PR target/52076
	* config/m68k/m68k.md (xorsi3_internal): Twiddle constraints to
	improve code density for small immediate to memory case.
	(insv): Better handle bitfield assignments when the field is
	being set to all ones.
	* config/m68k/predicates.md (reg_or_pow2_m1_operand): New
	operand predicate.

	PR target/52076
	* gcc.target/m68k/pr52076-1.c: New test.
	* gcc.target/m68k/pr52076-2.c: New test.

From-SVN: r220015