1/* 2 * Copyright (c) 2015 ARM Ltd 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 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. The name of the company may not be used to endorse or promote 14 * products derived from this software without specific prior written 15 * permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY ARM LTD ``AS IS'' AND ANY EXPRESS OR IMPLIED 18 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL ARM LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 22 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 23 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 24 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 25 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 26 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 .arm 30 .syntax unified 31 .global memset 32 .type memset, %function 33memset: 34 tst r0, #3 35 stmfd sp!, {r4, lr} 36 beq 10f 37 cmp r2, #0 38 sub r2, r2, #1 39 beq 9f 40 and ip, r1, #255 41 mov r3, r0 42 b 2f 431: 44 cmp r2, #0 45 sub r2, r2, #1 46 beq 9f 472: 48 strb ip, [r3], #1 49 tst r3, #3 50 bne 1b 513: 52 cmp r2, #3 53 bls 7f 54 and lr, r1, #255 55 orr lr, lr, lr, asl #8 56 cmp r2, #15 57 orr lr, lr, lr, asl #16 58 bls 5f 59 mov r4, r2 60 add ip, r3, #16 614: 62 sub r4, r4, #16 63 cmp r4, #15 64 str lr, [ip, #-16] 65 str lr, [ip, #-12] 66 str lr, [ip, #-8] 67 str lr, [ip, #-4] 68 add ip, ip, #16 69 bhi 4b 70 sub ip, r2, #16 71 bic ip, ip, #15 72 and r2, r2, #15 73 add ip, ip, #16 74 cmp r2, #3 75 add r3, r3, ip 76 bls 7f 775: 78 mov r4, r3 79 mov ip, r2 806: 81 sub ip, ip, #4 82 cmp ip, #3 83 str lr, [r4], #4 84 bhi 6b 85 sub ip, r2, #4 86 bic ip, ip, #3 87 add ip, ip, #4 88 add r3, r3, ip 89 and r2, r2, #3 907: 91 cmp r2, #0 92 andne r1, r1, #255 93 addne r2, r3, r2 94 beq 9f 958: 96 strb r1, [r3], #1 97 cmp r3, r2 98 bne 8b 999: 100 ldmfd sp!, {r4, lr} 101 bx lr 10210: 103 mov r3, r0 104 b 3b 105 .size memset, . - memset 106