re PR tree-optimization/66974 (-Warray-bounds false positive with -O3)

2017-12-14  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/66974
	* gcc.dg/Warray-bounds-24.c: New testcase.

From-SVN: r255642

gcc/testsuite/ChangeLog

 2017-12-14  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/66974
+	* gcc.dg/Warray-bounds-24.c: New testcase.
+
+2017-12-14  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/65258
 	* gcc.dg/Warray-bounds-23.c: New testcase.
 

gcc/testsuite/gcc.dg/Warray-bounds-24.c

+/* { dg-do compile } */
+/* { dg-options "-O3 -Warray-bounds" } */
+
+int foo(unsigned order)
+{
+  int c[3] = {1, 2, 3};
+  unsigned i, j;
+  for (i = 1; i < order; i++) {
+      for (j = 0; j < i / 2; j++) {
+	  c[j] += c[i] * c[i-j-1]; /* { dg-bogus "array bounds" } */
+	  c[i-j-1] += c[i] * c[j]; /* { dg-bogus "array bounds" } */
+      }
+  }
+  return c[0];
+}