| Christopher Ferris | 7c83a1e | 2013-02-26 01:30:00 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2008 The Android Open Source Project |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * * Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * * Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in |
| 12 | * the documentation and/or other materials provided with the |
| 13 | * distribution. |
| 14 | * |
| 15 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 16 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 17 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| 18 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| 19 | * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 20 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| 21 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
| 22 | * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| 23 | * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| 24 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| 25 | * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 26 | * SUCH DAMAGE. |
| 27 | */ |
| 28 | |
| 29 | #include <machine/asm.h> |
| 30 | |
| 31 | /* |
| 32 | * Optimized memset() for ARM. |
| 33 | * |
| 34 | * memset() returns its first argument. |
| 35 | */ |
| 36 | |
| 37 | ENTRY(bzero) |
| 38 | mov r2, r1 |
| 39 | mov r1, #0 |
| 40 | END(bzero) |
| 41 | |
| 42 | ENTRY(memset) |
| 43 | /* compute the offset to align the destination |
| 44 | * offset = (4-(src&3))&3 = -src & 3 |
| 45 | */ |
| 46 | .save {r0, r4-r7, lr} |
| 47 | stmfd sp!, {r0, r4-r7, lr} |
| 48 | rsb r3, r0, #0 |
| 49 | ands r3, r3, #3 |
| 50 | cmp r3, r2 |
| 51 | movhi r3, r2 |
| 52 | |
| 53 | /* splat r1 */ |
| 54 | mov r1, r1, lsl #24 |
| 55 | orr r1, r1, r1, lsr #8 |
| 56 | orr r1, r1, r1, lsr #16 |
| 57 | |
| 58 | movs r12, r3, lsl #31 |
| 59 | strcsb r1, [r0], #1 /* can't use strh (alignment unknown) */ |
| 60 | strcsb r1, [r0], #1 |
| 61 | strmib r1, [r0], #1 |
| 62 | subs r2, r2, r3 |
| 63 | ldmlsfd sp!, {r0, r4-r7, lr} /* return */ |
| 64 | bxls lr |
| 65 | |
| 66 | /* align the destination to a cache-line */ |
| 67 | mov r12, r1 |
| 68 | mov lr, r1 |
| 69 | mov r4, r1 |
| 70 | mov r5, r1 |
| 71 | mov r6, r1 |
| 72 | mov r7, r1 |
| 73 | |
| 74 | rsb r3, r0, #0 |
| 75 | ands r3, r3, #0x1C |
| 76 | beq 3f |
| 77 | cmp r3, r2 |
| 78 | andhi r3, r2, #0x1C |
| 79 | sub r2, r2, r3 |
| 80 | |
| 81 | /* conditionally writes 0 to 7 words (length in r3) */ |
| 82 | movs r3, r3, lsl #28 |
| 83 | stmcsia r0!, {r1, lr} |
| 84 | stmcsia r0!, {r1, lr} |
| 85 | stmmiia r0!, {r1, lr} |
| 86 | movs r3, r3, lsl #2 |
| 87 | strcs r1, [r0], #4 |
| 88 | |
| 89 | 3: |
| 90 | subs r2, r2, #32 |
| 91 | mov r3, r1 |
| 92 | bmi 2f |
| 93 | 1: subs r2, r2, #32 |
| 94 | stmia r0!, {r1,r3,r4,r5,r6,r7,r12,lr} |
| 95 | bhs 1b |
| 96 | 2: add r2, r2, #32 |
| 97 | |
| 98 | /* conditionally stores 0 to 31 bytes */ |
| 99 | movs r2, r2, lsl #28 |
| 100 | stmcsia r0!, {r1,r3,r12,lr} |
| 101 | stmmiia r0!, {r1, lr} |
| 102 | movs r2, r2, lsl #2 |
| 103 | strcs r1, [r0], #4 |
| 104 | strmih r1, [r0], #2 |
| 105 | movs r2, r2, lsl #2 |
| 106 | strcsb r1, [r0] |
| 107 | ldmfd sp!, {r0, r4-r7, lr} |
| 108 | bx lr |
| 109 | END(memset) |