install assembly math.Sqrt on amd64

R=r
DELTA=33  (32 added, 0 deleted, 1 changed)
OCL=34983
CL=34986

src/pkg/math/Makefile

@@ -5,7 +5,14 @@
 include $(GOROOT)/src/Make.$(GOARCH)
 
 TARG=math
-GOFILES=\
+
+OFILES_amd64=\
+	sqrt_amd64.$O\
+
+OFILES=\
+	$(OFILES_$(GOARCH))
+
+ALLGOFILES=\
 	asin.go\
 	atan.go\
 	atan2.go\
@@ -25,4 +32,11 @@ GOFILES=\
 	tan.go\
 	tanh.go\
 
+NOGOFILES=\
+	$(subst _$(GOARCH).$O,.go,$(OFILES_$(GOARCH)))
+
+GOFILES=\
+	$(filter-out $(NOGOFILES),$(ALLGOFILES))\
+	$(subst .go,_decl.go,$(NOGOFILES))\
+
 include $(GOROOT)/src/Make.pkg

src/pkg/math/sqrt_amd64.s

@@ -0,0 +1,10 @@
+// Copyright 2009 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.
+
+// func Sqrt(x float64) float64
+TEXT math·Sqrt(SB),7,$0
+	MOVSD x+0(FP), X0
+	SQRTSD X0, X0
+	MOVSD X0, r+8(FP)
+	RET

src/pkg/math/sqrt_decl.go

@@ -0,0 +1,8 @@
+// Copyright 2009 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
+
+func Sqrt(x float64) float64
+