| // Inferno's libkern/memset-arm.s |
| // https://bitbucket.org/inferno-os/inferno-os/src/master/libkern/memset-arm.s |
| // |
| // Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved. |
| // Revisions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com). All rights reserved. |
| // Portions Copyright 2009 The Go Authors. All rights reserved. |
| // |
| // Permission is hereby granted, free of charge, to any person obtaining a copy |
| // of this software and associated documentation files (the "Software"), to deal |
| // in the Software without restriction, including without limitation the rights |
| // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| // copies of the Software, and to permit persons to whom the Software is |
| // furnished to do so, subject to the following conditions: |
| // |
| // The above copyright notice and this permission notice shall be included in |
| // all copies or substantial portions of the Software. |
| // |
| // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| // THE SOFTWARE. |
| |
| #include "textflag.h" |
| |
| #define TO R8 |
| #define TOE R11 |
| #define N R12 |
| #define TMP R12 /* N and TMP don't overlap */ |
| |
| // See memclrNoHeapPointers Go doc for important implementation constraints. |
| |
| // func memclrNoHeapPointers(ptr unsafe.Pointer, n uintptr) |
| // Also called from assembly in sys_windows_arm.s without g (but using Go stack convention). |
| TEXT runtime·memclrNoHeapPointers(SB),NOSPLIT,$0-8 |
| MOVW ptr+0(FP), TO |
| MOVW n+4(FP), N |
| MOVW $0, R0 |
| |
| ADD N, TO, TOE /* to end pointer */ |
| |
| CMP $4, N /* need at least 4 bytes to copy */ |
| BLT _1tail |
| |
| _4align: /* align on 4 */ |
| AND.S $3, TO, TMP |
| BEQ _4aligned |
| |
| MOVBU.P R0, 1(TO) /* implicit write back */ |
| B _4align |
| |
| _4aligned: |
| SUB $31, TOE, TMP /* do 32-byte chunks if possible */ |
| CMP TMP, TO |
| BHS _4tail |
| |
| MOVW R0, R1 /* replicate */ |
| MOVW R0, R2 |
| MOVW R0, R3 |
| MOVW R0, R4 |
| MOVW R0, R5 |
| MOVW R0, R6 |
| MOVW R0, R7 |
| |
| _f32loop: |
| CMP TMP, TO |
| BHS _4tail |
| |
| MOVM.IA.W [R0-R7], (TO) |
| B _f32loop |
| |
| _4tail: |
| SUB $3, TOE, TMP /* do remaining words if possible */ |
| _4loop: |
| CMP TMP, TO |
| BHS _1tail |
| |
| MOVW.P R0, 4(TO) /* implicit write back */ |
| B _4loop |
| |
| _1tail: |
| CMP TO, TOE |
| BEQ _return |
| |
| MOVBU.P R0, 1(TO) /* implicit write back */ |
| B _1tail |
| |
| _return: |
| RET |
