re PR tree-optimization/91734 (gcc skip an if statement with "-O1 -ffast-math")

re PR tree-optimization/91734 (gcc skip an if statement  with "-O1 -ffast-math")

	PR tree-optimization/91734
	* generic-match-head.c: Include fold-const-call.h.
	* match.pd (sqrt(x) cmp c): Check the boundary value and
	in case inexact computation of c*c affects comparison of the boundary,
	turn LT_EXPR into LE_EXPR, GE_EXPR into GT_EXPR, LE_EXPR into LT_EXPR
	or GT_EXPR into GE_EXPR.  Punt for sqrt comparisons against NaN and
	for -frounding-math.  For c2, try the next smaller or larger floating
	point constant depending on comparison code and if it has the same
	sqrt as c2, use it instead of c2.

	* gcc.dg/pr91734.c: New test.

From-SVN: r276621