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 <private/bionic_asm.h> 30 31 /* 32 * This code assumes it is running on a processor that supports all arm v7 33 * instructions, that supports neon instructions, and that supports 34 * unaligned neon instruction accesses to memory. 35 */ 36 37 .fpu neon 38 .syntax unified 39 40 ENTRY(__memset_chk) 41 cmp r2, r3 42 bls memset 43 44 // Preserve lr for backtrace. 45 push {lr} 46 .cfi_def_cfa_offset 4 47 .cfi_rel_offset lr, 0 48 49 bl __memset_chk_fail 50 END(__memset_chk) 51 52 /* memset() returns its first argument. */ 53 ENTRY(memset) 54 mov r3, r0 55 vdup.8 q0, r1 56 57 /* make sure we have at least 32 bytes to write */ 58 subs r2, r2, #32 59 blo 2f 60 vmov q1, q0 61 62 1: /* The main loop writes 32 bytes at a time */ 63 subs r2, r2, #32 64 vst1.8 {d0 - d3}, [r3]! 65 bhs 1b 66 67 2: /* less than 32 left */ 68 add r2, r2, #32 69 tst r2, #0x10 70 beq 3f 71 72 // writes 16 bytes, 128-bits aligned 73 vst1.8 {d0, d1}, [r3]! 74 3: /* write up to 15-bytes (count in r2) */ 75 movs ip, r2, lsl #29 76 bcc 1f 77 vst1.8 {d0}, [r3]! 78 1: bge 2f 79 vst1.32 {d0[0]}, [r3]! 80 2: movs ip, r2, lsl #31 81 strbmi r1, [r3], #1 82 strbcs r1, [r3], #1 83 strbcs r1, [r3], #1 84 bx lr 85 END(memset) 86
