| Russ Cox | ed0beea | 2009-11-17 22:16:55 -0800 | [diff] [blame] | 1 | // Inferno's libkern/memmove-386.s |
| 2 | // http://code.google.com/p/inferno-os/source/browse/libkern/memmove-386.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 | |
| Rob Pike | 093493c | 2009-11-18 15:00:02 -0800 | [diff] [blame^] | 26 | TEXT memmove(SB), 7, $0 |
| Russ Cox | ed0beea | 2009-11-17 22:16:55 -0800 | [diff] [blame] | 27 | |
| 28 | MOVL to+0(FP), DI |
| 29 | MOVL fr+4(FP), SI |
| 30 | MOVL n+8(FP), BX |
| Rob Pike | 093493c | 2009-11-18 15:00:02 -0800 | [diff] [blame^] | 31 | CMPL BX, $0 |
| Russ Cox | ed0beea | 2009-11-17 22:16:55 -0800 | [diff] [blame] | 32 | JLT fault |
| 33 | |
| 34 | /* |
| 35 | * check and set for backwards |
| 36 | * should we look closer for overlap? |
| 37 | */ |
| 38 | CMPL SI, DI |
| 39 | JLS back |
| 40 | |
| 41 | /* |
| Rob Pike | 093493c | 2009-11-18 15:00:02 -0800 | [diff] [blame^] | 42 | * forward copy loop |
| Russ Cox | ed0beea | 2009-11-17 22:16:55 -0800 | [diff] [blame] | 43 | */ |
| 44 | MOVL BX, CX |
| 45 | SHRL $2, CX |
| 46 | ANDL $3, BX |
| 47 | |
| 48 | REP; MOVSL |
| 49 | MOVL BX, CX |
| 50 | REP; MOVSB |
| 51 | |
| 52 | MOVL to+0(FP),AX |
| 53 | RET |
| 54 | /* |
| 55 | * whole thing backwards has |
| 56 | * adjusted addresses |
| 57 | */ |
| 58 | back: |
| 59 | ADDL BX, DI |
| 60 | ADDL BX, SI |
| 61 | STD |
| 62 | |
| 63 | /* |
| 64 | * copy |
| 65 | */ |
| 66 | MOVL BX, CX |
| 67 | SHRL $2, CX |
| 68 | ANDL $3, BX |
| 69 | |
| 70 | SUBL $4, DI |
| 71 | SUBL $4, SI |
| 72 | REP; MOVSL |
| 73 | |
| 74 | ADDL $3, DI |
| 75 | ADDL $3, SI |
| 76 | MOVL BX, CX |
| 77 | REP; MOVSB |
| 78 | |
| 79 | CLD |
| 80 | MOVL to+0(FP),AX |
| 81 | RET |
| 82 | |
| 83 | /* |
| 84 | * if called with negative count, |
| 85 | * treat as error rather than |
| 86 | * rotating all of memory |
| 87 | */ |
| 88 | fault: |
| 89 | MOVL $0,SI |
| 90 | MOVL 0(SI), AX |
| 91 | RET |
