| /* |
| * Copyright (C) 2008 The Android Open Source Project |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
| * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| #include <machine/asm.h> |
| |
| /* |
| * Optimized memset() for ARM. |
| * |
| * memset() returns its first argument. |
| */ |
| |
| ENTRY(bzero) |
| mov r2, r1 |
| mov r1, #0 |
| END(bzero) |
| |
| ENTRY(memset) |
| /* compute the offset to align the destination |
| * offset = (4-(src&3))&3 = -src & 3 |
| */ |
| .save {r0, r4-r7, lr} |
| stmfd sp!, {r0, r4-r7, lr} |
| rsb r3, r0, #0 |
| ands r3, r3, #3 |
| cmp r3, r2 |
| movhi r3, r2 |
| |
| /* splat r1 */ |
| mov r1, r1, lsl #24 |
| orr r1, r1, r1, lsr #8 |
| orr r1, r1, r1, lsr #16 |
| |
| movs r12, r3, lsl #31 |
| strcsb r1, [r0], #1 /* can't use strh (alignment unknown) */ |
| strcsb r1, [r0], #1 |
| strmib r1, [r0], #1 |
| subs r2, r2, r3 |
| ldmlsfd sp!, {r0, r4-r7, lr} /* return */ |
| bxls lr |
| |
| /* align the destination to a cache-line */ |
| mov r12, r1 |
| mov lr, r1 |
| mov r4, r1 |
| mov r5, r1 |
| mov r6, r1 |
| mov r7, r1 |
| |
| rsb r3, r0, #0 |
| ands r3, r3, #0x1C |
| beq 3f |
| cmp r3, r2 |
| andhi r3, r2, #0x1C |
| sub r2, r2, r3 |
| |
| /* conditionnaly writes 0 to 7 words (length in r3) */ |
| movs r3, r3, lsl #28 |
| stmcsia r0!, {r1, lr} |
| stmcsia r0!, {r1, lr} |
| stmmiia r0!, {r1, lr} |
| movs r3, r3, lsl #2 |
| strcs r1, [r0], #4 |
| |
| 3: |
| subs r2, r2, #32 |
| mov r3, r1 |
| bmi 2f |
| 1: subs r2, r2, #32 |
| stmia r0!, {r1,r3,r4,r5,r6,r7,r12,lr} |
| bhs 1b |
| 2: add r2, r2, #32 |
| |
| /* conditionnaly stores 0 to 31 bytes */ |
| movs r2, r2, lsl #28 |
| stmcsia r0!, {r1,r3,r12,lr} |
| stmmiia r0!, {r1, lr} |
| movs r2, r2, lsl #2 |
| strcs r1, [r0], #4 |
| strmih r1, [r0], #2 |
| movs r2, r2, lsl #2 |
| strcsb r1, [r0] |
| ldmfd sp!, {r0, r4-r7, lr} |
| bx lr |
| END(memset) |