1// Copyright ©2016 The Gonum Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style 3// license that can be found in the LICENSE file. 4// 5// Some of the loop unrolling code is copied from: 6// http://golang.org/src/math/big/arith_amd64.s 7// which is distributed under these terms: 8// 9// Copyright (c) 2012 The Go Authors. All rights reserved. 10// 11// Redistribution and use in source and binary forms, with or without 12// modification, are permitted provided that the following conditions are 13// met: 14// 15// * Redistributions of source code must retain the above copyright 16// notice, this list of conditions and the following disclaimer. 17// * Redistributions in binary form must reproduce the above 18// copyright notice, this list of conditions and the following disclaimer 19// in the documentation and/or other materials provided with the 20// distribution. 21// * Neither the name of Google Inc. nor the names of its 22// contributors may be used to endorse or promote products derived from 23// this software without specific prior written permission. 24// 25// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 26// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 27// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 28// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 29// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 30// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 31// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 32// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 33// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 35// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 36 37// +build !noasm,!gccgo,!safe 38 39#include "textflag.h" 40 41#define MOVDDUP_ALPHA LONG $0x44120FF2; WORD $0x2024 // @ MOVDDUP 32(SP), X0 /*XMM0, 32[RSP]*/ 42 43#define X_PTR SI 44#define DST_PTR DI 45#define IDX AX 46#define LEN CX 47#define TAIL BX 48#define ALPHA X0 49#define ALPHA_2 X1 50 51// func ScalUnitaryTo(dst []float64, alpha float64, x []float64) 52// This function assumes len(dst) >= len(x). 53TEXT ·ScalUnitaryTo(SB), NOSPLIT, $0 54 MOVQ x_base+32(FP), X_PTR // X_PTR = &x 55 MOVQ dst_base+0(FP), DST_PTR // DST_PTR = &dst 56 MOVDDUP_ALPHA // ALPHA = { alpha, alpha } 57 MOVQ x_len+40(FP), LEN // LEN = len(x) 58 CMPQ LEN, $0 59 JE end // if LEN == 0 { return } 60 61 XORQ IDX, IDX // IDX = 0 62 MOVQ LEN, TAIL 63 ANDQ $7, TAIL // TAIL = LEN % 8 64 SHRQ $3, LEN // LEN = floor( LEN / 8 ) 65 JZ tail_start // if LEN == 0 { goto tail_start } 66 67 MOVUPS ALPHA, ALPHA_2 // ALPHA_2 = ALPHA for pipelining 68 69loop: // do { // dst[i] = alpha * x[i] unrolled 8x. 70 MOVUPS (X_PTR)(IDX*8), X2 // X_i = x[i] 71 MOVUPS 16(X_PTR)(IDX*8), X3 72 MOVUPS 32(X_PTR)(IDX*8), X4 73 MOVUPS 48(X_PTR)(IDX*8), X5 74 75 MULPD ALPHA, X2 // X_i *= ALPHA 76 MULPD ALPHA_2, X3 77 MULPD ALPHA, X4 78 MULPD ALPHA_2, X5 79 80 MOVUPS X2, (DST_PTR)(IDX*8) // dst[i] = X_i 81 MOVUPS X3, 16(DST_PTR)(IDX*8) 82 MOVUPS X4, 32(DST_PTR)(IDX*8) 83 MOVUPS X5, 48(DST_PTR)(IDX*8) 84 85 ADDQ $8, IDX // i += 8 86 DECQ LEN 87 JNZ loop // while --LEN > 0 88 CMPQ TAIL, $0 89 JE end // if TAIL == 0 { return } 90 91tail_start: // Reset loop counters 92 MOVQ TAIL, LEN // Loop counter: LEN = TAIL 93 SHRQ $1, LEN // LEN = floor( TAIL / 2 ) 94 JZ tail_one // if LEN == 0 { goto tail_one } 95 96tail_two: // do { 97 MOVUPS (X_PTR)(IDX*8), X2 // X_i = x[i] 98 MULPD ALPHA, X2 // X_i *= ALPHA 99 MOVUPS X2, (DST_PTR)(IDX*8) // dst[i] = X_i 100 ADDQ $2, IDX // i += 2 101 DECQ LEN 102 JNZ tail_two // while --LEN > 0 103 104 ANDQ $1, TAIL 105 JZ end // if TAIL == 0 { return } 106 107tail_one: 108 MOVSD (X_PTR)(IDX*8), X2 // X_i = x[i] 109 MULSD ALPHA, X2 // X_i *= ALPHA 110 MOVSD X2, (DST_PTR)(IDX*8) // dst[i] = X_i 111 112end: 113 RET 114