Hi!
expand_omp_for_init_counts was using for the case where collapse(2)
inner loop has init expression dependent on non-constant multiple of
the outer iterator and the condition upper bound expression doesn't
depend on the outer iterator fold_unary (NEGATE_EXPR, ...). This
will just return NULL if it can't be folded, we need fold_build1
instead.
Bootstrapped/regtested on x86_64-linux and i686-linux, committed to trunk.
2023-01-19 Jakub Jelinek <ja...@redhat.com>
PR middle-end/108459
* omp-expand.cc (expand_omp_for_init_counts): Use fold_build1 rather
than fold_unary for NEGATE_EXPR.
* testsuite/libgomp.c/pr108459.c: New test.
--- gcc/omp-expand.cc.jj 2023-01-02 09:32:49.399894958 +0100
+++ gcc/omp-expand.cc 2023-01-19 12:01:05.103410564 +0100
@@ -2003,8 +2003,8 @@ expand_omp_for_init_counts (struct omp_f
t = fold_build2 (MINUS_EXPR, itype, unshare_expr (fd->loops[i].m2),
unshare_expr (fd->loops[i].m1));
else if (fd->loops[i].m1)
- t = fold_unary (NEGATE_EXPR, itype,
- unshare_expr (fd->loops[i].m1));
+ t = fold_build1 (NEGATE_EXPR, itype,
+ unshare_expr (fd->loops[i].m1));
else
t = unshare_expr (fd->loops[i].m2);
tree m2minusm1
--- libgomp/testsuite/libgomp.c/pr108459.c.jj 2023-01-19 12:22:07.191038771
+0100
+++ libgomp/testsuite/libgomp.c/pr108459.c 2023-01-19 12:21:17.973755215
+0100
@@ -0,0 +1,41 @@
+/* PR middle-end/108459 */
+
+char a[17][17];
+
+__attribute__((noipa)) void
+foo (int x, int y)
+{
+ #pragma omp for collapse(2)
+ for (int i = 1; i <= 16; i++)
+ for (int j = i * x + y; j <= 16; j++)
+ a[i][j] = 1;
+}
+
+int
+main ()
+{
+ #pragma omp parallel
+ foo (1, 1);
+ for (int i = 0; i <= 16; i++)
+ for (int j = 0; j <= 16; j++)
+ if (i >= 1 && j >= i + 1)
+ {
+ if (a[i][j] != 1)
+ __builtin_abort ();
+ a[i][j] = 0;
+ }
+ else if (a[i][j])
+ __builtin_abort ();
+ #pragma omp parallel
+ foo (2, -2);
+ for (int i = 0; i <= 16; i++)
+ for (int j = 0; j <= 16; j++)
+ if (i >= 1 && j >= 2 * i - 2)
+ {
+ if (a[i][j] != 1)
+ __builtin_abort ();
+ }
+ else if (a[i][j])
+ __builtin_abort ();
+ return 0;
+}
Jakub
