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authorUlrich Drepper <drepper@redhat.com>2007-06-03 21:20:06 +0000
committerUlrich Drepper <drepper@redhat.com>2007-06-03 21:20:06 +0000
commit04067002e8c1be0c432bd608736750ca7459ec69 (patch)
tree1875d7b84026d0881df23845f768ecdd05b66c6d /sysdeps/powerpc/powerpc32/power4/memcpy.S
parentb03b0c292034392fbe98b96fd0b3b5cde6c1587c (diff)
downloadglibc-04067002e8c1be0c432bd608736750ca7459ec69.tar.gz
glibc-04067002e8c1be0c432bd608736750ca7459ec69.tar.xz
glibc-04067002e8c1be0c432bd608736750ca7459ec69.zip
* sysdeps/powerpc/powerpc32/970/fpu/Implies: New file.
	* sysdeps/powerpc/powerpc32/power5/fpu/Implies: New file.
	* sysdeps/powerpc/powerpc32/power5+/fpu/Implies: New file.
	* sysdeps/powerpc/powerpc32/power6/fpu/Implies: New file.
	* sysdeps/powerpc/powerpc32/power6x/fpu/Implies: New file.
	* sysdeps/powerpc/powerpc64/970/fpu/Implies: New file.
	* sysdeps/powerpc/powerpc64/power5/fpu/Implies: New file.
	* sysdeps/powerpc/powerpc64/power5+/fpu/Implies: New file.
	* sysdeps/powerpc/powerpc64/power6/fpu/Implies: New file.
	* sysdeps/powerpc/powerpc64/power6x/fpu/Implies: New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/970/fpu/Implies: New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/power4/fpu/Implies:
	New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/power5/fpu/Implies:
	New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/power5+/fpu/Implies:
	New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/power6/fpu/Implies:
	New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/power6x/fpu/Implies:
	New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/970/fpu/Implies: New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/power4/fpu/Implies:
	New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/power5/fpu/Implies:
	New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/power5+/fpu/Implies:
	New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/power6/fpu/Implies:
	New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/power6x/fpu/Implies:
	New file.

2007-05-31  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/powerpc64/fpu/s_llrint.S: Move.
	* sysdeps/powerpc/powerpc32/power4/fpu/s_llrint.S: To here.
	* sysdeps/powerpc/powerpc32/powerpc64/fpu/s_llrintf.S: Move.
	* sysdeps/powerpc/powerpc32/power4/fpu/s_llrintf.S: To here.
	* sysdeps/powerpc/powerpc32/powerpc64/fpu/s_llround.S: Move.
	* sysdeps/powerpc/powerpc32/power4/fpu/s_llround.S: To here.
	* sysdeps/powerpc/powerpc32/powerpc64/fpu/s_llroundf.S: Move.
	* sysdeps/powerpc/powerpc32/power4/fpu/s_llroundf.S: To here.

2007-05-22  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/power5+/fpu/s_round.S
	(LONG_DOUBLE_COMPAT): Specify correct version, GLIBC_2_1.
	* sysdeps/powerpc/powerpc32/power5+/fpu/s_trunc.S
	(LONG_DOUBLE_COMPAT): Specify correct version, GLIBC_2_1.
	* sysdeps/powerpc/powerpc64/power5+/fpu/s_round.S
	(LONG_DOUBLE_COMPAT): Specify correct version, GLIBC_2_1.
	* sysdeps/powerpc/powerpc64/power5+/fpu/s_trunc.S
	(LONG_DOUBLE_COMPAT): Specify correct version, GLIBC_2_1.

2007-05-21  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/power4/fpu/slowexp.c: New file.
	* sysdeps/powerpc/powerpc32/power4/fpu/w_sqrt.c: New file.
	* sysdeps/powerpc/powerpc64/power4/fpu/slowexp.c: New file.
	* sysdeps/powerpc/powerpc64/power4/fpu/w_sqrt.c: New file.

2007-03-15  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/powerpc64/fpu/s_llrint.S
	[LONG_DOUBLE_COMPAT]: Add compat_symbol for llrintl@@GLIBC_2_1.

2006-02-13  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/power6/fpu/s_llrint.S: New File
	* sysdeps/powerpc/powerpc32/power6/fpu/s_llrintf.S: New File
	* sysdeps/powerpc/powerpc32/power6/fpu/s_llround.S: New File
	* sysdeps/powerpc/powerpc32/power6/fpu/s_llroundf.S: New File

2006-10-20  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/power4/fpu/slowpow.c: New file.
	* sysdeps/powerpc/powerpc64/power4/fpu/slowpow.c: New file.

2006-10-03  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/powerpc64/fpu/s_llround.S: New file.
	* sysdeps/powerpc/powerpc32/powerpc64/fpu/s_llroundf.S: New file.

	* sysdeps/powerpc/powerpc32/powerpc64/fpu/Makefile: Moved.
	* sysdeps/powerpc/powerpc32/powerpc64/fpu/mpa.c: Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/Makefile: To here.
	* sysdeps/powerpc/powerpc32/power4/fpu/mpa.c: Likewise.

2006-09-29  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/power6x/fpu/s_lrint.S: New file.
	* sysdeps/powerpc/powerpc32/power6x/fpu/s_lround.S: New file.
	* sysdeps/powerpc/powerpc64/power6x/fpu/s_llrint.S: New file.
	* sysdeps/powerpc/powerpc64/power6x/fpu/s_llround.S: New file.

2006-09-28  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/power5+/fpu/s_llround.S: New file.
	* sysdeps/powerpc/powerpc32/power5+/fpu/s_llroundf.S: New file.
	* sysdeps/powerpc/powerpc32/power5+/fpu/s_lround.S: New file.
	* sysdeps/powerpc/powerpc32/power6x/fpu/Implies: New file.
	* sysdeps/powerpc/powerpc64/power5+/fpu/s_llround.S: New file.
	* sysdeps/powerpc/powerpc64/power6x/fpu/Implies: New file.

2006-08-31  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/powerpc64/fpu/Makefile: New file.
	* sysdeps/powerpc/powerpc32/powerpc64/fpu/mpa.c: New file.
	* sysdeps/powerpc/powerpc64/power4/fpu/Makefile: New file.
	* sysdeps/powerpc/powerpc64/power4/fpu/mpa.c: New file.

2006-06-15  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/power5+/fpu/s_ceil.S: New file.
	* sysdeps/powerpc/powerpc32/power5+/fpu/s_ceilf.S: New file.
	* sysdeps/powerpc/powerpc32/power5+/fpu/s_floor.S: New file.
	* sysdeps/powerpc/powerpc32/power5+/fpu/s_floorf.S: New file.
	* sysdeps/powerpc/powerpc32/power5+/fpu/s_round.S: New file.
	* sysdeps/powerpc/powerpc32/power5+/fpu/s_roundf.S: New file.
	* sysdeps/powerpc/powerpc32/power5+/fpu/s_trunc.S: New file.
	* sysdeps/powerpc/powerpc32/power5+/fpu/s_truncf.S: New file.
	* sysdeps/powerpc/powerpc64/power5+/fpu/s_ceil.S: New file.
	* sysdeps/powerpc/powerpc64/power5+/fpu/s_ceilf.S: New file.
	* sysdeps/powerpc/powerpc64/power5+/fpu/s_floor.S: New file.
	* sysdeps/powerpc/powerpc64/power5+/fpu/s_floorf.S: New file.
	* sysdeps/powerpc/powerpc64/power5+/fpu/s_round.S: New file.
	* sysdeps/powerpc/powerpc64/power5+/fpu/s_roundf.S: New file.
	* sysdeps/powerpc/powerpc64/power5+/fpu/s_trunc.S: New file.
	* sysdeps/powerpc/powerpc64/power5+/fpu/s_truncf.S: New file.

2006-03-20  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/powerpc64/fpu/s_llrint.S: New file.
	* sysdeps/powerpc/powerpc32/powerpc64/fpu/s_llrintf.S: New file.

2007-06-01  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/power6/memset.S: New file.
	* sysdeps/powerpc/powerpc64/power6/memset.S: New file.

2007-05-31  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/970/Implies: New file.
	* sysdeps/powerpc/powerpc32/power5/Implies: New file.
	* sysdeps/powerpc/powerpc32/power5+/Implies: New file.
	* sysdeps/powerpc/powerpc32/power6/Implies: New file.
	* sysdeps/powerpc/powerpc32/power6x/Implies: New file.
	* sysdeps/powerpc/powerpc64/970/Implies: New file.
	* sysdeps/powerpc/powerpc64/power5/Implies: New file.
	* sysdeps/powerpc/powerpc64/power5+/Implies: New file.
	* sysdeps/powerpc/powerpc64/power6/Implies: New file.
	* sysdeps/powerpc/powerpc64/power6x/Implies: New file.

2007-05-21  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/power4/memset.S: New file

2007-03-13  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc64/memcpy.S: Improve aligned loop to minimize
	branch miss-predicts. Ensure that cache line crossing does not impact
	dispatch grouping.

2006-12-13  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc64/power4/memcopy.h: Replace with include
	"../../powerpc32/power4/memcopy.h".
	* sysdeps/powerpc/powerpc64/power4/wordcopy.c: Replace with include
	"../../powerpc32/power4/wordcopy.c".

2006-10-03  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/powerpc64/Makefile: Moved.
	* sysdeps/powerpc/powerpc32/powerpc64/memcopy.h: Likewise.
	* sysdeps/powerpc/powerpc32/powerpc64/wordcopy.c: Likewise.
	* sysdeps/powerpc/powerpc32/power4/Makefile: To here.
	* sysdeps/powerpc/powerpc32/power4/memcopy.h: Likewise.
	* sysdeps/powerpc/powerpc32/power4/wordcopy.c: Likewise.

2006-09-10  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/power6/memcpy.S: New file.

2006-08-31  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/power6/wordcopy.c: New file.
	* sysdeps/powerpc/powerpc32/powerpc64/Makefile: New file.
	* sysdeps/powerpc/powerpc32/powerpc64/memcopy.h: New file.
	* sysdeps/powerpc/powerpc32/powerpc64/wordcopy.c: New file.
	* sysdeps/powerpc/powerpc64/power4/Makefile: New file.
	* sysdeps/powerpc/powerpc64/power4/memcopy.h: New file.
	* sysdeps/powerpc/powerpc64/power4/wordcopy.c: New file.
	* sysdeps/powerpc/powerpc64/power6/wordcopy.c: New file.

2006-07-06  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc64/power6/memcpy.S: New file.

2006-03-20  Steven Munroe  <sjmunroe@us.ibm.com>

	* sysdeps/powerpc/powerpc32/power4/memcmp.S: New file.
	* sysdeps/powerpc/powerpc32/power4/memcpy.S: New file.
	* sysdeps/powerpc/powerpc32/power4/memset.S: New file.
	* sysdeps/powerpc/powerpc32/power4/strncmp.S: New file.
	* sysdeps/powerpc/powerpc64/power4/memcmp.S: New file.
	* sysdeps/powerpc/powerpc64/power4/memcpy.S: New file.
	* sysdeps/powerpc/powerpc64/power4/strncmp.S: New file.
Diffstat (limited to 'sysdeps/powerpc/powerpc32/power4/memcpy.S')
-rw-r--r--sysdeps/powerpc/powerpc32/power4/memcpy.S425
1 files changed, 425 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc32/power4/memcpy.S b/sysdeps/powerpc/powerpc32/power4/memcpy.S
new file mode 100644
index 0000000000..c48db2f3df
--- /dev/null
+++ b/sysdeps/powerpc/powerpc32/power4/memcpy.S
@@ -0,0 +1,425 @@
+/* Optimized memcpy implementation for PowerPC32 on PowerPC64.
+   Copyright (C) 2003, 2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   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, write to the Free
+   Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA
+   02110-1301 USA.  */
+
+#include <sysdep.h>
+#include <bp-sym.h>
+#include <bp-asm.h>
+
+/* __ptr_t [r3] memcpy (__ptr_t dst [r3], __ptr_t src [r4], size_t len [r5]);
+   Returns 'dst'.
+
+   Memcpy handles short copies (< 32-bytes) using a binary move blocks 
+   (no loops) of lwz/stw.  The tail (remaining 1-3) bytes is handled 
+   with the appropriate combination of byte and halfword load/stores. 
+   There is minimal effort to optimize the alignment of short moves.  
+
+   Longer moves (>= 32-bytes) justify the effort to get at least the
+   destination word (4-byte) aligned.  Further optimization is
+   possible when both source and destination are word aligned.
+   Each case has an optimized unrolled loop.   */
+
+EALIGN (BP_SYM (memcpy), 5, 0)
+	CALL_MCOUNT
+
+    stwu  1,-32(1)
+    cfi_adjust_cfa_offset(32)
+    stw   30,20(1)
+    cfi_offset(30,(20-32))
+    mr    30,3
+    cmplwi cr1,5,31     
+    stw   31,24(1)
+    cfi_offset(31,(24-32))
+    neg   0,3
+    andi. 11,3,3	/* check alignment of dst.  */
+    clrlwi 0,0,30	/* Number of bytes until the 1st word of dst.  */
+    clrlwi 10,4,30	/* check alignment of src.  */
+    cmplwi cr6,5,8
+    ble-  cr1,.L2	/* If move < 32 bytes use short move code.  */
+    cmplw cr6,10,11  
+    mr    12,4
+    srwi  9,5,2		/* Number of full words remaining.  */
+    mtcrf 0x01,0
+    mr    31,5
+    beq   .L0
+  
+    subf  31,0,5
+  /* Move 0-3 bytes as needed to get the destination word aligned.  */
+1:  bf    31,2f
+    lbz   6,0(12)
+    addi  12,12,1
+    stb   6,0(3)
+    addi  3,3,1
+2:  bf    30,0f
+    lhz   6,0(12)
+    addi  12,12,2
+    sth   6,0(3)
+    addi  3,3,2
+0:
+    clrlwi 10,12,30	/* check alignment of src again.  */     
+    srwi  9,31,2	/* Number of full words remaining.  */
+    
+  /* Copy words from source to destination, assuming the destination is 
+     aligned on a word boundary.
+
+     At this point we know there are at least 25 bytes left (32-7) to copy.
+     The next step is to determine if the source is also word aligned. 
+     If not branch to the unaligned move code at .L6. which uses
+     a load, shift, store strategy.
+     
+     Otherwise source and destination are word aligned, and we can use
+     the optimized word copy loop.  */
+.L0:
+    clrlwi	11,31,30  /* calculate the number of tail bytes */
+    mtcrf 0x01,9
+    bne-  cr6,.L6   /* If source is not word aligned.  */
+
+  /* Move words where destination and source are word aligned.
+     Use an unrolled loop to copy 4 words (16-bytes) per iteration.
+     If the the copy is not an exact multiple of 16 bytes, 1-3 
+     words are copied as needed to set up the main loop.  After
+     the main loop exits there may be a tail of 1-3 bytes. These bytes are 
+     copied a halfword/byte at a time as needed to preserve alignment.  */
+
+    srwi  8,31,4    /* calculate the 16 byte loop count */
+    cmplwi	cr1,9,4
+    cmplwi	cr6,11,0
+    mr    11,12
+    
+    bf    30,1f
+    lwz   6,0(12)
+    lwz   7,4(12)
+    addi  11,12,8
+    mtctr 8
+    stw   6,0(3)
+    stw   7,4(3)
+    addi  10,3,8
+    bf    31,4f
+    lwz   0,8(12)
+    stw   0,8(3)    
+    blt   cr1,3f
+    addi  11,12,12
+    addi  10,3,12
+    b     4f
+    .align  4
+1:
+    mr    10,3
+    mtctr 8
+    bf    31,4f
+    lwz   6,0(12)
+    addi  11,12,4
+    stw   6,0(3)
+    addi  10,3,4
+    
+    .align  4
+4:
+    lwz   6,0(11)
+    lwz   7,4(11)
+    lwz   8,8(11)
+    lwz   0,12(11)
+    stw   6,0(10)
+    stw   7,4(10)
+    stw   8,8(10)
+    stw   0,12(10)
+    addi  11,11,16
+    addi  10,10,16
+    bdnz  4b
+3:  
+    clrrwi 0,31,2
+    mtcrf 0x01,31
+    beq   cr6,0f
+.L9:
+    add   3,3,0
+    add   12,12,0
+    
+/*  At this point we have a tail of 0-3 bytes and we know that the
+    destination is word aligned.  */
+2:  bf    30,1f
+    lhz   6,0(12)
+    addi  12,12,2
+    sth   6,0(3)
+    addi  3,3,2
+1:  bf    31,0f
+    lbz   6,0(12)
+    stb   6,0(3)
+0:
+  /* Return original dst pointer.  */
+    mr  3,30
+    lwz 30,20(1)
+    lwz 31,24(1)
+    addi 1,1,32
+    blr
+       
+/* Copy up to 31 bytes.  This is divided into two cases 0-8 bytes and 
+   9-31 bytes.  Each case is handled without loops, using binary 
+   (1,2,4,8) tests.  
+   
+   In the short (0-8 byte) case no attempt is made to force alignment
+   of either source or destination.  The hardware will handle the 
+   unaligned load/stores with small delays for crossing 32- 64-byte, and 
+   4096-byte boundaries. Since these short moves are unlikely to be
+   unaligned or cross these boundaries, the overhead to force 
+   alignment is not justified.
+   
+   The longer (9-31 byte) move is more likely to cross 32- or 64-byte
+   boundaries.  Since only loads are sensitive to the 32-/64-byte
+   boundaries it is more important to align the source than the 
+   destination.  If the source is not already word aligned, we first
+   move 1-3 bytes as needed.  While the destination and stores may 
+   still be unaligned, this is only an issue for page (4096 byte
+   boundary) crossing, which should be rare for these short moves.  
+   The hardware handles this case automatically with a small delay.  */ 
+   
+    .align  4
+.L2:
+    mtcrf 0x01,5
+    neg   8,4
+    clrrwi 11,4,2
+    andi. 0,8,3
+    ble   cr6,.LE8	/* Handle moves of 0-8 bytes.  */
+/* At least 9 bytes left.  Get the source word aligned.  */
+    cmplwi	cr1,5,16
+    mr    10,5
+    mr    12,4
+    cmplwi	cr6,0,2
+    beq   .L3	/* If the source is already word aligned skip this.  */
+/* Copy 1-3 bytes to get source address word aligned.  */
+    lwz   6,0(11)
+    subf  10,0,5
+    add   12,4,0
+    blt   cr6,5f
+    srwi  7,6,16
+    bgt	  cr6,3f
+    sth   6,0(3)
+    b     7f
+    .align  4
+3:
+    stb   7,0(3)
+    sth   6,1(3)
+    b     7f
+    .align  4
+5:
+    stb   6,0(3)
+7:
+    cmplwi	cr1,10,16
+    add   3,3,0
+    mtcrf 0x01,10
+    .align  4
+.L3:
+/* At least 6 bytes left and the source is word aligned.  */
+    blt   cr1,8f
+16: /* Move 16 bytes.  */
+    lwz   6,0(12)
+    lwz   7,4(12)
+    stw   6,0(3)
+    lwz   6,8(12)
+    stw   7,4(3)
+    lwz   7,12(12)
+    addi  12,12,16
+    stw   6,8(3)
+    stw   7,12(3)
+    addi  3,3,16
+8:  /* Move 8 bytes.  */
+    bf    28,4f
+    lwz   6,0(12)
+    lwz   7,4(12)
+    addi  12,12,8
+    stw   6,0(3)
+    stw   7,4(3)
+    addi  3,3,8
+4:  /* Move 4 bytes.  */
+    bf    29,2f
+    lwz   6,0(12)
+    addi  12,12,4
+    stw   6,0(3)
+    addi  3,3,4    
+2:  /* Move 2-3 bytes.  */
+    bf    30,1f
+    lhz   6,0(12)
+    sth   6,0(3) 
+    bf    31,0f
+    lbz   7,2(12)
+    stb   7,2(3)
+    mr    3,30
+    lwz   30,20(1)
+    addi  1,1,32
+    blr
+1:  /* Move 1 byte.  */
+    bf    31,0f
+    lbz   6,0(12)
+    stb   6,0(3)
+0:
+  /* Return original dst pointer.  */
+    mr   3,30
+    lwz  30,20(1)
+    addi 1,1,32
+    blr
+
+/* Special case to copy 0-8 bytes.  */
+    .align  4
+.LE8:
+    mr    12,4
+    bne   cr6,4f
+    lwz   6,0(4)
+    lwz   7,4(4)
+    stw   6,0(3)
+    stw   7,4(3)
+  /* Return original dst pointer.  */
+    mr    3,30
+    lwz   30,20(1)
+    addi  1,1,32
+    blr
+    .align  4
+4:  bf    29,2b
+    lwz   6,0(4)
+    stw   6,0(3)
+6:
+    bf    30,5f
+    lhz   7,4(4)
+    sth   7,4(3) 
+    bf    31,0f
+    lbz   8,6(4)
+    stb   8,6(3)
+    mr    3,30
+    lwz   30,20(1)
+    addi  1,1,32
+    blr
+    .align  4
+5:  
+    bf    31,0f
+    lbz   6,4(4)
+    stb   6,4(3)
+    .align  4
+0:
+  /* Return original dst pointer.  */
+    mr   3,30
+    lwz  30,20(1)
+    addi 1,1,32
+    blr
+
+    .align  4
+.L6:
+
+  /* Copy words where the destination is aligned but the source is
+     not.  Use aligned word loads from the source, shifted to realign
+     the data, to allow aligned destination stores.  
+     Use an unrolled loop to copy 4 words (16-bytes) per iteration.
+     A single word is retained for storing at loop exit to avoid walking
+     off the end of a page within the loop.
+     If the copy is not an exact multiple of 16 bytes, 1-3 
+     words are copied as needed to set up the main loop.  After
+     the main loop exits there may be a tail of 1-3 bytes. These bytes are 
+     copied a halfword/byte at a time as needed to preserve alignment.  */
+    
+
+    cmplwi  cr6,11,0  /* are there tail bytes left ? */
+    subf    5,10,12   /* back up src pointer to prev word alignment */
+    slwi    10,10,3   /* calculate number of bits to shift 1st word left */
+    addi    11,9,-1   /* we move one word after the loop */
+    srwi    8,11,2    /* calculate the 16 byte loop count */
+    lwz     6,0(5)    /* load 1st src word into R6 */
+    mr      4,3
+    lwz     7,4(5)    /* load 2nd src word into R7 */
+    mtcrf   0x01,11
+    subfic  9,10,32   /* number of bits to shift 2nd word right */
+    mtctr   8
+    bf      30,1f
+
+    /* there are at least two words to copy, so copy them */
+    slw   0,6,10  /* shift 1st src word to left align it in R0 */
+    srw   8,7,9   /* shift 2nd src word to right align it in R8 */
+    or    0,0,8   /* or them to get word to store */
+    lwz   6,8(5)  /* load the 3rd src word */
+    stw   0,0(4)  /* store the 1st dst word */
+    slw   0,7,10  /* now left align 2nd src word into R0 */
+    srw   8,6,9   /* shift 3rd src word to right align it in R8 */
+    or    0,0,8   /* or them to get word to store */
+    lwz   7,12(5)
+    stw   0,4(4)  /* store the 2nd dst word */
+    addi  4,4,8
+    addi  5,5,16
+    bf    31,4f
+    /* there is a third word to copy, so copy it */
+    slw   0,6,10  /* shift 3rd src word to left align it in R0 */
+    srw   8,7,9   /* shift 4th src word to right align it in R8 */
+    or    0,0,8   /* or them to get word to store */
+    stw   0,0(4)  /* store 3rd dst word */
+    mr    6,7
+    lwz   7,0(5)
+    addi  5,5,4
+    addi  4,4,4
+    b     4f
+    .align 4
+1:
+    slw     0,6,10  /* shift 1st src word to left align it in R0 */
+    srw     8,7,9   /* shift 2nd src word to right align it in R8 */
+    addi  5,5,8
+    or    0,0,8   /* or them to get word to store */
+    bf    31,4f
+    mr    6,7
+    lwz   7,0(5)
+    addi  5,5,4
+    stw   0,0(4)  /* store the 1st dst word */
+    addi  4,4,4
+
+    .align  4
+4:
+    /* copy 16 bytes at a time */
+    slw   0,6,10 
+    srw   8,7,9 
+    or    0,0,8
+    lwz   6,0(5)
+    stw   0,0(4)
+    slw   0,7,10
+    srw   8,6,9
+    or    0,0,8
+    lwz   7,4(5)
+    stw   0,4(4)
+    slw   0,6,10 
+    srw   8,7,9 
+    or    0,0,8
+    lwz   6,8(5)
+    stw   0,8(4)
+    slw   0,7,10
+    srw   8,6,9 
+    or    0,0,8
+    lwz   7,12(5)
+    stw   0,12(4)
+    addi  5,5,16
+    addi  4,4,16
+    bdnz+ 4b
+8:
+    /* calculate and store the final word */
+    slw   0,6,10 
+    srw   8,7,9 
+    or    0,0,8
+    stw   0,0(4)
+3:
+    clrrwi 0,31,2
+    mtcrf 0x01,31
+    bne   cr6,.L9	/* If the tail is 0 bytes we are done!  */
+
+  /* Return original dst pointer.  */
+    mr   3,30
+    lwz  30,20(1)
+    lwz  31,24(1)
+    addi 1,1,32
+    blr
+END (BP_SYM (memcpy))
+
+libc_hidden_builtin_def (memcpy)