Editando: floor_amd64.s
// 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
Cancelar
Kerym Chaeceran