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-rw-r--r--gcc-4.9/gcc/testsuite/gcc.dg/tree-ssa/pr19210-2.c29
1 files changed, 29 insertions, 0 deletions
diff --git a/gcc-4.9/gcc/testsuite/gcc.dg/tree-ssa/pr19210-2.c b/gcc-4.9/gcc/testsuite/gcc.dg/tree-ssa/pr19210-2.c
new file mode 100644
index 000000000..9116e97ec
--- /dev/null
+++ b/gcc-4.9/gcc/testsuite/gcc.dg/tree-ssa/pr19210-2.c
@@ -0,0 +1,29 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -funsafe-loop-optimizations -Wunsafe-loop-optimizations" } */
+extern void g(void);
+
+void
+f (unsigned n)
+{
+ unsigned k;
+ for(k = 0;k <= n;k++) /* { dg-warning "assuming.*not infinite" } */
+ g();
+
+ for(k = 5;k <= n;k += 4) /* { dg-warning "assuming.*not overflow" } */
+ g();
+
+ /* We used to get warning for this loop. However, since then # of iterations
+ analysis improved, and we can now prove that this loop does not verflow.
+ This is because the only case when it would overflow is if n = ~0 (since
+ ~0 is divisible by 5), and this cannot be the case, since when we got
+ here, the previous loop exited, thus there exists k > n. */
+ for(k = 5;k <= n;k += 5)
+ g();
+
+ for(k = 4;k <= n;k += 5) /* { dg-warning "assuming.*not overflow" } */
+ g();
+
+ for(k = 15;k >= n;k--) /* { dg-warning "assuming.*not infinite" } */
+ g();
+
+}