1// Inferno's libkern/memset-arm.s 2// https://bitbucket.org/inferno-os/inferno-os/src/default/libkern/memset-arm.s 3// 4// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved. 5// Revisions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com). All rights reserved. 6// Portions Copyright 2009 The Go Authors. All rights reserved. 7// 8// Permission is hereby granted, free of charge, to any person obtaining a copy 9// of this software and associated documentation files (the "Software"), to deal 10// in the Software without restriction, including without limitation the rights 11// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 12// copies of the Software, and to permit persons to whom the Software is 13// furnished to do so, subject to the following conditions: 14// 15// The above copyright notice and this permission notice shall be included in 16// all copies or substantial portions of the Software. 17// 18// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 19// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 20// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 21// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 22// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 23// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 24// THE SOFTWARE. 25 26#include "textflag.h" 27 28#define TO R8 29#define TOE R11 30#define N R12 31#define TMP R12 /* N and TMP don't overlap */ 32 33// func memclrNoHeapPointers(ptr unsafe.Pointer, n uintptr) 34TEXT runtime·memclrNoHeapPointers(SB),NOSPLIT,$0-8 35 MOVW ptr+0(FP), TO 36 MOVW n+4(FP), N 37 MOVW $0, R0 38 39 ADD N, TO, TOE /* to end pointer */ 40 41 CMP $4, N /* need at least 4 bytes to copy */ 42 BLT _1tail 43 44_4align: /* align on 4 */ 45 AND.S $3, TO, TMP 46 BEQ _4aligned 47 48 MOVBU.P R0, 1(TO) /* implicit write back */ 49 B _4align 50 51_4aligned: 52 SUB $31, TOE, TMP /* do 32-byte chunks if possible */ 53 CMP TMP, TO 54 BHS _4tail 55 56 MOVW R0, R1 /* replicate */ 57 MOVW R0, R2 58 MOVW R0, R3 59 MOVW R0, R4 60 MOVW R0, R5 61 MOVW R0, R6 62 MOVW R0, R7 63 64_f32loop: 65 CMP TMP, TO 66 BHS _4tail 67 68 MOVM.IA.W [R0-R7], (TO) 69 B _f32loop 70 71_4tail: 72 SUB $3, TOE, TMP /* do remaining words if possible */ 73_4loop: 74 CMP TMP, TO 75 BHS _1tail 76 77 MOVW.P R0, 4(TO) /* implicit write back */ 78 B _4loop 79 80_1tail: 81 CMP TO, TOE 82 BEQ _return 83 84 MOVBU.P R0, 1(TO) /* implicit write back */ 85 B _1tail 86 87_return: 88 RET 89