| // Copyright 2016 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,ppc64le |
| |
| #include "textflag.h" |
| |
| // This file provides fast assembly versions for the elementary |
| // arithmetic operations on vectors implemented in arith.go. |
| |
| // func divWW(x1, x0, y Word) (q, r Word) |
| TEXT ·divWW(SB), NOSPLIT, $0 |
| MOVD x1+0(FP), R4 |
| MOVD x0+8(FP), R5 |
| MOVD y+16(FP), R6 |
| |
| CMPU R4, R6 |
| BGE divbigger |
| |
| // from the programmer's note in ch. 3 of the ISA manual, p.74 |
| DIVDEU R6, R4, R3 |
| DIVDU R6, R5, R7 |
| MULLD R6, R3, R8 |
| MULLD R6, R7, R20 |
| SUB R20, R5, R10 |
| ADD R7, R3, R3 |
| SUB R8, R10, R4 |
| CMPU R4, R10 |
| BLT adjust |
| CMPU R4, R6 |
| BLT end |
| |
| adjust: |
| MOVD $1, R21 |
| ADD R21, R3, R3 |
| SUB R6, R4, R4 |
| |
| end: |
| MOVD R3, q+24(FP) |
| MOVD R4, r+32(FP) |
| |
| RET |
| |
| divbigger: |
| MOVD $-1, R7 |
| MOVD R7, q+24(FP) |
| MOVD R7, r+32(FP) |
| RET |
| |
