New test, for spurious "variable may be clobbered by `longjmp' or `vfork'"

warnings.

From-SVN: r25765

gcc/testsuite/gcc.dg/setjmp-1.c

+/* Test for bogus "variable `x' may be clobbered by longjmp" warnings.
+   Inspired by cse.c:simplify_relational_operation. */
+
+/* { dg-do compile } */
+/* { dg-options "-O -W -Wall" } */
+
+#include <setjmp.h>
+
+extern void set_float_handler (jmp_buf *);
+
+#define EQ 0x01
+#define LT 0x02
+#define GT 0x04
+
+int
+compare_float (double a, double b)  /* { dg-bogus "clobbered" "spurious clobbered warning" { xfail *-*-* } } */
+{
+  jmp_buf handler;
+  int result;
+
+  a += 1.0;
+
+  if (setjmp (handler))
+    {
+      set_float_handler (0);
+      return 0;
+    }
+
+  set_float_handler (&handler);
+  if (a == b) result = EQ;
+  else if (a > b) result = LT;
+  else if (a < b) result = GT;
+  else result = 0;
+  set_float_handler (0);
+  return result;
+}