Replace MIPS specific memcpy.S/memset.S with version from glibc/newlib.

These MIPS specific versions of memcpy.S and memset.S are faster than
the current ones and match what is in newlib and glibc.  They also have
support for the mips32r6 and mips64r6 architectures.

Signed-off-by: Steve Ellcey <sellcey@imgtec.com>

1 files changed, 395 insertions, 121 deletions

diff --git a/libc/string/mips/memset.S b/libc/string/mips/memset.S
index 26b25985d..ef8ab0b13 100644
--- a/libc/string/mips/memset.S
+++ b/libc/string/mips/memset.S
@@ -1,6 +1,5 @@
-/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
+/* Copyright (C) 2013-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
-   Contributed by Hartvig Ekner <hartvige@mips.com>, 2002.
 
    The GNU C Library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
@@ -13,145 +12,420 @@
    Lesser General Public License for more details.
 
    You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
+   License along with the GNU C Library.  If not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <features.h>
-#include <sysdep.h>
-#include <endian.h>
+#ifdef ANDROID_CHANGES
+# include "machine/asm.h"
+# include "machine/regdef.h"
+# define PREFETCH_STORE_HINT PREFETCH_HINT_PREPAREFORSTORE
+#elif _LIBC
+# include <sysdep.h>
+# include <regdef.h>
+# include <sys/asm.h>
+# define PREFETCH_STORE_HINT PREFETCH_HINT_PREPAREFORSTORE
+#elif defined _COMPILING_NEWLIB
+# include "machine/asm.h"
+# include "machine/regdef.h"
+# define PREFETCH_STORE_HINT PREFETCH_HINT_PREPAREFORSTORE
+#else
+# include <regdef.h>
+# include <sys/asm.h>
+#endif
+
+/* Check to see if the MIPS architecture we are compiling for supports
+   prefetching.  */
+
+#if (__mips == 4) || (__mips == 5) || (__mips == 32) || (__mips == 64)
+# ifndef DISABLE_PREFETCH
+#  define USE_PREFETCH
+# endif
+#endif
+
+#if defined(_MIPS_SIM) && ((_MIPS_SIM == _ABI64) || (_MIPS_SIM == _ABIN32))
+# ifndef DISABLE_DOUBLE
+#  define USE_DOUBLE
+# endif
+#endif
+
+#ifndef USE_DOUBLE
+# ifndef DISABLE_DOUBLE_ALIGN
+#  define DOUBLE_ALIGN
+# 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
 
-/* void *memset(void *s, int c, size_t n).  */
+/* New R6 instructions that may not be in asm.h.  */
+#ifndef PTR_LSA
+# if _MIPS_SIM == _ABI64
+#  define PTR_LSA        dlsa
+# else
+#  define PTR_LSA        lsa
+# endif
+#endif
+
+/* 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.
+
+   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
+   less than MAX_PREFETCH_SIZE bytes and if the cache line is larger it will
+   not work correctly.  */
+
+#ifdef USE_PREFETCH
+# define PREFETCH_HINT_STORE		1
+# define PREFETCH_HINT_STORE_STREAMED	5
+# define PREFETCH_HINT_STORE_RETAINED	7
+# 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
+
+/* 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_STORE(chunk, reg) \
+    pref PREFETCH_STORE_HINT, (chunk)*64(reg); \
+    pref PREFETCH_STORE_HINT, ((chunk)*64)+32(reg)
+# else
+#  define PREFETCH_CHUNK 32
+#  define PREFETCH_FOR_STORE(chunk, reg) \
+    pref PREFETCH_STORE_HINT, (chunk)*32(reg)
+# endif
 
-#ifdef __mips64
+/* MAX_PREFETCH_SIZE is the maximum size of a prefetch, it must not be less
+   than PREFETCH_CHUNK, the assumed size of each prefetch.  If the real size
+   of a prefetch is greater than MAX_PREFETCH_SIZE and the PREPAREFORSTORE
+   hint is used, the code will not work correctly.  If PREPAREFORSTORE is not
+   used than MAX_PREFETCH_SIZE does not matter.  */
+# define MAX_PREFETCH_SIZE 128
+/* PREFETCH_LIMIT is set based on the fact that we never use an offset greater
+   than 5 on a STORE prefetch and that a single prefetch can never be larger
+   than MAX_PREFETCH_SIZE.  We add the extra 32 when USE_DOUBLE is set because
+   we actually do two prefetches in that case, one 32 bytes after the other.  */
+# ifdef USE_DOUBLE
+#  define PREFETCH_LIMIT (5 * PREFETCH_CHUNK) + 32 + MAX_PREFETCH_SIZE
+# else
+#  define PREFETCH_LIMIT (5 * PREFETCH_CHUNK) + MAX_PREFETCH_SIZE
+# endif
 
-#include <sys/asm.h>
+# if (PREFETCH_STORE_HINT == PREFETCH_HINT_PREPAREFORSTORE) \
+    && ((PREFETCH_CHUNK * 4) < MAX_PREFETCH_SIZE)
+/* We cannot handle this because the initial prefetches may fetch bytes that
+   are before the buffer being copied.  We start copies with an offset
+   of 4 so avoid this situation when using PREPAREFORSTORE.  */
+#  error "PREFETCH_CHUNK is too large and/or MAX_PREFETCH_SIZE is too small."
+# endif
+#else /* USE_PREFETCH not defined */
+# define PREFETCH_FOR_STORE(offset, reg)
+#endif
+
+#if __mips_isa_rev > 5
+# if (PREFETCH_STORE_HINT == PREFETCH_HINT_PREPAREFORSTORE)
+#  undef PREFETCH_STORE_HINT
+#  define PREFETCH_STORE_HINT PREFETCH_HINT_STORE_STREAMED
+# endif
+# define R6_CODE
+#endif
 
-#if __BYTE_ORDER == __BIG_ENDIAN
-# define SDHI	sdl		/* high part is left in big-endian	*/
+/* Allow the routine to be named something else if desired.  */
+#ifndef MEMSET_NAME
+# define MEMSET_NAME memset
+#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
+# ifdef __MIPSEB
+#  define C_STHI	sdl	/* high part is left in big-endian	*/
+# else
+#  define C_STHI	sdr	/* high part is right in little-endian	*/
+# endif
 #else
-# define SDHI	sdr		/* high part is right in little-endian	*/
+# define C_ST	sw
+# ifdef __MIPSEB
+#  define C_STHI	swl	/* high part is left in big-endian	*/
+# else
+#  define C_STHI	swr	/* high part is right in little-endian	*/
+# endif
 #endif
 
-ENTRY (memset)
-	.set	noreorder
+/* Bookkeeping values for 32 vs. 64 bit mode.  */
+#ifdef USE_DOUBLE
+# define NSIZE 8
+# define NSIZEMASK 0x3f
+# define NSIZEDMASK 0x7f
+#else
+# define NSIZE 4
+# define NSIZEMASK 0x1f
+# define NSIZEDMASK 0x3f
+#endif
+#define UNIT(unit) ((unit)*NSIZE)
+#define UNITM1(unit) (((unit)*NSIZE)-1)
 
-	slti	ta1, a2, 16		# Less than 16?
-	bne	ta1, zero, L(last16)
-	move	v0, a0			# Setup exit value before too late
-
-	beq	a1, zero, L(ueven)	# If zero pattern, no need to extend
-	andi	a1, 0xff		# Avoid problems with bogus arguments
-	dsll	ta0, a1, 8
-	or	a1, ta0
-	dsll	ta0, a1, 16
-	or	a1, ta0			# a1 is now pattern in full word
-	dsll	ta0, a1, 32
-	or	a1, ta0			# a1 is now pattern in double word
-
-L(ueven):
-	PTR_SUBU ta0, zero, a0		# Unaligned address?
-	andi	ta0, 0x7
-	beq	ta0, zero, L(chkw)
-	PTR_SUBU a2, ta0
-	SDHI	a1, 0(a0)		# Yes, handle first unaligned part
-	PTR_ADDU a0, ta0		# Now both a0 and a2 are updated
+#ifdef ANDROID_CHANGES
+LEAF(MEMSET_NAME,0)
+#else
+LEAF(MEMSET_NAME)
+#endif
 
-L(chkw):
-	andi	ta0, a2, 0xf		# Enough left for one loop iteration?
-	beq	ta0, a2, L(chkl)
-	PTR_SUBU a3, a2, ta0
-	PTR_ADDU a3, a0			# a3 is last loop address +1
-	move	a2, ta0			# a2 is now # of bytes left after loop
-L(loopw):
-	PTR_ADDIU a0, 16		# Handle 2 dwords pr. iteration
-	sd	a1, -16(a0)
-	bne	a0, a3, L(loopw)
-	sd	a1,  -8(a0)
-
-L(chkl):
-	andi	ta0, a2, 0x8		# Check if there is at least a double
-	beq	ta0, zero, L(last16)	#  word remaining after the loop
-	PTR_SUBU a2, ta0
-	sd	a1, 0(a0)		# Yes...
-	PTR_ADDIU a0, 8
-
-L(last16):
-	blez	a2, L(exit)		# Handle last 16 bytes (if cnt>0)
-	PTR_ADDU a3, a2, a0		# a3 is last address +1
-L(lst16l):
-	PTR_ADDIU a0, 1
-	bne	a0, a3, L(lst16l)
-	sb	a1, -1(a0)
-L(exit):
-	j	ra			# Bye, bye
+	.set	nomips16
+	.set	noreorder
+/* If the size is less than 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 memset value is not zero, we copy it to all the bytes in a 32 or 64
+   bit word.  */
+	beq	a1,zero,L(set0)		/* If memset value is zero no smear  */
+	PTR_SUBU a3,zero,a0
 	nop
 
-	.set	reorder
-END (memset)
+	/* smear byte into 32 or 64 bit word */
+#if ((__mips == 64) || (__mips == 32)) && (__mips_isa_rev >= 2)
+# ifdef USE_DOUBLE
+	dins	a1, a1, 8, 8        /* Replicate fill byte into half-word.  */
+	dins	a1, a1, 16, 16      /* Replicate fill byte into word.       */
+	dins	a1, a1, 32, 32      /* Replicate fill byte into dbl word.   */
+# else
+	ins	a1, a1, 8, 8        /* Replicate fill byte into half-word.  */
+	ins	a1, a1, 16, 16      /* Replicate fill byte into word.       */
+# endif
+#else
+# ifdef USE_DOUBLE
+        and     a1,0xff
+	dsll	t2,a1,8
+	or	a1,t2
+	dsll	t2,a1,16
+	or	a1,t2
+	dsll	t2,a1,32
+	or	a1,t2
+# else
+        and     a1,0xff
+	sll	t2,a1,8
+	or	a1,t2
+	sll	t2,a1,16
+	or	a1,t2
+# endif
+#endif
+
+/* If the destination address is not aligned do a partial store to get it
+   aligned.  If it is already aligned just jump to L(aligned).  */
+L(set0):
+#ifndef R6_CODE
+	andi	t2,a3,(NSIZE-1)		/* word-unaligned address?          */
+	beq	t2,zero,L(aligned)	/* t2 is the unalignment count      */
+	PTR_SUBU a2,a2,t2
+	C_STHI	a1,0(a0)
+	PTR_ADDU a0,a0,t2
+#else /* R6_CODE */
+	andi	t2,a0,(NSIZE-1)
+	lapc	t9,L(atable)
+	PTR_LSA	t9,t2,t9,2
+	jrc	t9
+L(atable):
+	bc	L(aligned)
+# ifdef USE_DOUBLE
+	bc	L(lb7)
+	bc	L(lb6)
+	bc	L(lb5)
+	bc	L(lb4)
+# endif
+	bc	L(lb3)
+	bc	L(lb2)
+	bc	L(lb1)
+L(lb7):
+	sb	a1,6(a0)
+L(lb6):
+	sb	a1,5(a0)
+L(lb5):
+	sb	a1,4(a0)
+L(lb4):
+	sb	a1,3(a0)
+L(lb3):
+	sb	a1,2(a0)
+L(lb2):
+	sb	a1,1(a0)
+L(lb1):
+	sb	a1,0(a0)
+
+	li	t9,NSIZE
+	subu	t2,t9,t2
+	PTR_SUBU a2,a2,t2
+	PTR_ADDU a0,a0,t2
+#endif /* R6_CODE */
+
+L(aligned):
+/* If USE_DOUBLE is not set we may still want to align the data on a 16
+   byte boundry instead of an 8 byte boundry to maximize the opportunity
+   of proAptiv chips to do memory bonding (combining two sequential 4
+   byte stores into one 8 byte store).  We know there are at least 4 bytes
+   left to store or we would have jumped to L(lastb) earlier in the code.  */
+#ifdef DOUBLE_ALIGN
+	andi	t2,a3,4
+	beq	t2,zero,L(double_aligned)
+	PTR_SUBU a2,a2,t2
+	sw	a1,0(a0)
+	PTR_ADDU a0,a0,t2
+L(double_aligned):
+#endif
 
-#else /* !__mips64 */
+/* Now the destination is aligned to (word or double word) aligned address
+   Set a2 to count how many bytes we have to copy after all the 64/128 byte
+   chunks are copied and a3 to the dest pointer after all the 64/128 byte
+   chunks have been copied.  We will loop, incrementing a0 until it equals
+   a3.  */
+	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 */
 
-#if __BYTE_ORDER == __BIG_ENDIAN
-# define SWHI	swl		/* high part is left in big-endian	*/
+/* 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 defined(USE_PREFETCH) \
+    && (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
+#if defined(USE_PREFETCH) \
+    && (PREFETCH_STORE_HINT != PREFETCH_HINT_PREPAREFORSTORE)
+	PREFETCH_FOR_STORE (1, a0)
+	PREFETCH_FOR_STORE (2, a0)
+	PREFETCH_FOR_STORE (3, a0)
+#endif
+
+L(loop16w):
+#if defined(USE_PREFETCH) \
+    && (PREFETCH_STORE_HINT == PREFETCH_HINT_PREPAREFORSTORE)
+	sltu	v1,t9,a0		/* If a0 > t9 don't use next prefetch */
+	bgtz	v1,L(skip_pref)
+	nop
+#endif
+#ifdef R6_CODE
+	PREFETCH_FOR_STORE (2, a0)
 #else
-# define SWHI	swr		/* high part is right in little-endian	*/
+	PREFETCH_FOR_STORE (4, a0)
+	PREFETCH_FOR_STORE (5, a0)
 #endif
+L(skip_pref):
+	C_ST	a1,UNIT(0)(a0)
+	C_ST	a1,UNIT(1)(a0)
+	C_ST	a1,UNIT(2)(a0)
+	C_ST	a1,UNIT(3)(a0)
+	C_ST	a1,UNIT(4)(a0)
+	C_ST	a1,UNIT(5)(a0)
+	C_ST	a1,UNIT(6)(a0)
+	C_ST	a1,UNIT(7)(a0)
+	C_ST	a1,UNIT(8)(a0)
+	C_ST	a1,UNIT(9)(a0)
+	C_ST	a1,UNIT(10)(a0)
+	C_ST	a1,UNIT(11)(a0)
+	C_ST	a1,UNIT(12)(a0)
+	C_ST	a1,UNIT(13)(a0)
+	C_ST	a1,UNIT(14)(a0)
+	C_ST	a1,UNIT(15)(a0)
+	PTR_ADDIU a0,a0,UNIT(16)	/* adding 64/128 to dest */
+	bne	a0,a3,L(loop16w)
+	nop
+	move	a2,t8
 
-ENTRY (memset)
-	.set	noreorder
+/* Here we have 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):
+	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_ST	a1,UNIT(0)(a0)
+	C_ST	a1,UNIT(1)(a0)
+	C_ST	a1,UNIT(2)(a0)
+	C_ST	a1,UNIT(3)(a0)
+	C_ST	a1,UNIT(4)(a0)
+	C_ST	a1,UNIT(5)(a0)
+	C_ST	a1,UNIT(6)(a0)
+	C_ST	a1,UNIT(7)(a0)
+	PTR_ADDIU a0,a0,UNIT(8)
+
+/* Here we have less than 32(64) bytes to set.  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 dest pointer after all the (d)word chunks have
+   been copied.  We will loop, incrementing a0 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 */
 
-	slti	t1, a2, 8		# Less than 8?
-	bne	t1, zero, L(last8)
-	move	v0, a0			# Setup exit value before too late
-
-	beq	a1, zero, L(ueven)	# If zero pattern, no need to extend
-	andi	a1, 0xff		# Avoid problems with bogus arguments
-	sll	t0, a1, 8
-	or	a1, t0
-	sll	t0, a1, 16
-	or	a1, t0			# a1 is now pattern in full word
-
-L(ueven):	
-	subu	t0, zero, a0		# Unaligned address?
-	andi	t0, 0x3
-	beq	t0, zero, L(chkw)
-	subu	a2, t0
-	SWHI	a1, 0(a0)		# Yes, handle first unaligned part
-	addu	a0, t0			# Now both a0 and a2 are updated
-
-L(chkw):	
-	andi	t0, a2, 0x7		# Enough left for one loop iteration?
-	beq	t0, a2, L(chkl)
-	subu	a3, a2, t0
-	addu	a3, a0			# a3 is last loop address +1
-	move	a2, t0			# a2 is now # of bytes left after loop
-L(loopw):	
-	addiu	a0, 8			# Handle 2 words pr. iteration
-	sw	a1, -8(a0)
-	bne	a0, a3, L(loopw)
-	sw	a1, -4(a0)
-
-L(chkl):	
-	andi	t0, a2, 0x4		# Check if there is at least a full
-	beq	t0, zero, L(last8)	#  word remaining after the loop
-	subu	a2, t0
-	sw	a1, 0(a0)		# Yes...
-	addiu	a0, 4
-
-L(last8):	
-	blez	a2, L(exit)		# Handle last 8 bytes (if cnt>0)
-	addu	a3, a2, a0		# a3 is last address +1
-L(lst8l):	
-	addiu	a0, 1
-	bne	a0, a3, L(lst8l)
-	sb	a1, -1(a0)
-L(exit):	
-	j	ra			# Bye, bye
+/* copying in words (4-byte or 8 byte chunks) */
+L(wordCopy_loop):
+	PTR_ADDIU a0,a0,UNIT(1)
+	bne	a0,a3,L(wordCopy_loop)
+	C_ST	a1,UNIT(-1)(a0)
+
+/* 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):
+	PTR_ADDIU a0,a0,1
+	bne	a0,a3,L(lastbloop)
+	sb	a1,-1(a0)
+L(leave):
+	j	ra
 	nop
 
+	.set	at
 	.set	reorder
-END (memset)
-
-#endif /* !__mips64 */
+END(MEMSET_NAME)
+#ifndef ANDROID_CHANGES
+# ifdef _LIBC
+#  ifdef __UCLIBC__
+libc_hidden_def(MEMSET_NAME)
+#  else
+libc_hidden_builtin_def (MEMSET_NAME)
+#  endif
+# endif
+#endif
 
-libc_hidden_def(memset)