// Copyright 2012 The Go Authors. All rights reserved.

// Use of this source code is governed by a BSD-style

// license that can be found in the LICENSE file.

#include "textflag.h"

#define Big 0x4330000000000000 // 2**52

// func archFloor(x float64) float64

TEXT ·archFloor(SB),NOSPLIT,$0

MOVQ x+0(FP), AX

MOVQ $~(1<<63), DX // sign bit mask

ANDQ AX,DX // DX = |x|

SUBQ $1,DX

MOVQ $(Big - 1), CX // if |x| >= 2**52-1 or IsNaN(x) or |x| == 0, return x

CMPQ DX,CX

JAE isBig_floor

MOVQ AX, X0 // X0 = x

CVTTSD2SQ X0, AX

CVTSQ2SD AX, X1 // X1 = float(int(x))

CMPSD X1, X0, 1 // compare LT; X0 = 0xffffffffffffffff or 0

MOVSD $(-1.0), X2

ANDPD X2, X0 // if x < float(int(x)) {X0 = -1} else {X0 = 0}

ADDSD X1, X0

MOVSD X0, ret+8(FP)

RET

isBig_floor:

MOVQ AX, ret+8(FP) // return x

RET

// func archCeil(x float64) float64

TEXT ·archCeil(SB),NOSPLIT,$0

MOVQ x+0(FP), AX

MOVQ $~(1<<63), DX // sign bit mask

MOVQ AX, BX // BX = copy of x

ANDQ DX, BX // BX = |x|

MOVQ $Big, CX // if |x| >= 2**52 or IsNaN(x), return x

CMPQ BX, CX

JAE isBig_ceil

MOVQ AX, X0 // X0 = x

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

TEXT ·archTrunc(SB),NOSPLIT,$0

MOVQ x+0(FP), AX

MOVQ $~(1<<63), DX // sign bit mask

MOVQ AX, BX // BX = copy of x

ANDQ DX, BX // BX = |x|

MOVQ $Big, CX // if |x| >= 2**52 or IsNaN(x), return x

CMPQ BX, CX

JAE isBig_trunc

MOVQ AX, X0

MOVQ DX, X2 // X2 = sign bit mask

CVTTSD2SQ X0, AX

ANDNPD X0, X2 // X2 = sign

CVTSQ2SD AX, X0 // X0 = float(int(x))

ORPD X2, X0 // if X0 = 0.0, incorporate sign

MOVSD X0, ret+8(FP)

RET

isBig_trunc:

MOVQ AX, ret+8(FP) // return x

RET