--- /dev/null
+// Copyright ©2015 The Gonum Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+//
+// Some of the loop unrolling code is copied from:
+// http://golang.org/src/math/big/arith_amd64.s
+// which is distributed under these terms:
+//
+// Copyright (c) 2012 The Go Authors. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+//+build !noasm,!appengine
+
+#include "textflag.h"
+
+// func DdotUnitary(x, y []float64) (sum float64)
+// This function assumes len(y) >= len(x).
+TEXT ·DotUnitary(SB), NOSPLIT, $0
+ MOVQ x+0(FP), R8
+ MOVQ x_len+8(FP), DI // n = len(x)
+ MOVQ y+24(FP), R9
+
+ MOVSD $(0.0), X7 // sum = 0
+ MOVSD $(0.0), X8 // sum = 0
+
+ MOVQ $0, SI // i = 0
+ SUBQ $4, DI // n -= 4
+ JL tail_uni // if n < 0 goto tail_uni
+
+loop_uni:
+ // sum += x[i] * y[i] unrolled 4x.
+ MOVUPD 0(R8)(SI*8), X0
+ MOVUPD 0(R9)(SI*8), X1
+ MOVUPD 16(R8)(SI*8), X2
+ MOVUPD 16(R9)(SI*8), X3
+ MULPD X1, X0
+ MULPD X3, X2
+ ADDPD X0, X7
+ ADDPD X2, X8
+
+ ADDQ $4, SI // i += 4
+ SUBQ $4, DI // n -= 4
+ JGE loop_uni // if n >= 0 goto loop_uni
+
+tail_uni:
+ ADDQ $4, DI // n += 4
+ JLE end_uni // if n <= 0 goto end_uni
+
+onemore_uni:
+ // sum += x[i] * y[i] for the remaining 1-3 elements.
+ MOVSD 0(R8)(SI*8), X0
+ MOVSD 0(R9)(SI*8), X1
+ MULSD X1, X0
+ ADDSD X0, X7
+
+ ADDQ $1, SI // i++
+ SUBQ $1, DI // n--
+ JNZ onemore_uni // if n != 0 goto onemore_uni
+
+end_uni:
+ // Add the four sums together.
+ ADDPD X8, X7
+ MOVSD X7, X0
+ UNPCKHPD X7, X7
+ ADDSD X0, X7
+ MOVSD X7, sum+48(FP) // Return final sum.
+ RET
+
+// func DdotInc(x, y []float64, n, incX, incY, ix, iy uintptr) (sum float64)
+TEXT ·DotInc(SB), NOSPLIT, $0
+ MOVQ x+0(FP), R8
+ MOVQ y+24(FP), R9
+ MOVQ n+48(FP), CX
+ MOVQ incX+56(FP), R11
+ MOVQ incY+64(FP), R12
+ MOVQ ix+72(FP), R13
+ MOVQ iy+80(FP), R14
+
+ MOVSD $(0.0), X7 // sum = 0
+ LEAQ (R8)(R13*8), SI // p = &x[ix]
+ LEAQ (R9)(R14*8), DI // q = &y[ix]
+ SHLQ $3, R11 // incX *= sizeof(float64)
+ SHLQ $3, R12 // indY *= sizeof(float64)
+
+ SUBQ $2, CX // n -= 2
+ JL tail_inc // if n < 0 goto tail_inc
+
+loop_inc:
+ // sum += *p * *q unrolled 2x.
+ MOVHPD (SI), X0
+ MOVHPD (DI), X1
+ ADDQ R11, SI // p += incX
+ ADDQ R12, DI // q += incY
+ MOVLPD (SI), X0
+ MOVLPD (DI), X1
+ ADDQ R11, SI // p += incX
+ ADDQ R12, DI // q += incY
+
+ MULPD X1, X0
+ ADDPD X0, X7
+
+ SUBQ $2, CX // n -= 2
+ JGE loop_inc // if n >= 0 goto loop_inc
+
+tail_inc:
+ ADDQ $2, CX // n += 2
+ JLE end_inc // if n <= 0 goto end_inc
+
+ // sum += *p * *q for the last iteration if n is odd.
+ MOVSD (SI), X0
+ MULSD (DI), X0
+ ADDSD X0, X7
+
+end_inc:
+ // Add the two sums together.
+ MOVSD X7, X0
+ UNPCKHPD X7, X7
+ ADDSD X0, X7
+ MOVSD X7, sum+88(FP) // Return final sum.
+ RET
OSDN Git Service
