math/big: enable pure Go (no assembly) build with build tag
To use a pure Go implementation of the low-level arithmetic
functions (when no platform-specific assembly implementations
are available), set the build tag math_big_pure_go.
This will make it easy to vendor the math/big package where no
assembly is available (for instance for use with gc which relies
on 1.4 functionality for now).
Change-Id: I91e17c0fdc568a20ec1512d7c64621241dc60c17
Reviewed-on: https://go-review.googlesource.com/7856
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/src/math/big/arith_386.s b/src/math/big/arith_386.s
index eb17bc1..7c8ab8f 100644
--- a/src/math/big/arith_386.s
+++ b/src/math/big/arith_386.s
@@ -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 !math_big_pure_go
+
#include "textflag.h"
// This file provides fast assembly versions for the elementary
diff --git a/src/math/big/arith_amd64.s b/src/math/big/arith_amd64.s
index bb06e69..d2d5187 100644
--- a/src/math/big/arith_amd64.s
+++ b/src/math/big/arith_amd64.s
@@ -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 !math_big_pure_go
+
#include "textflag.h"
// This file provides fast assembly versions for the elementary
diff --git a/src/math/big/arith_amd64p32.s b/src/math/big/arith_amd64p32.s
index 908dbbd..8610e90 100644
--- a/src/math/big/arith_amd64p32.s
+++ b/src/math/big/arith_amd64p32.s
@@ -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 !math_big_pure_go
+
#include "textflag.h"
TEXT ·mulWW(SB),NOSPLIT,$0
diff --git a/src/math/big/arith_arm.s b/src/math/big/arith_arm.s
index a4c51c2..69590ff 100644
--- a/src/math/big/arith_arm.s
+++ b/src/math/big/arith_arm.s
@@ -2,6 +2,8 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
+// +build !math_big_pure_go
+
#include "textflag.h"
// This file provides fast assembly versions for the elementary
diff --git a/src/math/big/arith_arm64.s b/src/math/big/arith_arm64.s
index 4447ec5..6e10e47 100644
--- a/src/math/big/arith_arm64.s
+++ b/src/math/big/arith_arm64.s
@@ -2,6 +2,8 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
+// +build !math_big_pure_go
+
#include "textflag.h"
// This file provides fast assembly versions for the elementary
diff --git a/src/math/big/arith_decl.go b/src/math/big/arith_decl.go
index 068cc8d..1707aa4 100644
--- a/src/math/big/arith_decl.go
+++ b/src/math/big/arith_decl.go
@@ -2,6 +2,8 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
+// +build !math_big_pure_go
+
package big
// implemented in arith_$GOARCH.s
diff --git a/src/math/big/arith_decl_pure.go b/src/math/big/arith_decl_pure.go
new file mode 100644
index 0000000..e760a38
--- /dev/null
+++ b/src/math/big/arith_decl_pure.go
@@ -0,0 +1,55 @@
+// Copyright 2015 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.
+
+// +build math_big_pure_go
+
+package big
+
+func mulWW(x, y Word) (z1, z0 Word) {
+ return mulWW_g(x, y)
+}
+
+func divWW(x1, x0, y Word) (q, r Word) {
+ return divWW_g(x1, x0, y)
+}
+
+func addVV(z, x, y []Word) (c Word) {
+ return addVV_g(z, x, y)
+}
+
+func subVV(z, x, y []Word) (c Word) {
+ return subVV_g(z, x, y)
+}
+
+func addVW(z, x []Word, y Word) (c Word) {
+ return addVW_g(z, x, y)
+}
+
+func subVW(z, x []Word, y Word) (c Word) {
+ return subVW_g(z, x, y)
+}
+
+func shlVU(z, x []Word, s uint) (c Word) {
+ return shlVU_g(z, x, s)
+}
+
+func shrVU(z, x []Word, s uint) (c Word) {
+ return shrVU_g(z, x, s)
+}
+
+func mulAddVWW(z, x []Word, y, r Word) (c Word) {
+ return mulAddVWW_g(z, x, y, r)
+}
+
+func addMulVVW(z, x []Word, y Word) (c Word) {
+ return addMulVVW_g(z, x, y)
+}
+
+func divWVW(z []Word, xn Word, x []Word, y Word) (r Word) {
+ return divWVW_g(z, xn, x, y)
+}
+
+func bitLen(x Word) (n int) {
+ return bitLen_g(x)
+}
diff --git a/src/math/big/arith_ppc64x.s b/src/math/big/arith_ppc64x.s
index 0cbd126..d4d4171 100644
--- a/src/math/big/arith_ppc64x.s
+++ b/src/math/big/arith_ppc64x.s
@@ -2,7 +2,7 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
-// +build ppc64 ppc64le
+// +build !math_big_pure_go,ppc64 !math_big_pure_go,ppc64le
#include "textflag.h"
