instructions["JPO"] = x86.AJPC  /* alternate */
	instructions["JPS"] = x86.AJPS  /* parity set (PF = 1) */
	instructions["JS"] = x86.AJMI   /* alternate */
	instructions["JZ"] = x86.AJEQ   /* alternate */
	instructions["MASKMOVDQU"] = x86.AMASKMOVOU
	instructions["MOVD"] = x86.AMOVQ
	instructions["MOVDQ2Q"] = x86.AMOVQ
	instructions["MOVNTDQ"] = x86.AMOVNTO
	instructions["MOVOA"] = x86.AMOVO

<pre>
// uint64 atomicload64(uint64 volatile* addr);
// so actually
// void atomicload64(uint64 *res, uint64 volatile *addr);
TEXT runtime·atomicload64(SB), NOSPLIT, $0-12
	MOVL	ptr+0(FP), AX
	TESTL	$7, AX
	JZ	2(PC)
	MOVL	0, AX // crash with nil ptr deref
	LEAL	ret_lo+4(FP), BX
	// MOVQ (%EAX), %MM0
	BYTE $0x0f; BYTE $0x6f; BYTE $0x00
	// MOVQ %MM0, 0(%EBX)
	BYTE $0x0f; BYTE $0x7f; BYTE $0x03
	// EMMS