"SYNC",
	"XOR",
	"XORCC",
	"XORIS",
	"DCBF",
	"DCBI",
	"DCBST",
	"DCBT",
	"DCBTST",
	"DCBZ",
	"EIEIO",
	"ICBI",
	"ISYNC",
	"PTESYNC",
	"TLBIE",
	"TLBIEL",
	"TLBSYNC",
	"TW",
	"SYSCALL",
	"WORD",
	"RFCI",
	"FCPSGN",
	"FCPSGNCC",
	"FRES",
	"FRESCC",
	"FRIM",
	"FRIMCC",
	"FRIP",
	"FRIPCC",
	"FRIZ",
	"FRIZCC",
	"FRIN",
	"FRINCC",

//	} else
//		return 0;
TEXT ·Cas(SB), NOSPLIT, $0-17
	MOVD	ptr+0(FP), R3
	MOVWZ	old+8(FP), R4
	MOVWZ	new+12(FP), R5
	LWSYNC
cas_again:
	LWAR	(R3), R6
	CMPW	R6, R4
	BNE	cas_fail
	STWCCC	R5, (R3)
	BNE	cas_again
	MOVD	$1, R3
	LWSYNC
	MOVB	R3, ret+16(FP)
	RET
cas_fail:
	LWSYNC
	MOVB	R0, ret+16(FP)
	RET

// bool	·Cas64(uint64 *ptr, uint64 old, uint64 new)
// Atomically:
//	if(*val == old){