This adds a testcase for the fixed PR, VN now gets us the transform
via IV equality plus predication.
Pushed.
2022-01-12 Richard Biener <rguent...@suse.de>
PR tree-optimization/76174
* gcc.dg/tree-ssa/pr76174.c: New testcase.
---
gcc/testsuite/gcc.dg/tree-ssa/pr76174.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr76174.c
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr76174.c
b/gcc/testsuite/gcc.dg/tree-ssa/pr76174.c
new file mode 100644
index 00000000000..17a4a0faf24
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr76174.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-cddce1" } */
+
+void foo();
+
+void l(unsigned int r) {
+ unsigned int q = 0;
+ unsigned int c = r;
+ for (unsigned int x = 0; x<r; x++) {
+ if (q == c) {
+ foo();
+ c *= 2;
+ }
+ q++;
+ }
+}
+
+/* We should be able to elide the body of the function by means of
+ figuring out the equality between the two IVs and then simplifying
+ the q == c test. */
+/* { dg-final { scan-tree-dump-not "foo" "cddce1" } } */
+/* { dg-final { scan-tree-dump-times "bb" 1 "cddce1" } } */
--
2.31.1
