gcc/testsuite/gcc.dg/pr98420.c - gcc - Git at Google

 /* { dg-do compile } */
 /* { dg-options "-O2 -ffinite-math-only -frounding-math -fdump-tree-optimized" } */
 double foo (double a)
 {
   return a - a;
 }

 /* { dg-final { scan-tree-dump " = a_\[0-9\]\\(D\\) - a_\[0-9\]\\(D\\);" "optimized" } } */
	/* { dg-do compile } */
	/* { dg-options "-O2 -ffinite-math-only -frounding-math -fdump-tree-optimized" } */
	double foo (double a)
	{
	return a - a;
	}

	/* { dg-final { scan-tree-dump " = a_\[0-9\]\\(D\\) - a_\[0-9\]\\(D\\);" "optimized" } } */