re PR tree-optimization/45216 (Rotate expressions not recognized at tree level)

re PR tree-optimization/45216 (Rotate expressions not recognized at tree level)

	PR tree-optimization/45216
	PR tree-optimization/57157
	* tree-ssa-forwprop.c (simplify_rotate): Only recognize
	the (-Y) & (B - 1) variant if OP is |.
	* expmed.c (expand_shift_1): For rotations by const0_rtx just
	return shifted.  Use (-op1) & (prec - 1) as other_amount
	instead of prec - op1.

	* c-c++-common/rotate-1.c: Add 32 tests with +.
	* c-c++-common/rotate-1a.c: Adjust.
	* c-c++-common/rotate-2.c: Add 32 tests with +, expect
	only 48 rotates.
	* c-c++-common/rotate-2b.c: New test.
	* c-c++-common/rotate-3.c: Add 32 tests with +.
	* c-c++-common/rotate-4.c: Add 32 tests with +, expect
	only 48 rotates.
	* c-c++-common/rotate-4b.c: New test.
	* c-c++-common/rotate-5.c: New test.

From-SVN: r198823