#define rAX	0
#define rCX	1
#define rDX	2
#define rBX	3
#define rSP	4
#define rBP	5
#define rSI	6
#define rDI	7

#define rX0	0
#define rX1	1
#define rX2	2
#define rX3	3
#define rX4	4
#define rX5	5
#define rX6	6

#define OP(o, m, ro, rm)	WORD $0x0F66;	/* op + modr/m byte */	\
			BYTE $(o);					\
			BYTE $(((m)<<6)|((ro)<<3)|(rm))
#define OPi(o, m, ro, rm, i)	OP((o), (m), (ro), (rm));		\
			BYTE $(i)
#define OP4(o, m, ro, rm)	WORD $0x0F66;				\
			WORD $(o);					\
			BYTE $(((m)<<6)|((ro)<<3)|(rm))
#define OP4i(o, m, ro, rm, i)	OP4((o), (m), (ro), (rm));		\
			BYTE $(i)

/* MOVLPD */
//opcode = 660F12
//modrm  = 01 000 000 [AX → X0] / 01 001 000 [AX → X1]
//disp8 = 8 / 32
#define MOVLPD(off, s, d) OPi(0x12, 0x1, (d), (s), (off))

/* MOVHPD */
//opcode = 660F16
//modrm  = 01 000 000 [AX → X0] / 01 001 000 [AX → X1]
//disp8 = 16 / 40
#define MOVHPD(off, s, d) OPi(0x16, 0x1, (d), (s), (off))

/* HSUBPD */
//opcode = 660F7D = 01100110 00001111 01111101
//modrm = 11 000 000 [X0 → X0]
#define HSUBPD(s, d) OP(0x7D, 0x3, (d), (s))

/* DPPD */
//opcode = 660F3A41 = 01100110 00001111 00111010 01000001
//modrm  = 11 000 001 [X1 → X0]
//imm8   = 0011 0001
#define DPPD(s, d) OP4i(0x413A, 0x3, (d), (s), 0x31)