigned prec = TYPE_PRECISION (type);
- // if a & b >=0 , then a >= 0.
- if (wi::ge_p (lhs.lower_bound (), 0, SIGNED))
+ // if a % b > 0 , then a >= 0.
+ if (wi::gt_p (lhs.lower_bound (), 0, SIGNED))
{
r = value_range (type, wi::zero (prec), wi::max_value (prec, SIGNED));
return true;
}
- // if a & b < 0 , then a <= 0.
+ // if a % b < 0 , then a <= 0.
if (wi::lt_p (lhs.upper_bound (), 0, SIGNED))
{
r = value_range (type, wi::min_value (prec, SIGNED), wi::zero (prec));
--- gcc/testsuite/gcc.dg/pr91029.c.jj 2020-11-18 11:21:25.412447195 +0100
+++ gcc/testsuite/gcc.dg/pr91029.c 2020-11-18 11:22:08.391958411 +0100
@@ -1,3 +1,4 @@
+/* PR tree-optimization/91029 */
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-evrp" } */
@@ -16,7 +17,7 @@ void f1 (int i)
void f2 (int i)
{
- if ((i % 7) >= 0)
+ if ((i % 7) > 0)
{
xx = (i < 0);
if (xx)
--- gcc/testsuite/gcc.c-torture/execute/pr97888-1.c.jj 2020-11-18 11:29:22.017027013 +0100
+++ gcc/testsuite/gcc.c-torture/execute/pr97888-1.c 2020-11-18 11:28:47.131423750 +0100
@@ -0,0 +1,24 @@
+/* PR tree-optimization/97888 */
+
+int a = 1, c = 4, d, e;
+
+int
+main ()
+{
+ int f = -173;
+ int b;
+ for (b = 0; b < 10; b++)
+ {
+ int g = f % (~0 && a), h = 0, i = 0;
+ if (g)
+ __builtin_unreachable ();
+ if (c)
+ h = f;
+ if (h > -173)
+ e = d / i;
+ f = h;
+ }
+ if (f != -173)
+ __builtin_abort ();
+ return 0;
+}
--- gcc/testsuite/gcc.c-torture/execute/pr97888-2.c.jj 2020-11-18 11:29:24.956993572 +0100
+++ gcc/testsuite/gcc.c-torture/execute/pr97888-2.c 2020-11-18 11:29:12.543134760 +0100
@@ -0,0 +1,19 @@
+/* PR tree-optimization/97888 */
+
+__attribute__((noipa)) void
+foo (int i)
+{
+ if ((i % 7) >= 0)
+ {
+ if (i >= 0)
+ __builtin_abort ();
+ }
+}
+
+int
+main ()
+{
+ foo (-7);
+ foo (-21);
+ return 0;
+}
Jakub
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