diff --git a/src/math/sincos.go b/src/math/sincos.go
index 6e663d0c58..3ae193a3b2 100644
--- a/src/math/sincos.go
+++ b/src/math/sincos.go
@@ -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,
diff --git a/src/math/sincos_386.go b/src/math/sincos_386.go
new file mode 100644
index 0000000000..38bb050572
--- /dev/null
+++ b/src/math/sincos_386.go
@@ -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)
diff --git a/src/math/sincos_amd64.s b/src/math/sincos_amd64.s
deleted file mode 100644
index b9ef88c96b..0000000000
--- a/src/math/sincos_amd64.s
+++ /dev/null
@@ -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
diff --git a/src/math/sincos_amd64p32.s b/src/math/sincos_amd64p32.s
deleted file mode 100644
index db86029876..0000000000
--- a/src/math/sincos_amd64p32.s
+++ /dev/null
@@ -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"
diff --git a/src/math/sincos_arm.s b/src/math/sincos_arm.s
deleted file mode 100644
index d8d833cd78..0000000000
--- a/src/math/sincos_arm.s
+++ /dev/null
@@ -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)
diff --git a/src/math/stubs_arm64.s b/src/math/stubs_arm64.s
index d8c9aa8c01..4985974b48 100644
--- a/src/math/stubs_arm64.s
+++ b/src/math/stubs_arm64.s
@@ -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)
 
diff --git a/src/math/stubs_mips64x.s b/src/math/stubs_mips64x.s
index 21df5cc9a6..4090529711 100644
--- a/src/math/stubs_mips64x.s
+++ b/src/math/stubs_mips64x.s
@@ -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)
 
diff --git a/src/math/stubs_mipsx.s b/src/math/stubs_mipsx.s
index b869768173..7346442553 100644
--- a/src/math/stubs_mipsx.s
+++ b/src/math/stubs_mipsx.s
@@ -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)
 
diff --git a/src/math/stubs_ppc64x.s b/src/math/stubs_ppc64x.s
index b622016720..73e8ad9df4 100644
--- a/src/math/stubs_ppc64x.s
+++ b/src/math/stubs_ppc64x.s
@@ -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)
 
diff --git a/src/math/stubs_s390x.s b/src/math/stubs_s390x.s
index 8da55c54ab..260272ce88 100644
--- a/src/math/stubs_s390x.s
+++ b/src/math/stubs_s390x.s
@@ -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)