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Re: [PATCH] Optimize MIPS memcpy
On Tue, 2012-10-16 at 10:47 +1300, Maxim Kuvyrkov wrote:
> I suggest you move support for prepare-to-store prefetches into TODO category blocked on working
> IFUNC support for MIPS. Without IFUNCs and having all the different-sized cache lines on MIPS you
> can't make prepare-to-store work reliably.
>
> Once IFUNC support for MIPS is there, we can revisit using prepare-to-store prefetches.
>
> --
> Maxim Kuvyrkov
> CodeSourcery / Mentor Graphics
OK, Here is a version of memcpy that uses the STORE_STREAMING prefetch.
While it is optimized for a 32 byte prefetch, it will work correctly
regardless of the size of the prefetch.
Is this version OK to checkin?
Steve Ellcey
sellcey@mips.com
2012-10-17 Steve Ellcey <sellcey@mips.com>
* sysdeps/mips/memcpy.S: Add prefetching and more unrolling, make
it work in 32 or 64 bit modes.
* sysdeps/mips/mips64/memcpy.S: Remove.
diff --git a/ports/sysdeps/mips/memcpy.S b/ports/sysdeps/mips/memcpy.S
index 753f67c..71474e9 100644
--- a/ports/sysdeps/mips/memcpy.S
+++ b/ports/sysdeps/mips/memcpy.S
@@ -1,7 +1,8 @@
-/* Copyright (C) 2002-2012 Free Software Foundation, Inc.
+/* Copyright (C) 2012 Free Software Foundation, Inc.
This file is part of the GNU C Library.
- Contributed by Hartvig Ekner <hartvige@mips.com>, 2002.
-
+
+ Contributed by MIPS Technologies, Inc.
+
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
@@ -16,119 +17,616 @@
License along with the GNU C Library. If not, see
<http://www.gnu.org/licenses/>. */
+#ifdef ANDROID_CHANGES
+#include "machine/asm.h"
+#include "machine/regdef.h"
+#define USE_MEMMOVE_FOR_OVERLAP
+#define PREFETCH_LOAD_HINT PREFETCH_HINT_LOAD_STREAMED
+#define PREFETCH_STORE_HINT PREFETCH_HINT_PREPAREFORSTORE
+#elif _LIBC
#include <sysdep.h>
+#include <regdef.h>
+#include <sys/asm.h>
+#define PREFETCH_LOAD_HINT PREFETCH_HINT_LOAD_STREAMED
+#define PREFETCH_STORE_HINT PREFETCH_HINT_STORE_STREAMED
+#elif _COMPILING_NEWLIB
+#include "machine/asm.h"
+#include "machine/regdef.h"
+#define PREFETCH_LOAD_HINT PREFETCH_HINT_LOAD_STREAMED
+#define PREFETCH_STORE_HINT PREFETCH_HINT_STORE_STREAMED
+#else
+#include <regdef.h>
+#include <sys/asm.h>
+#endif
+
+#if (_MIPS_ISA == _MIPS_ISA_MIPS4) || (_MIPS_ISA == _MIPS_ISA_MIPS5) || \
+ (_MIPS_ISA == _MIPS_ISA_MIPS32) || (_MIPS_ISA == _MIPS_ISA_MIPS64)
+#ifndef DISABLE_PREFETCH
+#define USE_PREFETCH
+#endif
+#endif
+
+#if (_MIPS_SIM == _ABI64) || (_MIPS_SIM == _ABIN32)
+#ifndef DISABLE_DOUBLE
+#define USE_DOUBLE
+#endif
+#endif
+
+
+
+/* Some asm.h files do not have the L macro definition. */
+#ifndef L
+#if _MIPS_SIM == _ABIO32
+# define L(label) $L ## label
+#else
+# define L(label) .L ## label
+#endif
+#endif
+
+/* Some asm.h files do not have the PTR_ADDIU macro definition. */
+#ifndef PTR_ADDIU
+#ifdef USE_DOUBLE
+#define PTR_ADDIU daddiu
+#else
+#define PTR_ADDIU addiu
+#endif
+#endif
+
+/* Some asm.h files do not have the PTR_SRA macro definition. */
+#ifndef PTR_SRA
+#ifdef USE_DOUBLE
+#define PTR_SRA dsra
+#else
+#define PTR_SRA sra
+#endif
+#endif
+
+/*
+ * Using PREFETCH_HINT_LOAD_STREAMED instead of PREFETCH_LOAD on load
+ * prefetches appears to offer a slight preformance advantage.
+ *
+ * Using PREFETCH_HINT_PREPAREFORSTORE instead of PREFETCH_STORE
+ * or PREFETCH_STORE_STREAMED offers a large performance advantage
+ * but PREPAREFORSTORE has some special restrictions to consider.
+ *
+ * Prefetch with the 'prepare for store' hint does not copy a memory
+ * location into the cache, it just allocates a cache line and zeros
+ * it out. This means that if you do not write to the entire cache
+ * line before writing it out to memory some data will get zero'ed out
+ * when the cache line is written back to memory and data will be lost.
+ *
+ * Also if you are using this memcpy to copy overlapping buffers it may
+ * not behave correctly when using the 'prepare for store' hint. If you
+ * use the 'prepare for store' prefetch on a memory area that is in the
+ * memcpy source (as well as the memcpy destination), then you will get
+ * some data zero'ed out before you have a chance to read it and data will
+ * be lost.
+ *
+ * If you are going to use this memcpy routine with the 'prepare for store'
+ * prefetch you may want to set USE_MEMMOVE_FOR_OVERLAP in order to avoid
+ * the problem of running memcpy on overlapping buffers.
+ *
+ * There are ifdef'ed sections of this memcpy to make sure that it does not
+ * do prefetches on cache lines that are not going to be completely written.
+ * This code is only needed and only used when PREFETCH_STORE_HINT is set to
+ * PREFETCH_HINT_PREPAREFORSTORE. This code assumes that cache lines are
+ * 32 bytes and if the cache line is larger it will not work correctly.
+ */
-/* void *memcpy(void *s1, const void *s2, size_t n); */
+#ifdef USE_PREFETCH
+# define PREFETCH_HINT_LOAD 0
+# define PREFETCH_HINT_STORE 1
+# define PREFETCH_HINT_LOAD_STREAMED 4
+# define PREFETCH_HINT_STORE_STREAMED 5
+# define PREFETCH_HINT_LOAD_RETAINED 6
+# define PREFETCH_HINT_STORE_RETAINED 7
+# define PREFETCH_HINT_WRITEBACK_INVAL 25
+# define PREFETCH_HINT_PREPAREFORSTORE 30
+
+/*
+ * If we have not picked out what hints to use at this point use the
+ * standard load and store prefetch hints.
+ */
+#ifndef PREFETCH_STORE_HINT
+# define PREFETCH_STORE_HINT PREFETCH_HINT_STORE
+#endif
+#ifndef PREFETCH_LOAD_HINT
+# define PREFETCH_LOAD_HINT PREFETCH_HINT_LOAD
+#endif
+/*
+ * We double everything when USE_DOUBLE is true so we do 2 prefetches to
+ * get 64 bytes in that case. The assumption is that each individual
+ * prefetch brings in 32 bytes.
+ */
+#ifdef USE_DOUBLE
+# define PREFETCH_CHUNK 64
+# define PREFETCH_FOR_LOAD(chunk, reg) \
+ pref PREFETCH_LOAD_HINT, (chunk)*32(reg); \
+ pref PREFETCH_LOAD_HINT, ((chunk)+1)*32(reg)
+# define PREFETCH_FOR_STORE(chunk, reg) \
+ pref PREFETCH_STORE_HINT, (chunk)*32(reg); \
+ pref PREFETCH_STORE_HINT, ((chunk)+1)*32(reg)
+#else
+# define PREFETCH_CHUNK 32
+# define PREFETCH_FOR_LOAD(chunk, reg) \
+ pref PREFETCH_LOAD_HINT, (chunk)*32(reg)
+# define PREFETCH_FOR_STORE(chunk, reg) \
+ pref PREFETCH_STORE_HINT, (chunk)*32(reg)
+#endif
+# define PREFETCH_LIMIT (5 * PREFETCH_CHUNK)
+#else /* USE_PREFETCH not defined */
+# define PREFETCH_FOR_LOAD(offset, reg)
+# define PREFETCH_FOR_STORE(offset, reg)
+#endif
+
+/* Allow the routine to be named something else if desired. */
+#ifndef MEMCPY_NAME
+#define MEMCPY_NAME memcpy
+#endif
+
+/* We use these 32/64 bit registers as temporaries to do the copying. */
+#define REG0 t0
+#define REG1 t1
+#define REG2 t2
+#define REG3 t3
+#if _MIPS_SIM == _ABIO32
+# define REG4 t4
+# define REG5 t5
+# define REG6 t6
+# define REG7 t7
+#else
+# define REG4 ta0
+# define REG5 ta1
+# define REG6 ta2
+# define REG7 ta3
+#endif
+
+/* We load/store 64 bits at a time when USE_DOUBLE is true.
+ * The C_ prefix stands for CHUNK and is used to avoid macro name
+ * conflicts with system header files. */
+
+#ifdef USE_DOUBLE
+# define C_ST sd
+# define C_LD ld
#if __MIPSEB
-# define LWHI lwl /* high part is left in big-endian */
-# define SWHI swl /* high part is left in big-endian */
-# define LWLO lwr /* low part is right in big-endian */
-# define SWLO swr /* low part is right in big-endian */
+# define C_LDHI ldl /* high part is left in big-endian */
+# define C_STHI sdl /* high part is left in big-endian */
+# define C_LDLO ldr /* low part is right in big-endian */
+# define C_STLO sdr /* low part is right in big-endian */
+#else
+# define C_LDHI ldr /* high part is right in little-endian */
+# define C_STHI sdr /* high part is right in little-endian */
+# define C_LDLO ldl /* low part is left in little-endian */
+# define C_STLO sdl /* low part is left in little-endian */
+#endif
+#else
+# define C_ST sw
+# define C_LD lw
+#if __MIPSEB
+# define C_LDHI lwl /* high part is left in big-endian */
+# define C_STHI swl /* high part is left in big-endian */
+# define C_LDLO lwr /* low part is right in big-endian */
+# define C_STLO swr /* low part is right in big-endian */
+#else
+# define C_LDHI lwr /* high part is right in little-endian */
+# define C_STHI swr /* high part is right in little-endian */
+# define C_LDLO lwl /* low part is left in little-endian */
+# define C_STLO swl /* low part is left in little-endian */
+#endif
+#endif
+
+/* Bookkeeping values for 32 vs. 64 bit mode. */
+#ifdef USE_DOUBLE
+# define NSIZE 8
+# define NSIZEMASK 0x3f
+# define NSIZEDMASK 0x7f
#else
-# define LWHI lwr /* high part is right in little-endian */
-# define SWHI swr /* high part is right in little-endian */
-# define LWLO lwl /* low part is left in little-endian */
-# define SWLO swl /* low part is left in little-endian */
+# define NSIZE 4
+# define NSIZEMASK 0x1f
+# define NSIZEDMASK 0x3f
#endif
+#define UNIT(unit) ((unit)*NSIZE)
+#define UNITM1(unit) (((unit)*NSIZE)-1)
-ENTRY (memcpy)
+#ifdef ANDROID_CHANGES
+LEAF(MEMCPY_NAME, 0)
+#else
+LEAF(MEMCPY_NAME)
+#endif
+ .set nomips16
.set noreorder
+/*
+ * Below we handle the case where memcpy is called with overlapping src and dst.
+ * Although memcpy is not required to handle this case, some parts of Android
+ * like Skia rely on such usage. We call memmove to handle such cases.
+ */
+#ifdef USE_MEMMOVE_FOR_OVERLAP
+ PTR_SUBU t0,a0,a1
+ PTR_SRA t2,t0,31
+ xor t1,t0,t2
+ PTR_SUBU t0,t1,t2
+ sltu t2,t0,a2
+ beq t2,zero,L(memcpy)
+ la t9,memmove
+ jr t9
+ nop
+L(memcpy):
+#endif
+/*
+ * If the size is less then 2*NSIZE (8 or 16), go to L(lastb). Regardless of
+ * size, copy dst pointer to v0 for the return value.
+ */
+ slti t2,a2,(2 * NSIZE)
+ bne t2,zero,L(lastb)
+ move v0,a0
+/*
+ * If src and dst have different alignments, go to L(unaligned), if they
+ * have the same alignment (but are not actually aligned) do a partial
+ * load/store to make them aligned. If they are both already aligned
+ * we can start copying at L(aligned).
+ */
+ xor t8,a1,a0
+ andi t8,t8,(NSIZE-1) /* t8 is a0/a1 word-displacement */
+ bne t8,zero,L(unaligned)
+ PTR_SUBU a3, zero, a0
+
+ andi a3,a3,(NSIZE-1) /* copy a3 bytes to align a0/a1 */
+ beq a3,zero,L(aligned) /* if a3=0, it is already aligned */
+ PTR_SUBU a2,a2,a3 /* a2 is the remining bytes count */
+
+ C_LDHI t8,0(a1)
+ PTR_ADDU a1,a1,a3
+ C_STHI t8,0(a0)
+ PTR_ADDU a0,a0,a3
+
+/*
+ * Now dst/src are both aligned to (word or double word) aligned addresses
+ * Set a2 to count how many bytes we have to copy after all the 64/128 byte
+ * chunks are copied and a3 to the dst pointer after all the 64/128 byte
+ * chunks have been copied. We will loop, incrementing a0 and a1 until a0
+ * equals a3.
+ */
+
+L(aligned):
+ andi t8,a2,NSIZEDMASK /* any whole 64-byte/128-byte chunks? */
+ beq a2,t8,L(chkw) /* if a2==t8, no 64-byte/128-byte chunks */
+ PTR_SUBU a3,a2,t8 /* subtract from a2 the reminder */
+ PTR_ADDU a3,a0,a3 /* Now a3 is the final dst after loop */
+
+/* When in the loop we may prefetch with the 'prepare to store' hint,
+ * in this case the a0+x should not be past the "t0-32" address. This
+ * means: for x=128 the last "safe" a0 address is "t0-160". Alternatively,
+ * for x=64 the last "safe" a0 address is "t0-96" In the current version we
+ * will use "prefetch hint,128(a0)", so "t0-160" is the limit.
+ */
+#if (PREFETCH_STORE_HINT == PREFETCH_HINT_PREPAREFORSTORE)
+ PTR_ADDU t0,a0,a2 /* t0 is the "past the end" address */
+ PTR_SUBU t9,t0,PREFETCH_LIMIT /* t9 is the "last safe pref" address */
+#endif
+ PREFETCH_FOR_LOAD (0, a1)
+ PREFETCH_FOR_LOAD (1, a1)
+ PREFETCH_FOR_LOAD (2, a1)
+ PREFETCH_FOR_STORE (1, a0)
+#if (PREFETCH_STORE_HINT == PREFETCH_HINT_PREPAREFORSTORE)
+ sltu v1,t9,a0 /* If a0 > t9 don't use next prefetch */
+ bgtz v1,L(loop16w)
+ nop
+#endif
+ PREFETCH_FOR_STORE (2, a0)
+L(loop16w):
+ PREFETCH_FOR_LOAD (3, a1)
+ C_LD t0,UNIT(0)(a1)
+#if (PREFETCH_STORE_HINT == PREFETCH_HINT_PREPAREFORSTORE)
+ bgtz v1,L(skip_pref30_96)
+#endif
+ C_LD t1,UNIT(1)(a1)
+ PREFETCH_FOR_STORE (3, a0)
+L(skip_pref30_96):
+ C_LD REG2,UNIT(2)(a1)
+ C_LD REG3,UNIT(3)(a1)
+ C_LD REG4,UNIT(4)(a1)
+ C_LD REG5,UNIT(5)(a1)
+ C_LD REG6,UNIT(6)(a1)
+ C_LD REG7,UNIT(7)(a1)
+ PREFETCH_FOR_LOAD (4, a1)
+
+ C_ST t0,UNIT(0)(a0)
+ C_ST t1,UNIT(1)(a0)
+ C_ST REG2,UNIT(2)(a0)
+ C_ST REG3,UNIT(3)(a0)
+ C_ST REG4,UNIT(4)(a0)
+ C_ST REG5,UNIT(5)(a0)
+ C_ST REG6,UNIT(6)(a0)
+ C_ST REG7,UNIT(7)(a0)
+
+ C_LD t0,UNIT(8)(a1)
+#if (PREFETCH_STORE_HINT == PREFETCH_HINT_PREPAREFORSTORE)
+ bgtz v1,L(skip_pref30_128)
+#endif
+ C_LD t1,UNIT(9)(a1)
+ PREFETCH_FOR_STORE (4, a0)
+L(skip_pref30_128):
+ C_LD REG2,UNIT(10)(a1)
+ C_LD REG3,UNIT(11)(a1)
+ C_LD REG4,UNIT(12)(a1)
+ C_LD REG5,UNIT(13)(a1)
+ C_LD REG6,UNIT(14)(a1)
+ C_LD REG7,UNIT(15)(a1)
+ PREFETCH_FOR_LOAD (5, a1)
+ C_ST t0,UNIT(8)(a0)
+ C_ST t1,UNIT(9)(a0)
+ C_ST REG2,UNIT(10)(a0)
+ C_ST REG3,UNIT(11)(a0)
+ C_ST REG4,UNIT(12)(a0)
+ C_ST REG5,UNIT(13)(a0)
+ C_ST REG6,UNIT(14)(a0)
+ C_ST REG7,UNIT(15)(a0)
+ PTR_ADDIU a0,a0,UNIT(16) /* adding 64/128 to dest */
+#if (PREFETCH_STORE_HINT == PREFETCH_HINT_PREPAREFORSTORE)
+ sltu v1,t9,a0
+#endif
+ bne a0,a3,L(loop16w)
+ PTR_ADDIU a1,a1,UNIT(16) /* adding 64/128 to src */
+ move a2,t8
+
+/* Here we have src and dest word-aligned but less than 64-bytes or
+ * 128 bytes to go. Check for a 32(64) byte chunk and copy if if there
+ * is one. Otherwise jump down to L(chk1w) to handle the tail end of
+ * the copy.
+ */
+
+L(chkw):
+ PREFETCH_FOR_LOAD (0, a1)
+ andi t8,a2,NSIZEMASK /* Is there a 32-byte/64-byte chunk. */
+ /* The t8 is the reminder count past 32-bytes */
+ beq a2,t8,L(chk1w) /* When a2=t8, no 32-byte chunk */
+ nop
+ C_LD t0,UNIT(0)(a1)
+ C_LD t1,UNIT(1)(a1)
+ C_LD REG2,UNIT(2)(a1)
+ C_LD REG3,UNIT(3)(a1)
+ C_LD REG4,UNIT(4)(a1)
+ C_LD REG5,UNIT(5)(a1)
+ C_LD REG6,UNIT(6)(a1)
+ C_LD REG7,UNIT(7)(a1)
+ PTR_ADDIU a1,a1,UNIT(8)
+ C_ST t0,UNIT(0)(a0)
+ C_ST t1,UNIT(1)(a0)
+ C_ST REG2,UNIT(2)(a0)
+ C_ST REG3,UNIT(3)(a0)
+ C_ST REG4,UNIT(4)(a0)
+ C_ST REG5,UNIT(5)(a0)
+ C_ST REG6,UNIT(6)(a0)
+ C_ST REG7,UNIT(7)(a0)
+ PTR_ADDIU a0,a0,UNIT(8)
+
+/*
+ * Here we have less then 32(64) bytes to copy. Set up for a loop to
+ * copy one word (or double word) at a time. Set a2 to count how many
+ * bytes we have to copy after all the word (or double word) chunks are
+ * copied and a3 to the dst pointer after all the (d)word chunks have
+ * been copied. We will loop, incrementing a0 and a1 until a0 equals a3.
+ */
+L(chk1w):
+ andi a2,t8,(NSIZE-1) /* a2 is the reminder past one (d)word chunks */
+ beq a2,t8,L(lastb)
+ PTR_SUBU a3,t8,a2 /* a3 is count of bytes in one (d)word chunks */
+ PTR_ADDU a3,a0,a3 /* a3 is the dst address after loop */
+
+/* copying in words (4-byte or 8-byte chunks) */
+L(wordCopy_loop):
+ C_LD REG3,UNIT(0)(a1)
+ PTR_ADDIU a1,a1,UNIT(1)
+ PTR_ADDIU a0,a0,UNIT(1)
+ bne a0,a3,L(wordCopy_loop)
+ C_ST REG3,UNIT(-1)(a0)
- slti t0, a2, 8 # Less than 8?
- bne t0, zero, L(last8)
- move v0, a0 # Setup exit value before too late
-
- xor t0, a1, a0 # Find a0/a1 displacement
- andi t0, 0x3
- bne t0, zero, L(shift) # Go handle the unaligned case
- subu t1, zero, a1
- andi t1, 0x3 # a0/a1 are aligned, but are we
- beq t1, zero, L(chk8w) # starting in the middle of a word?
- subu a2, t1
- LWHI t0, 0(a1) # Yes we are... take care of that
- addu a1, t1
- SWHI t0, 0(a0)
- addu a0, t1
-
-L(chk8w):
- andi t0, a2, 0x1f # 32 or more bytes left?
- beq t0, a2, L(chk1w)
- subu a3, a2, t0 # Yes
- addu a3, a1 # a3 = end address of loop
- move a2, t0 # a2 = what will be left after loop
-L(lop8w):
- lw t0, 0(a1) # Loop taking 8 words at a time
- lw t1, 4(a1)
- lw t2, 8(a1)
- lw t3, 12(a1)
- lw t4, 16(a1)
- lw t5, 20(a1)
- lw t6, 24(a1)
- lw t7, 28(a1)
- addiu a0, 32
- addiu a1, 32
- sw t0, -32(a0)
- sw t1, -28(a0)
- sw t2, -24(a0)
- sw t3, -20(a0)
- sw t4, -16(a0)
- sw t5, -12(a0)
- sw t6, -8(a0)
- bne a1, a3, L(lop8w)
- sw t7, -4(a0)
-
-L(chk1w):
- andi t0, a2, 0x3 # 4 or more bytes left?
- beq t0, a2, L(last8)
- subu a3, a2, t0 # Yes, handle them one word at a time
- addu a3, a1 # a3 again end address
- move a2, t0
-L(lop1w):
- lw t0, 0(a1)
- addiu a0, 4
- addiu a1, 4
- bne a1, a3, L(lop1w)
- sw t0, -4(a0)
-
-L(last8):
- blez a2, L(lst8e) # Handle last 8 bytes, one at a time
- addu a3, a2, a1
-L(lst8l):
- lb t0, 0(a1)
- addiu a0, 1
- addiu a1, 1
- bne a1, a3, L(lst8l)
- sb t0, -1(a0)
-L(lst8e):
- jr ra # Bye, bye
+/* Copy the last 8 (or 16) bytes */
+L(lastb):
+ blez a2,L(leave)
+ PTR_ADDU a3,a0,a2 /* a3 is the last dst address */
+L(lastbloop):
+ lb v1,0(a1)
+ PTR_ADDIU a1,a1,1
+ PTR_ADDIU a0,a0,1
+ bne a0,a3,L(lastbloop)
+ sb v1,-1(a0)
+L(leave):
+ j ra
nop
+/*
+ * UNALIGNED case, got here with a3 = "negu a0"
+ * This code is nearly identical to the aligned code above
+ * but only the destination (not the source) gets aligned
+ * so we need to do partial loads of the source followed
+ * by normal stores to the destination (once we have aligned
+ * the destination).
+ */
+
+L(unaligned):
+ andi a3,a3,(NSIZE-1) /* copy a3 bytes to align a0/a1 */
+ beqz a3,L(ua_chk16w) /* if a3=0, it is already aligned */
+ PTR_SUBU a2,a2,a3 /* a2 is the remining bytes count */
+
+ C_LDHI v1,UNIT(0)(a1)
+ C_LDLO v1,UNITM1(1)(a1)
+ PTR_ADDU a1,a1,a3
+ C_STHI v1,UNIT(0)(a0)
+ PTR_ADDU a0,a0,a3
+
+/*
+ * Now the destination (but not the source) is aligned
+ * Set a2 to count how many bytes we have to copy after all the 64/128 byte
+ * chunks are copied and a3 to the dst pointer after all the 64/128 byte
+ * chunks have been copied. We will loop, incrementing a0 and a1 until a0
+ * equals a3.
+ */
-L(shift):
- subu a3, zero, a0 # Src and Dest unaligned
- andi a3, 0x3 # (unoptimized case...)
- beq a3, zero, L(shft1)
- subu a2, a3 # a2 = bytes left
- LWHI t0, 0(a1) # Take care of first odd part
- LWLO t0, 3(a1)
- addu a1, a3
- SWHI t0, 0(a0)
- addu a0, a3
-L(shft1):
- andi t0, a2, 0x3
- subu a3, a2, t0
- addu a3, a1
-L(shfth):
- LWHI t1, 0(a1) # Limp through, word by word
- LWLO t1, 3(a1)
- addiu a0, 4
- addiu a1, 4
- bne a1, a3, L(shfth)
- sw t1, -4(a0)
- b L(last8) # Handle anything which may be left
- move a2, t0
+L(ua_chk16w):
+ andi t8,a2,NSIZEDMASK /* any whole 64-byte/128-byte chunks? */
+ beq a2,t8,L(ua_chkw) /* if a2==t8, no 64-byte/128-byte chunks */
+ PTR_SUBU a3,a2,t8 /* subtract from a2 the reminder */
+ PTR_ADDU a3,a0,a3 /* Now a3 is the final dst after loop */
+#if (PREFETCH_STORE_HINT == PREFETCH_HINT_PREPAREFORSTORE)
+ PTR_ADDU t0,a0,a2 /* t0 is the "past the end" address */
+ PTR_SUBU t9,t0,PREFETCH_LIMIT /* t9 is the "last safe pref" address */
+#endif
+ PREFETCH_FOR_LOAD (0, a1)
+ PREFETCH_FOR_LOAD (1, a1)
+ PREFETCH_FOR_LOAD (2, a1)
+ PREFETCH_FOR_STORE (1, a0)
+#if (PREFETCH_STORE_HINT == PREFETCH_HINT_PREPAREFORSTORE)
+ sltu v1,t9,a0
+ bgtz v1,L(ua_loop16w) /* skip prefetch for too short arrays */
+ nop
+#endif
+ PREFETCH_FOR_STORE (2, a0)
+L(ua_loop16w):
+ PREFETCH_FOR_LOAD (3, a1)
+ C_LDHI t0,UNIT(0)(a1)
+ C_LDLO t0,UNITM1(1)(a1)
+ C_LDHI t1,UNIT(1)(a1)
+#if (PREFETCH_STORE_HINT == PREFETCH_HINT_PREPAREFORSTORE)
+ bgtz v1,L(ua_skip_pref30_96)
+#endif
+ C_LDLO t1,UNITM1(2)(a1)
+ PREFETCH_FOR_STORE (3, a0)
+L(ua_skip_pref30_96):
+ C_LDHI REG2,UNIT(2)(a1)
+ C_LDLO REG2,UNITM1(3)(a1)
+ C_LDHI REG3,UNIT(3)(a1)
+ C_LDLO REG3,UNITM1(4)(a1)
+ C_LDHI REG4,UNIT(4)(a1)
+ C_LDLO REG4,UNITM1(5)(a1)
+ C_LDHI REG5,UNIT(5)(a1)
+ C_LDLO REG5,UNITM1(6)(a1)
+ C_LDHI REG6,UNIT(6)(a1)
+ C_LDLO REG6,UNITM1(7)(a1)
+ C_LDHI REG7,UNIT(7)(a1)
+ C_LDLO REG7,UNITM1(8)(a1)
+ PREFETCH_FOR_LOAD (4, a1)
+ C_ST t0,UNIT(0)(a0)
+ C_ST t1,UNIT(1)(a0)
+ C_ST REG2,UNIT(2)(a0)
+ C_ST REG3,UNIT(3)(a0)
+ C_ST REG4,UNIT(4)(a0)
+ C_ST REG5,UNIT(5)(a0)
+ C_ST REG6,UNIT(6)(a0)
+ C_ST REG7,UNIT(7)(a0)
+ C_LDHI t0,UNIT(8)(a1)
+ C_LDLO t0,UNITM1(9)(a1)
+ C_LDHI t1,UNIT(9)(a1)
+#if (PREFETCH_STORE_HINT == PREFETCH_HINT_PREPAREFORSTORE)
+ bgtz v1,L(ua_skip_pref30_128)
+#endif
+ C_LDLO t1,UNITM1(10)(a1)
+ PREFETCH_FOR_STORE (4, a0)
+L(ua_skip_pref30_128):
+ C_LDHI REG2,UNIT(10)(a1)
+ C_LDLO REG2,UNITM1(11)(a1)
+ C_LDHI REG3,UNIT(11)(a1)
+ C_LDLO REG3,UNITM1(12)(a1)
+ C_LDHI REG4,UNIT(12)(a1)
+ C_LDLO REG4,UNITM1(13)(a1)
+ C_LDHI REG5,UNIT(13)(a1)
+ C_LDLO REG5,UNITM1(14)(a1)
+ C_LDHI REG6,UNIT(14)(a1)
+ C_LDLO REG6,UNITM1(15)(a1)
+ C_LDHI REG7,UNIT(15)(a1)
+ C_LDLO REG7,UNITM1(16)(a1)
+ PREFETCH_FOR_LOAD (5, a1)
+ C_ST t0,UNIT(8)(a0)
+ C_ST t1,UNIT(9)(a0)
+ C_ST REG2,UNIT(10)(a0)
+ C_ST REG3,UNIT(11)(a0)
+ C_ST REG4,UNIT(12)(a0)
+ C_ST REG5,UNIT(13)(a0)
+ C_ST REG6,UNIT(14)(a0)
+ C_ST REG7,UNIT(15)(a0)
+ PTR_ADDIU a0,a0,UNIT(16) /* adding 64/128 to dest */
+#if (PREFETCH_STORE_HINT == PREFETCH_HINT_PREPAREFORSTORE)
+ sltu v1,t9,a0
+#endif
+ bne a0,a3,L(ua_loop16w)
+ PTR_ADDIU a1,a1,UNIT(16) /* adding 64/128 to src */
+ move a2,t8
+
+/* Here we have src and dest word-aligned but less than 64-bytes or
+ * 128 bytes to go. Check for a 32(64) byte chunk and copy if if there
+ * is one. Otherwise jump down to L(ua_chk1w) to handle the tail end of
+ * the copy. */
+
+L(ua_chkw):
+ PREFETCH_FOR_LOAD (0, a1)
+ andi t8,a2,NSIZEMASK /* Is there a 32-byte/64-byte chunk. */
+ /* t8 is the reminder count past 32-bytes */
+ beq a2,t8,L(ua_chk1w) /* When a2=t8, no 32-byte chunk */
+ nop
+ C_LDHI t0,UNIT(0)(a1)
+ C_LDLO t0,UNITM1(1)(a1)
+ C_LDHI t1,UNIT(1)(a1)
+ C_LDLO t1,UNITM1(2)(a1)
+ C_LDHI REG2,UNIT(2)(a1)
+ C_LDLO REG2,UNITM1(3)(a1)
+ C_LDHI REG3,UNIT(3)(a1)
+ C_LDLO REG3,UNITM1(4)(a1)
+ C_LDHI REG4,UNIT(4)(a1)
+ C_LDLO REG4,UNITM1(5)(a1)
+ C_LDHI REG5,UNIT(5)(a1)
+ C_LDLO REG5,UNITM1(6)(a1)
+ C_LDHI REG6,UNIT(6)(a1)
+ C_LDLO REG6,UNITM1(7)(a1)
+ C_LDHI REG7,UNIT(7)(a1)
+ C_LDLO REG7,UNITM1(8)(a1)
+ PTR_ADDIU a1,a1,UNIT(8)
+ C_ST t0,UNIT(0)(a0)
+ C_ST t1,UNIT(1)(a0)
+ C_ST REG2,UNIT(2)(a0)
+ C_ST REG3,UNIT(3)(a0)
+ C_ST REG4,UNIT(4)(a0)
+ C_ST REG5,UNIT(5)(a0)
+ C_ST REG6,UNIT(6)(a0)
+ C_ST REG7,UNIT(7)(a0)
+ PTR_ADDIU a0,a0,UNIT(8)
+/*
+ * Here we have less then 32(64) bytes to copy. Set up for a loop to
+ * copy one word (or double word) at a time.
+ */
+L(ua_chk1w):
+ andi a2,t8,(NSIZE-1) /* a2 is the reminder past one (d)word chunks */
+ beq a2,t8,L(ua_smallCopy)
+ PTR_SUBU a3,t8,a2 /* a3 is count of bytes in one (d)word chunks */
+ PTR_ADDU a3,a0,a3 /* a3 is the dst address after loop */
+
+/* copying in words (4-byte or 8-byte chunks) */
+L(ua_wordCopy_loop):
+ C_LDHI v1,UNIT(0)(a1)
+ C_LDLO v1,UNITM1(1)(a1)
+ PTR_ADDIU a1,a1,UNIT(1)
+ PTR_ADDIU a0,a0,UNIT(1)
+ bne a0,a3,L(ua_wordCopy_loop)
+ C_ST v1,UNIT(-1)(a0)
+
+/* Copy the last 8 (or 16) bytes */
+L(ua_smallCopy):
+ beqz a2,L(leave)
+ PTR_ADDU a3,a0,a2 /* a3 is the last dst address */
+L(ua_smallCopy_loop):
+ lb v1,0(a1)
+ PTR_ADDIU a1,a1,1
+ PTR_ADDIU a0,a0,1
+ bne a0,a3,L(ua_smallCopy_loop)
+ sb v1,-1(a0)
+
+ j ra
+ nop
+
+ .set at
.set reorder
-END (memcpy)
-libc_hidden_builtin_def (memcpy)
+END(MEMCPY_NAME)
+#ifdef _LIBC
+libc_hidden_builtin_def (MEMCPY_NAME)
+#endif