memset_arm.S revision 1.2.2.2
1 1.2.2.2 yamt /* $NetBSD: memset_arm.S,v 1.2.2.2 2013/01/23 00:04:06 yamt Exp $ */ 2 1.2.2.2 yamt 3 1.2.2.2 yamt /*- 4 1.2.2.2 yamt * Copyright (c) 2012 The NetBSD Foundation, Inc. 5 1.2.2.2 yamt * All rights reserved. 6 1.2.2.2 yamt * 7 1.2.2.2 yamt * This code is derived from software contributed to The NetBSD Foundation 8 1.2.2.2 yamt * by Matt Thomas of 3am Software Foundry. 9 1.2.2.2 yamt * 10 1.2.2.2 yamt * Redistribution and use in source and binary forms, with or without 11 1.2.2.2 yamt * modification, are permitted provided that the following conditions 12 1.2.2.2 yamt * are met: 13 1.2.2.2 yamt * 1. Redistributions of source code must retain the above copyright 14 1.2.2.2 yamt * notice, this list of conditions and the following disclaimer. 15 1.2.2.2 yamt * 2. Redistributions in binary form must reproduce the above copyright 16 1.2.2.2 yamt * notice, this list of conditions and the following disclaimer in the 17 1.2.2.2 yamt * documentation and/or other materials provided with the distribution. 18 1.2.2.2 yamt * 19 1.2.2.2 yamt * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 1.2.2.2 yamt * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 1.2.2.2 yamt * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 1.2.2.2 yamt * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 1.2.2.2 yamt * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 1.2.2.2 yamt * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 1.2.2.2 yamt * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 1.2.2.2 yamt * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 1.2.2.2 yamt * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 1.2.2.2 yamt * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 1.2.2.2 yamt * POSSIBILITY OF SUCH DAMAGE. 30 1.2.2.2 yamt */ 31 1.2.2.2 yamt #include <machine/asm.h> 32 1.2.2.2 yamt 33 1.2.2.2 yamt #if defined(NEON) 34 1.2.2.2 yamt #define STORE8 vst1.32 {d0}, [ip:64]! 35 1.2.2.2 yamt #define STORE16 vst1.32 {d0-d1}, [ip:64]! 36 1.2.2.2 yamt #define STORE32 vst1.32 {d0-d3}, [ip:64]! 37 1.2.2.2 yamt #elif defined(VFP) 38 1.2.2.2 yamt #define STORE8 vstmia ip!, {d0} 39 1.2.2.2 yamt #define STORE16 vstmia ip!, {d0-d1} 40 1.2.2.2 yamt #define STORE32 vstmia ip!, {d0-d3} 41 1.2.2.2 yamt #elif defined(_ARM_ARCH_DWORD_OK) 42 1.2.2.2 yamt #define STORE8 strd r2, [ip], #8 43 1.2.2.2 yamt #define STORE16 STORE8; STORE8 44 1.2.2.2 yamt #define STORE32 STORE16; STORE16 45 1.2.2.2 yamt #else 46 1.2.2.2 yamt #define STORE8 stmia ip!, {r2,r3} 47 1.2.2.2 yamt #define STORE16 STORE8; STORE8 48 1.2.2.2 yamt #define STORE32 STORE16; STORE16 49 1.2.2.2 yamt #endif 50 1.2.2.2 yamt /* 51 1.2.2.2 yamt * memset: Sets a block of memory to the specified value 52 1.2.2.2 yamt * Using NEON instructions 53 1.2.2.2 yamt * 54 1.2.2.2 yamt * On entry: 55 1.2.2.2 yamt * r0 - dest address 56 1.2.2.2 yamt * r1 - byte to write 57 1.2.2.2 yamt * r2 - number of bytes to write 58 1.2.2.2 yamt * 59 1.2.2.2 yamt * On exit: 60 1.2.2.2 yamt * r0 - dest address 61 1.2.2.2 yamt */ 62 1.2.2.2 yamt /* LINTSTUB: Func: void *memset(void *, int, size_t) */ 63 1.2.2.2 yamt ENTRY(memset) 64 1.2.2.2 yamt ands r3, r1, #0xff /* We deal with bytes */ 65 1.2.2.2 yamt orrne r3, r3, r3, lsl #8 /* replicate to all bytes */ 66 1.2.2.2 yamt orrne r3, r3, r3, lsl #16 /* replicate to all bytes */ 67 1.2.2.2 yamt movs r1, r2 /* we need r2 & r3 */ 68 1.2.2.2 yamt RETc(eq) /* return if length is 0 */ 69 1.2.2.2 yamt mov ip, r0 /* r0 needs to stay the same */ 70 1.2.2.2 yamt 71 1.2.2.2 yamt cmp r1, #12 /* is this a small memset? *? 72 1.2.2.2 yamt blt .Lbyte_by_byte /* then do it byte by byte */ 73 1.2.2.2 yamt 74 1.2.2.2 yamt /* Ok first we will dword align the address */ 75 1.2.2.2 yamt ands r2, ip, #7 /* grab the bottom three bits */ 76 1.2.2.2 yamt beq .Lmemset_dwordaligned /* The addr is dword aligned */ 77 1.2.2.2 yamt 78 1.2.2.2 yamt rsb r2, r2, #8 /* how far until dword aligned? */ 79 1.2.2.2 yamt sub r1, r1, r2 /* subtract it from remaining length */ 80 1.2.2.2 yamt mov r2, r3 /* duplicate fill value */ 81 1.2.2.2 yamt 82 1.2.2.2 yamt tst ip, #1 /* halfword aligned? */ 83 1.2.2.2 yamt strneb r3, [ip], #1 /* no, write a byte */ 84 1.2.2.2 yamt tst ip, #2 /* word aligned? */ 85 1.2.2.2 yamt strneh r3, [ip], #2 /* no, write a halfword */ 86 1.2.2.2 yamt tst ip, #4 /* dword aligned? */ 87 1.2.2.2 yamt strne r3, [ip], #4 /* no, write a word */ 88 1.2.2.2 yamt 89 1.2.2.2 yamt /* We are now doubleword aligned */ 90 1.2.2.2 yamt .Lmemset_dwordaligned: 91 1.2.2.2 yamt #if defined(NEON) 92 1.2.2.2 yamt vdup.8 q0, r3 /* move fill to SIMD */ 93 1.2.2.2 yamt vmov q1, q0 /* put fill in q1 (d2-d3) */ 94 1.2.2.2 yamt #elif defined(VFP) 95 1.2.2.2 yamt mov r2, r3 /* duplicate fill value */ 96 1.2.2.2 yamt vmov d0, r2, r3 /* move to VFP */ 97 1.2.2.2 yamt vmov d1, r2, r3 98 1.2.2.2 yamt vmov d2, r2, r3 99 1.2.2.2 yamt vmov d3, r2, r3 100 1.2.2.2 yamt #endif 101 1.2.2.2 yamt 102 1.2.2.2 yamt #if 1 103 1.2.2.2 yamt cmp r1, #128 104 1.2.2.2 yamt blt .Lmemset_mainloop 105 1.2.2.2 yamt ands r2, ip, #63 /* check for 64-byte alignment */ 106 1.2.2.2 yamt beq .Lmemset_mainloop 107 1.2.2.2 yamt /* 108 1.2.2.2 yamt * Let's align to a 64-byte boundary so that stores don't cross 109 1.2.2.2 yamt * cacheline boundaries. We also know we have at least 128-bytes to 110 1.2.2.2 yamt * copy so we don't have to worry about the length at the moment. 111 1.2.2.2 yamt */ 112 1.2.2.2 yamt rsb r2, r2, #64 /* how many bytes until 64 bytes */ 113 1.2.2.2 yamt sub r1, r1, r2 /* subtract from remaining length */ 114 1.2.2.2 yamt #if !defined(NEON) && !defined(VFP) 115 1.2.2.2 yamt mov r2, r3 /* put fill back in r2 */ 116 1.2.2.2 yamt #endif 117 1.2.2.2 yamt 118 1.2.2.2 yamt tst ip, #8 /* quadword aligned? */ 119 1.2.2.2 yamt beq 1f /* yes */ 120 1.2.2.2 yamt STORE8 /* no, store a dword */ 121 1.2.2.2 yamt 1: tst ip, #16 /* octaword aligned? *? 122 1.2.2.2 yamt beq 2f /* yes */ 123 1.2.2.2 yamt STORE16 /* no, store a quadword */ 124 1.2.2.2 yamt 2: tst ip, #32 /* 32 word aligned? */ 125 1.2.2.2 yamt beq .Lmemset_mainloop /* yes */ 126 1.2.2.2 yamt STORE32 /* no, make 64-byte aligned */ 127 1.2.2.2 yamt #endif 128 1.2.2.2 yamt 129 1.2.2.2 yamt .Lmemset_mainloop: 130 1.2.2.2 yamt #if !defined(NEON) && !defined(VFP) 131 1.2.2.2 yamt mov r2, r3 /* put fill back in r2 */ 132 1.2.2.2 yamt #endif 133 1.2.2.2 yamt subs r1, r1, #64 /* subtract an initial 64 */ 134 1.2.2.2 yamt blt .Lmemset_lessthan_64bytes 135 1.2.2.2 yamt 136 1.2.2.2 yamt 3: STORE32 /* store first octaword */ 137 1.2.2.2 yamt STORE32 /* store second octaword */ 138 1.2.2.2 yamt RETc(eq) /* return if done */ 139 1.2.2.2 yamt subs r1, r1, #64 /* subtract another 64 */ 140 1.2.2.2 yamt bge 3b /* and do other if still >= 0 */ 141 1.2.2.2 yamt .Lmemset_lessthan_64bytes: 142 1.2.2.2 yamt tst r1, #32 /* do we have 16 bytes left? */ 143 1.2.2.2 yamt beq .Lmemset_lessthan_32bytes 144 1.2.2.2 yamt STORE32 /* yes, store an octaword */ 145 1.2.2.2 yamt bics r1, r1, #32 /* subtract 16 */ 146 1.2.2.2 yamt RETc(eq) /* return if length is 0 */ 147 1.2.2.2 yamt .Lmemset_lessthan_32bytes: 148 1.2.2.2 yamt tst r1, #16 /* do we have 16 bytes left? */ 149 1.2.2.2 yamt beq .Lmemset_lessthan_16bytes 150 1.2.2.2 yamt STORE16 /* yes, store a quadword */ 151 1.2.2.2 yamt bics r1, r1, #16 /* subtract 16 */ 152 1.2.2.2 yamt RETc(eq) /* return if length is 0 */ 153 1.2.2.2 yamt .Lmemset_lessthan_16bytes: 154 1.2.2.2 yamt tst r1, #8 /* do we have 8 bytes left? */ 155 1.2.2.2 yamt beq .Lmemset_lessthan_8bytes/* no */ 156 1.2.2.2 yamt STORE8 /* yes, store a dword */ 157 1.2.2.2 yamt bics r1, r1, #8 /* subtract 8 */ 158 1.2.2.2 yamt RETc(eq) /* return if length is 0 */ 159 1.2.2.2 yamt .Lmemset_lessthan_8bytes: 160 1.2.2.2 yamt tst r1, #4 /* do we have a word left? */ 161 1.2.2.2 yamt strne r2, [ip], #4 /* yes, so write one */ 162 1.2.2.2 yamt tst r1, #2 /* do we have a halfword left? */ 163 1.2.2.2 yamt strneh r2, [ip], #2 /* yes, so write one */ 164 1.2.2.2 yamt tst r1, #1 /* do we have a byte left? */ 165 1.2.2.2 yamt strneb r2, [ip], #1 /* yes, so write one */ 166 1.2.2.2 yamt RET /* return */ 167 1.2.2.2 yamt 168 1.2.2.2 yamt .Lbyte_by_byte: 169 1.2.2.2 yamt subs r1, r1, #1 /* can we write a byte? */ 170 1.2.2.2 yamt RETc(lt) /* no, we're done */ 171 1.2.2.2 yamt strb r3, [ip], #1 /* yes, so do it */ 172 1.2.2.2 yamt b .Lbyte_by_byte /* try next byte */ 173 1.2.2.2 yamt END(memset) 174
Indexes created Wed Sep 24 14:09:57 GMT 2025