Module Name: src
Committed By: matt
Date: Sat Jan 12 20:27:13 UTC 2013
Added Files:
src/common/lib/libc/arch/arm/string: memset_arm.S
Log Message:
A version of memset that can do NEON, VFP as well as normal arm instructions
To generate a diff of this commit:
cvs rdiff -u -r0 -r1.1 src/common/lib/libc/arch/arm/string/memset_arm.S
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Added files:
Index: src/common/lib/libc/arch/arm/string/memset_arm.S
diff -u /dev/null src/common/lib/libc/arch/arm/string/memset_arm.S:1.1
--- /dev/null Sat Jan 12 20:27:13 2013
+++ src/common/lib/libc/arch/arm/string/memset_arm.S Sat Jan 12 20:27:13 2013
@@ -0,0 +1,173 @@
+/* $NetBSD: memset_arm.S,v 1.1 2013/01/12 20:27:13 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)
