PR tree-optimization/52904 testcase

[Kugan]

Hi,

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52904

Tescase was generating warning: assuming signed overflow does not occur
when simplifying conditional to constant [-Wstrict-overflow] due to VRP
missing the value range.

This seems to have been fixed and the PR is now closed. However, as
requested there in the PR, I am sending this patch to add the test-case
to test-suite.


Is this OK ?

Thanks,
Kugan

gcc/testsuite


2014-08-09  Kugan Vivekanandarajah  <kug...@linaro.org>

        PR tree-optimization/52904
        * gcc.dg/PR52904.c: New test.

diff --git a/gcc/testsuite/gcc.dg/PR52904.c b/gcc/testsuite/gcc.dg/PR52904.c
index e69de29..e490d23 100644
--- a/gcc/testsuite/gcc.dg/PR52904.c
+++ b/gcc/testsuite/gcc.dg/PR52904.c
@@ -0,0 +1,26 @@
+
+/* { dg-do compile } */
+/* { dg-options "-S -Wstrict-overflow -O2 -fdump-tree-vrp2" } */
+
+extern int foo (int);
+
+
+int
+wait_reading_process_output (void)
+{
+  int nfds = 0;
+  int channel;
+  for (channel = 0; channel < 1024; ++channel)
+    {
+      if (foo (channel))
+       nfds++;
+    }
+  if (nfds < 0)
+    return 1;
+  return 0;
+}
+
+/* { dg-bogus "assuming signed overflow does not occur when simplifying\
+   conditional to constant" */
+/* { dg-final { scan-tree-dump "\\\[0, 1023\\\]" "vrp2" } } */
+/* { dg-final { cleanup-tree-dump "vrp2" } } */