/* $NetBSD: memset_arm.S,v 1.2 2013/01/14 19:15:13 matt Exp $ */ /*- * Copyright (c) 2012 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Matt Thomas of 3am Software Foundry. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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> #if defined(NEON) #define STORE8 vst1.32 {d0}, [ip:64]! #define STORE16 vst1.32 {d0-d1}, [ip:64]! #define STORE32 vst1.32 {d0-d3}, [ip:64]! #elif defined(VFP) #define STORE8 vstmia ip!, {d0} #define STORE16 vstmia ip!, {d0-d1} #define STORE32 vstmia ip!, {d0-d3} #elif defined(_ARM_ARCH_DWORD_OK) #define STORE8 strd r2, [ip], #8 #define STORE16 STORE8; STORE8 #define STORE32 STORE16; STORE16 #else #define STORE8 stmia ip!, {r2,r3} #define STORE16 STORE8; STORE8 #define STORE32 STORE16; STORE16 #endif /* * memset: Sets a block of memory to the specified value * Using NEON instructions * * On entry: * r0 - dest address * r1 - byte to write * r2 - number of bytes to write * * On exit: * r0 - dest address */ /* LINTSTUB: Func: void *memset(void *, int, size_t) */ ENTRY(memset) ands r3, r1, #0xff /* We deal with bytes */ orrne r3, r3, r3, lsl #8 /* replicate to all bytes */ orrne r3, r3, r3, lsl #16 /* replicate to all bytes */ movs r1, r2 /* we need r2 & r3 */ RETc(eq) /* return if length is 0 */ mov ip, r0 /* r0 needs to stay the same */ cmp r1, #12 /* is this a small memset? *? blt .Lbyte_by_byte /* then do it byte by byte */ /* Ok first we will dword align the address */ ands r2, ip, #7 /* grab the bottom three bits */ beq .Lmemset_dwordaligned /* The addr is dword aligned */ rsb r2, r2, #8 /* how far until dword aligned? */ sub r1, r1, r2 /* subtract it from remaining length */ mov r2, r3 /* duplicate fill value */ tst ip, #1 /* halfword aligned? */ strneb r3, [ip], #1 /* no, write a byte */ tst ip, #2 /* word aligned? */ strneh r3, [ip], #2 /* no, write a halfword */ tst ip, #4 /* dword aligned? */ strne r3, [ip], #4 /* no, write a word */ /* We are now doubleword aligned */ .Lmemset_dwordaligned: #if defined(NEON) vdup.8 q0, r3 /* move fill to SIMD */ vmov q1, q0 /* put fill in q1 (d2-d3) */ #elif defined(VFP) mov r2, r3 /* duplicate fill value */ vmov d0, r2, r3 /* move to VFP */ vmov d1, r2, r3 vmov d2, r2, r3 vmov d3, r2, r3 #endif #if 1 cmp r1, #128 blt .Lmemset_mainloop ands r2, ip, #63 /* check for 64-byte alignment */ beq .Lmemset_mainloop /* * Let's align to a 64-byte boundary so that stores don't cross * cacheline boundaries. We also know we have at least 128-bytes to * copy so we don't have to worry about the length at the moment. */ rsb r2, r2, #64 /* how many bytes until 64 bytes */ sub r1, r1, r2 /* subtract from remaining length */ #if !defined(NEON) && !defined(VFP) mov r2, r3 /* put fill back in r2 */ #endif tst ip, #8 /* quadword aligned? */ beq 1f /* yes */ STORE8 /* no, store a dword */ 1: tst ip, #16 /* octaword aligned? *? beq 2f /* yes */ STORE16 /* no, store a quadword */ 2: tst ip, #32 /* 32 word aligned? */ beq .Lmemset_mainloop /* yes */ STORE32 /* no, make 64-byte aligned */ #endif .Lmemset_mainloop: #if !defined(NEON) && !defined(VFP) mov r2, r3 /* put fill back in r2 */ #endif subs r1, r1, #64 /* subtract an initial 64 */ blt .Lmemset_lessthan_64bytes 3: STORE32 /* store first octaword */ STORE32 /* store second octaword */ RETc(eq) /* return if done */ subs r1, r1, #64 /* subtract another 64 */ bge 3b /* and do other if still >= 0 */ .Lmemset_lessthan_64bytes: tst r1, #32 /* do we have 16 bytes left? */ beq .Lmemset_lessthan_32bytes STORE32 /* yes, store an octaword */ bics r1, r1, #32 /* subtract 16 */ RETc(eq) /* return if length is 0 */ .Lmemset_lessthan_32bytes: tst r1, #16 /* do we have 16 bytes left? */ beq .Lmemset_lessthan_16bytes STORE16 /* yes, store a quadword */ bics r1, r1, #16 /* subtract 16 */ RETc(eq) /* return if length is 0 */ .Lmemset_lessthan_16bytes: tst r1, #8 /* do we have 8 bytes left? */ beq .Lmemset_lessthan_8bytes/* no */ STORE8 /* yes, store a dword */ bics r1, r1, #8 /* subtract 8 */ RETc(eq) /* return if length is 0 */ .Lmemset_lessthan_8bytes: tst r1, #4 /* do we have a word left? */ strne r2, [ip], #4 /* yes, so write one */ tst r1, #2 /* do we have a halfword left? */ strneh r2, [ip], #2 /* yes, so write one */ tst r1, #1 /* do we have a byte left? */ strneb r2, [ip], #1 /* yes, so write one */ RET /* return */ .Lbyte_by_byte: subs r1, r1, #1 /* can we write a byte? */ RETc(lt) /* no, we're done */ strb r3, [ip], #1 /* yes, so do it */ b .Lbyte_by_byte /* try next byte */ END(memset)
