MOVQ	DX, X2 // X2 = sign bit mask
	CVTTSD2SQ	X0, AX
	ANDNPD	X0, X2 // X2 = sign
	CVTSQ2SD	AX, X1	// X1 = float(int(x))
	CMPSD	X1, X0, 2 // compare LE; X0 = 0xffffffffffffffff or 0
	ORPD	X2, X1 // if X1 = 0.0, incorporate sign
	MOVSD	$1.0, X3
	ANDNPD	X3, X0
	ORPD	X2, X0 // if float(int(x)) <= x {X0 = 1} else {X0 = -0}
	ADDSD	X1, X0
	MOVSD	X0, ret+8(FP)
	RET
isBig_ceil:
	MOVQ	AX, ret+8(FP)
	RET

// func archTrunc(x float64) float64

	CMPQ    AX, BX
	JLE     isInfOrNaN
	// f1, ki := math.Frexp(x); k := float64(ki)
	MOVQ    BX, X0
	MOVQ    $0x000FFFFFFFFFFFFF, AX
	MOVQ    AX, X2
	ANDPD   X0, X2
	MOVSD   $0.5, X0 // 0x3FE0000000000000
	ORPD    X0, X2 // X2= f1
	SHRQ    $52, BX
	ANDL    $0x7FF, BX
	SUBL    $0x3FE, BX
	XORPS   X1, X1 // break dependency for CVTSL2SD
	CVTSL2SD BX, X1 // x1= k, x2= f1
	// if f1 < math.Sqrt2/2 { k -= 1; f1 *= 2 }

	"MULSS",
	"MULW",
	"MULXL",
	"MULXQ",
	"MWAIT",
	"NEGB",
	"NEGL",
	"NEGQ",
	"NEGW",
	"NOPL",
	"NOPW",
	"NOTB",
	"NOTL",
	"NOTQ",
	"NOTW",
	"ORB",
	"ORL",
	"ORPD",
	"ORPS",
	"ORQ",
	"ORW",
	"OUTB",
	"OUTL",
	"OUTSB",
	"OUTSL",
	"OUTSW",
	"OUTW",
	"PABSB",
	"PABSD",
	"PABSW",
	"PACKSSLW",
	"PACKSSWB",
	"PACKUSDW",
	"PACKUSWB",

	ORB (R11), R11                          // 450a1b
	ORPD (BX), X2                           // 660f5613
	ORPD (R11), X2                          // 66410f5613
	ORPD X2, X2                             // 660f56d2
	ORPD X11, X2                            // 66410f56d3
	ORPD (BX), X11                          // 66440f561b
	ORPD (R11), X11                         // 66450f561b
	ORPD X2, X11                            // 66440f56da

	MULSD:           "MULSD",
	MULSS:           "MULSS",
	MWAIT:           "MWAIT",
	NEG:             "NEG",
	NOP:             "NOP",
	NOT:             "NOT",
	OR:              "OR",
	ORPD:            "ORPD",
	ORPS:            "ORPS",
	OUT:             "OUT",
	OUTSB:           "OUTSB",
	OUTSD:           "OUTSD",
	OUTSW:           "OUTSW",
	PABSB:           "PABSB",
	PABSD:           "PABSD",