cybercyst/go
1
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-05-28 10:51:22 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

math: remove asm version of sincos everywhere, except 386

Browse Source 
We have dedicated asm implementation of sincos only on 386 and amd64,
on everything else we are just jumping to generic version.
However amd64 version is actually slower than generic one:

Sincos-6               34.4ns ± 0%   24.8ns ± 0%  -27.79%  (p=0.000 n=8+10)

So remove all sincos*.s and keep only generic and 386.

Updates #19819

Change-Id: I7eefab35743729578264f52f6d23ee2c227c92a5
Reviewed-on: https://go-review.googlesource.com/41200
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This commit is contained in:
Ilya Tocar 2017-04-20 14:07:57 -05:00
parent 1737aef270
commit bc6459ac6c
10 changed files with 16 additions and 173 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
src/math/sincos.go
View File

@ -2,6 +2,8 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build !386
package math
// Coefficients _sin[] and _cos[] are found in pkg/math/sin.go.
@ -12,9 +14,7 @@ package math
// Sincos(±0) = ±0, 1
// Sincos(±Inf) = NaN, NaN
// Sincos(NaN) = NaN, NaN
func Sincos(x float64) (sin, cos float64)
func sincos(x float64) (sin, cos float64) {
func Sincos(x float64) (sin, cos float64) {
const (
PI4A = 7.85398125648498535156E-1 // 0x3fe921fb40000000, Pi/4 split into three parts
PI4B = 3.77489470793079817668E-8 // 0x3e64442d00000000,

13
src/math/sincos_386.go Normal file
View File

@ -0,0 +1,13 @@
// Copyright 2017 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.
package math
// Sincos returns Sin(x), Cos(x).
//
// Special cases are:
// Sincos(±0) = ±0, 1
// Sincos(±Inf) = NaN, NaN
// Sincos(NaN) = NaN, NaN
func Sincos(x float64) (sin, cos float64)

142
src/math/sincos_amd64.s
View File

@ -1,142 +0,0 @@
// Copyright 2010 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"
// The method is based on a paper by Naoki Shibata: "Efficient evaluation
// methods of elementary functions suitable for SIMD computation", Proc.
// of International Supercomputing Conference 2010 (ISC'10), pp. 25 -- 32
// (May 2010). The paper is available at
// http://www.springerlink.com/content/340228x165742104/
//
// The original code and the constants below are from the author's
// implementation available at http://freshmeat.net/projects/sleef.
// The README file says, "The software is in public domain.
// You can use the software without any obligation."
//
// This code is a simplified version of the original.
#define PosOne 0x3FF0000000000000
#define PosInf 0x7FF0000000000000
#define NaN 0x7FF8000000000001
#define PI4A 0.7853981554508209228515625 // pi/4 split into three parts
#define PI4B 0.794662735614792836713604629039764404296875e-8
#define PI4C 0.306161699786838294306516483068750264552437361480769e-16
#define M4PI 1.273239544735162542821171882678754627704620361328125 // 4/pi
#define T0 1.0
#define T1 -8.33333333333333333333333e-02 // (-1.0/12)
#define T2 2.77777777777777777777778e-03 // (+1.0/360)
#define T3 -4.96031746031746031746032e-05 // (-1.0/20160)
#define T4 5.51146384479717813051146e-07 // (+1.0/1814400)
// func Sincos(d float64) (sin, cos float64)
TEXT ·Sincos(SB),NOSPLIT,$0
// test for special cases
MOVQ $~(1<<63), DX // sign bit mask
MOVQ x+0(FP), BX
ANDQ BX, DX
JEQ isZero
MOVQ $PosInf, AX
CMPQ AX, DX
JLE isInfOrNaN
// Reduce argument
MOVQ BX, X7 // x7= d
MOVQ DX, X0 // x0= |d|
MOVSD $M4PI, X2
MULSD X0, X2
CVTTSD2SQ X2, BX // bx= q
MOVQ $1, AX
ANDQ BX, AX
ADDQ BX, AX
CVTSQ2SD AX, X2
MOVSD $PI4A, X3
MULSD X2, X3
SUBSD X3, X0
MOVSD $PI4B, X3
MULSD X2, X3
SUBSD X3, X0
MOVSD $PI4C, X3
MULSD X2, X3
SUBSD X3, X0
MULSD $0.125, X0 // x0= x, x7= d, bx= q
// Evaluate Taylor series
MULSD X0, X0
MOVSD $T4, X2
MULSD X0, X2
ADDSD $T3, X2
MULSD X0, X2
ADDSD $T2, X2
MULSD X0, X2
ADDSD $T1, X2
MULSD X0, X2
ADDSD $T0, X2
MULSD X2, X0 // x0= x, x7= d, bx= q
// Apply double angle formula
MOVSD $4.0, X2
SUBSD X0, X2
MULSD X2, X0
MOVSD $4.0, X2
SUBSD X0, X2
MULSD X2, X0
MOVSD $4.0, X2
SUBSD X0, X2
MULSD X2, X0
MULSD $0.5, X0 // x0= x, x7= d, bx= q
// sin = sqrt((2 - x) * x)
MOVSD $2.0, X2
SUBSD X0, X2
MULSD X0, X2
SQRTSD X2, X2 // x0= x, x2= z, x7= d, bx= q
// cos = 1 - x
MOVSD $1.0, X1
SUBSD X0, X1 // x1= x, x2= z, x7= d, bx= q
// if ((q + 1) & 2) != 0 { sin, cos = cos, sin }
MOVQ $1, DX
ADDQ BX, DX
ANDQ $2, DX
SHRQ $1, DX
SUBQ $1, DX
MOVQ DX, X3
// sin = (y & z) | (^y & x)
MOVAPD X2, X0
ANDPD X3, X0 // x0= sin
MOVAPD X3, X4
ANDNPD X1, X4
ORPD X4, X0 // x0= sin, x1= x, x2= z, x3= y, x7= d, bx= q
// cos = (y & x) | (^y & z)
ANDPD X3, X1 // x1= cos
ANDNPD X2, X3
ORPD X3, X1 // x0= sin, x1= cos, x7= d, bx= q
// if ((q & 4) != 0) != (d < 0) { sin = -sin }
MOVQ BX, AX
MOVQ $61, CX
SHLQ CX, AX
MOVQ AX, X3
XORPD X7, X3
MOVQ $(1<<63), AX
MOVQ AX, X2 // x2= -0.0
ANDPD X2, X3
ORPD X3, X0 // x0= sin, x1= cos, x2= -0.0, bx= q
// if ((q + 2) & 4) != 0 { cos = -cos }
MOVQ $2, AX
ADDQ AX, BX
MOVQ $61, CX
SHLQ CX, BX
MOVQ BX, X3
ANDPD X2, X3
ORPD X3, X1 // x0= sin, x1= cos
// return (sin, cos)
MOVSD X0, sin+8(FP)
MOVSD X1, cos+16(FP)
RET
isZero: // return (±0.0, 1.0)
MOVQ BX, sin+8(FP)
MOVQ $PosOne, AX
MOVQ AX, cos+16(FP)
RET
isInfOrNaN: // return (NaN, NaN)
MOVQ $NaN, AX
MOVQ AX, sin+8(FP)
MOVQ AX, cos+16(FP)
RET

5
src/math/sincos_amd64p32.s
View File

@ -1,5 +0,0 @@
// Copyright 2013 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 "sincos_amd64.s"

8
src/math/sincos_arm.s
View File

@ -1,8 +0,0 @@
// Copyright 2011 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"
TEXT ·Sincos(SB),NOSPLIT,$0
B ·sincos(SB)

3
src/math/stubs_arm64.s
View File

@ -57,9 +57,6 @@ TEXT ·Mod(SB),NOSPLIT,$0
TEXT ·Remainder(SB),NOSPLIT,$0
B ·remainder(SB)
TEXT ·Sincos(SB),NOSPLIT,$0
B ·sincos(SB)
TEXT ·Sin(SB),NOSPLIT,$0
B ·sin(SB)

3
src/math/stubs_mips64x.s
View File

@ -75,9 +75,6 @@ TEXT ·Mod(SB),NOSPLIT,$0
TEXT ·Remainder(SB),NOSPLIT,$0
JMP ·remainder(SB)
TEXT ·Sincos(SB),NOSPLIT,$0
JMP ·sincos(SB)
TEXT ·Sin(SB),NOSPLIT,$0
JMP ·sin(SB)

3
src/math/stubs_mipsx.s
View File

@ -75,9 +75,6 @@ TEXT ·Mod(SB),NOSPLIT,$0
TEXT ·Remainder(SB),NOSPLIT,$0
JMP ·remainder(SB)
TEXT ·Sincos(SB),NOSPLIT,$0
JMP ·sincos(SB)
TEXT ·Sin(SB),NOSPLIT,$0
JMP ·sin(SB)

3
src/math/stubs_ppc64x.s
View File

@ -66,9 +66,6 @@ TEXT ·Mod(SB),NOSPLIT,$0
TEXT ·Remainder(SB),NOSPLIT,$0
BR ·remainder(SB)
TEXT ·Sincos(SB),NOSPLIT,$0
BR ·sincos(SB)
TEXT ·Sin(SB),NOSPLIT,$0
BR ·sin(SB)

3
src/math/stubs_s390x.s
View File

@ -52,9 +52,6 @@ TEXT ·Mod(SB),NOSPLIT,$0
TEXT ·Remainder(SB),NOSPLIT,$0
BR ·remainder(SB)
TEXT ·Sincos(SB),NOSPLIT,$0
BR ·sincos(SB)
TEXT ·Tan(SB),NOSPLIT,$0
BR ·tan(SB)