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 TEXT runtimememclrNoHeapPointers(SB),NOSPLIT,$0-8 34 MOVW ptr+0(FP), TO 35 MOVW n+4(FP), N 36 MOVW $0, R0 37 38 ADD N, TO, TOE /* to end pointer */ 39 40 CMP $4, N /* need at least 4 bytes to copy */ 41 BLT _1tail 42 43 _4align: /* align on 4 */ 44 AND.S $3, TO, TMP 45 BEQ _4aligned 46 47 MOVBU.P R0, 1(TO) /* implicit write back */ 48 B _4align 49 50 _4aligned: 51 SUB $31, TOE, TMP /* do 32-byte chunks if possible */ 52 CMP TMP, TO 53 BHS _4tail 54 55 MOVW R0, R1 /* replicate */ 56 MOVW R0, R2 57 MOVW R0, R3 58 MOVW R0, R4 59 MOVW R0, R5 60 MOVW R0, R6 61 MOVW R0, R7 62 63 _f32loop: 64 CMP TMP, TO 65 BHS _4tail 66 67 MOVM.IA.W [R0-R7], (TO) 68 B _f32loop 69 70 _4tail: 71 SUB $3, TOE, TMP /* do remaining words if possible */ 72 _4loop: 73 CMP TMP, TO 74 BHS _1tail 75 76 MOVW.P R0, 4(TO) /* implicit write back */ 77 B _4loop 78 79 _1tail: 80 CMP TO, TOE 81 BEQ _return 82 83 MOVBU.P R0, 1(TO) /* implicit write back */ 84 B _1tail 85 86 _return: 87 RET 88
