github.com/lzhfromustc/gofuzz@v0.0.0-20211116160056-151b3108bbd1/runtime/memclr_arm.s (about) 1 // Inferno's libkern/memset-arm.s 2 // https://bitbucket.org/inferno-os/inferno-os/src/master/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 // See memclrNoHeapPointers Go doc for important implementation constraints. 34 35 // func memclrNoHeapPointers(ptr unsafe.Pointer, n uintptr) 36 TEXT runtime·memclrNoHeapPointers(SB),NOSPLIT,$0-8 37 MOVW ptr+0(FP), TO 38 MOVW n+4(FP), N 39 MOVW $0, R0 40 41 ADD N, TO, TOE /* to end pointer */ 42 43 CMP $4, N /* need at least 4 bytes to copy */ 44 BLT _1tail 45 46 _4align: /* align on 4 */ 47 AND.S $3, TO, TMP 48 BEQ _4aligned 49 50 MOVBU.P R0, 1(TO) /* implicit write back */ 51 B _4align 52 53 _4aligned: 54 SUB $31, TOE, TMP /* do 32-byte chunks if possible */ 55 CMP TMP, TO 56 BHS _4tail 57 58 MOVW R0, R1 /* replicate */ 59 MOVW R0, R2 60 MOVW R0, R3 61 MOVW R0, R4 62 MOVW R0, R5 63 MOVW R0, R6 64 MOVW R0, R7 65 66 _f32loop: 67 CMP TMP, TO 68 BHS _4tail 69 70 MOVM.IA.W [R0-R7], (TO) 71 B _f32loop 72 73 _4tail: 74 SUB $3, TOE, TMP /* do remaining words if possible */ 75 _4loop: 76 CMP TMP, TO 77 BHS _1tail 78 79 MOVW.P R0, 4(TO) /* implicit write back */ 80 B _4loop 81 82 _1tail: 83 CMP TO, TOE 84 BEQ _return 85 86 MOVBU.P R0, 1(TO) /* implicit write back */ 87 B _1tail 88 89 _return: 90 RET