Move "X +- C1 CMP C2 to X CMP C2 -+ C1" to match.pd

Move "X +- C1 CMP C2 to X CMP C2 -+ C1" to match.pd

2016-05-02  Marc Glisse  <marc.glisse@inria.fr>

gcc/
	* flag-types.h (enum warn_strict_overflow_code): Move ...
	* coretypes.h: ... here.
	* fold-const.h (fold_overflow_warning): Declare.
	* fold-const.c (fold_overflow_warning): Make non-static.
	(fold_comparison): Move the transformation of X +- C1 CMP C2
	into X CMP C2 -+ C1 ...
	* match.pd: ... here.
	* gimple-fold.c (fold_stmt_1): Protect with
	fold_defer_overflow_warnings.

gcc/testsuite/
	* gcc.dg/tree-ssa/20040305-1.c: Adjust.

From-SVN: r235760