re PR target/46254 (ICE: in find_reloads, at reload.c:3806 (unable to generate reloads) with -fPIC -mcmodel={medium|large} and __sync_val_compare_and_swap)

	PR target/46254
	* config/i386/predicates.md (cmpxchg8b_pic_memory_operand): Return
	true for TARGET_64BIT or !flag_pic.
	* config/i386/sync.md (*atomic_compare_and_swap_doubledi_pic): Remove.
	(atomic_compare_and_swap_double<mode>): Change operand 2 predicate
	to cmpxchg8b_pic_memory_operand.  Use DWIH mode iterator.
	Add insn constraint.  Conditionally emit xchg asm insns.
	(atomic_compare_and_swap<mode>): Update calls.  Check only
	cmpxchg8b_pic_memory_operand in memory address fixup.
	(DCASMODE): Remove.
	(CASHMODE): Rename from DCASHMODE.
	(doublemodesuffix): Update modes.
	(regprefix): New mode attribute.

	(unspecv) <UNSPECV_CMPXCHG_{1,2,3,4}>: Remove.
	<UNSPECV_CMPXCHG>: New constant.
	(atomic_compare_and_swap<mode>_1): Rename from
	atomic_compare_and_swap_single<mode>.  Update calls and
	unspec_volatile constants.
	(atomic_compare_and_swap<mode>_doubleword): Rename from
	atomic_compare_and_swap_double<mode>.  Update calls and
	unspec_volatile constants.

testsuite/ChangeLog:

	PR target/46254
	* gcc.target/i386/pr46254.c: New test.

From-SVN: r190732