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| 1 // Copyright 2009 The Go Authors. All rights reserved. | 1 // Copyright 2009 The Go Authors. All rights reserved. |
| 2 // Use of this source code is governed by a BSD-style | 2 // Use of this source code is governed by a BSD-style |
| 3 // license that can be found in the LICENSE file. | 3 // license that can be found in the LICENSE file. |
| 4 | 4 |
| 5 #include "arm/asm.h" | 5 #include "arm/asm.h" |
| 6 | 6 |
| 7 // This version works on pre v6 architectures | 7 // This version works on pre v6 architectures |
| 8 | 8 |
| 9 // bool cas(int32 *val, int32 old, int32 new) | 9 // bool cas(int32 *val, int32 old, int32 new) |
| 10 // Atomically: | 10 // Atomically: |
| 11 // if(*val == old){ | 11 // if(*val == old){ |
| 12 // *val = new; | 12 // *val = new; |
| 13 // return 1; | 13 // return 1; |
| 14 // }else | 14 // }else |
| 15 // return 0; | 15 // return 0; |
| 16 | 16 |
| 17 TEXT runtime·cas(SB),7,$0 | 17 TEXT runtime·cas(SB),7,$0 |
| 18 MOVW 0(FP), R0 // *val | 18 MOVW 0(FP), R0 // *val |
| 19 MOVW 4(FP), R1 // old | 19 MOVW 4(FP), R1 // old |
| 20 MOVW 8(FP), R2 // new | 20 MOVW 8(FP), R2 // new |
| 21 MOVW $1, R3 | 21 MOVW $1, R3 |
| 22 MOVW $runtime·cas_mutex(SB), R4 | 22 MOVW $runtime·cas_mutex(SB), R4 |
| 23 l: | |
| 24 SWPW (R4), R3 // acquire mutex | 23 SWPW (R4), R3 // acquire mutex |
| 25 CMP $0, R3 | 24 CMP $0, R3 |
| 26 BNE fail0 | 25 BNE fail0 |
| 27 ········ | 26 ········ |
| 28 MOVW (R0), R5 | 27 MOVW (R0), R5 |
| 29 CMP R1, R5 | 28 CMP R1, R5 |
| 30 BNE fail1 | 29 BNE fail1 |
| 31 ········ | 30 ········ |
| 32 MOVW R2, (R0)········ | 31 MOVW R2, (R0)········ |
| 33 MOVW R3, (R4) // release mutex | 32 MOVW R3, (R4) // release mutex |
| 34 MOVW $1, R0 | 33 MOVW $1, R0 |
| 35 RET | 34 RET |
| 36 fail1:·· | 35 fail1:·· |
| 37 MOVW R3, (R4) // release mutex | 36 MOVW R3, (R4) // release mutex |
| 38 fail0: | 37 fail0: |
| 39 MOVW $0, R0 | 38 MOVW $0, R0 |
| 40 RET | 39 RET |
| 41 · | 40 |
| 41 // bool casp(void **p, void *old, void *new) |
| 42 // Atomically: |
| 43 //» if(*p == old){ |
| 44 //» » *p = new; |
| 45 //» » return 1; |
| 46 //» }else |
| 47 //» » return 0; |
| 48 |
| 49 TEXT runtime·casp(SB),7,$0 |
| 50 » MOVW» 0(FP), R0» // *p |
| 51 » MOVW» 4(FP), R1» // old |
| 52 » MOVW» 8(FP), R2» // new |
| 53 » MOVW» $1, R3 |
| 54 » MOVW» $runtime·cas_mutex(SB), R4 |
| 55 » SWPW» (R4), R3» // acquire mutex |
| 56 » CMP» » $0, R3 |
| 57 » BNE» » failp0 |
| 58 »······· |
| 59 » MOVW» (R0), R5 |
| 60 » CMP» » R1, R5 |
| 61 » BNE» » failp1 |
| 62 »······· |
| 63 » MOVW» R2, (R0)»······· |
| 64 » MOVW» R3, (R4)» // release mutex |
| 65 » MOVW» $1, R0 |
| 66 » RET |
| 67 failp1:» |
| 68 » MOVW» R3, (R4)» // release mutex |
| 69 failp0: |
| 70 » MOVW» $0, R0 |
| 71 » RET |
| 72 |
| 42 DATA runtime·cas_mutex(SB)/4, $0 | 73 DATA runtime·cas_mutex(SB)/4, $0 |
| 43 GLOBL runtime·cas_mutex(SB), $4 | 74 GLOBL runtime·cas_mutex(SB), $4 |
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