power7-optimized mempcpy

1 files changed, 471 insertions, 0 deletions

diff --git a/sysdeps/powerpc/powerpc32/power7/mempcpy.S b/sysdeps/powerpc/powerpc32/power7/mempcpy.S
new file mode 100644
index 0000000..5e05256
--- /dev/null
+++ b/sysdeps/powerpc/powerpc32/power7/mempcpy.S
@@ -0,0 +1,471 @@
+/* Optimized mempcpy implementation for POWER7.
+   Copyright (C) 2010 Free Software Foundation, Inc.
+   Contributed by Luis Machado <luisgpm@br.ibm.com>.
+   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] __mempcpy (__ptr_t dst [r3], __ptr_t src [r4], size_t len [r5]);
+	Returns 'dst' + 'len'.  */
+
+	.machine  power7
+EALIGN (BP_SYM (__mempcpy), 5, 0)
+	CALL_MCOUNT
+
+	stwu	1,-32(1)
+	cfi_adjust_cfa_offset(32)
+	stw	30,20(1)
+	cfi_offset(30,(20-32))
+	stw	31,24(1)
+	mr	30,3
+	cmplwi	cr1,5,31
+	neg	0,3
+	cfi_offset(31,-8)
+	ble	cr1,L(copy_LT_32)  /* If move < 32 bytes use short move
+					code.  */
+
+	andi.	11,3,7	      /* Check alignment of DST.  */
+	clrlwi	10,4,29	      /* Check alignment of SRC.  */
+	cmplw	cr6,10,11     /* SRC and DST alignments match?  */
+	mr	12,4
+	mr	31,5
+	bne	cr6,L(copy_GE_32_unaligned)
+
+	srwi	9,5,3	      /* Number of full quadwords remaining.  */
+
+	beq	L(copy_GE_32_aligned_cont)
+
+	clrlwi	0,0,29
+	mtcrf	0x01,0
+	subf	31,0,5
+
+	/* Get the SRC aligned to 8 bytes.  */
+
+1:	bf	31,2f
+	lbz	6,0(12)
+	addi	12,12,1
+	stb	6,0(3)
+	addi	3,3,1
+2:	bf	30,4f
+	lhz	6,0(12)
+	addi	12,12,2
+	sth	6,0(3)
+	addi	3,3,2
+4:	bf	29,0f
+	lwz	6,0(12)
+	addi	12,12,4
+	stw	6,0(3)
+	addi	3,3,4
+0:
+	clrlwi	10,12,29      /* Check alignment of SRC again.  */
+	srwi	9,31,3	      /* Number of full doublewords remaining.  */
+
+L(copy_GE_32_aligned_cont):
+
+	clrlwi	11,31,29
+	mtcrf	0x01,9
+
+	srwi	8,31,5
+	cmplwi	cr1,9,4
+	cmplwi	cr6,11,0
+	mr	11,12
+
+	/* Copy 1~3 doublewords so the main loop starts
+	at a multiple of 32 bytes.  */
+
+	bf	30,1f
+	lfd	6,0(12)
+	lfd	7,8(12)
+	addi	11,12,16
+	mtctr	8
+	stfd	6,0(3)
+	stfd	7,8(3)
+	addi	10,3,16
+	bf	31,4f
+	lfd	0,16(12)
+	stfd	0,16(3)
+	blt	cr1,3f
+	addi	11,12,24
+	addi	10,3,24
+	b	4f
+
+	.align	4
+1:	/* Copy 1 doubleword and set the counter.  */
+	mr	10,3
+	mtctr	8
+	bf	31,4f
+	lfd	6,0(12)
+	addi	11,12,8
+	stfd	6,0(3)
+	addi	10,3,8
+
+	.align	4
+4:	/* Main aligned copy loop. Copies 32-bytes at a time.  */
+	lfd	6,0(11)
+	lfd	7,8(11)
+	lfd	8,16(11)
+	lfd	0,24(11)
+	addi	11,11,32
+
+	stfd	6,0(10)
+	stfd	7,8(10)
+	stfd	8,16(10)
+	stfd	0,24(10)
+	addi	10,10,32
+	bdnz	4b
+3:
+
+	/* Check for tail bytes.  */
+
+	clrrwi	0,31,3
+	mtcrf	0x01,31
+	beq	cr6,0f
+
+.L9:
+	add	3,3,0
+	add	12,12,0
+
+	/*  At this point we have a tail of 0-7 bytes and we know that the
+	destination is doubleword-aligned.  */
+4:	/* Copy 4 bytes.  */
+	bf	29,2f
+
+	lwz	6,0(12)
+	addi	12,12,4
+	stw	6,0(3)
+	addi	3,3,4
+2:	/* Copy 2 bytes.  */
+	bf	30,1f
+
+	lhz	6,0(12)
+	addi	12,12,2
+	sth	6,0(3)
+	addi	3,3,2
+1:	/* Copy 1 byte.  */
+	bf	31,0f
+
+	lbz	6,0(12)
+	stb	6,0(3)
+0:	/* Return DST + LEN pointer.  */
+	add	3,30,5
+	lwz	30,20(1)
+	lwz	31,24(1)
+	addi	1,1,32
+	blr
+
+	/* Handle copies of 0~31 bytes.  */
+	.align	4
+L(copy_LT_32):
+	cmplwi	cr6,5,8
+	mr	12,4
+	mtcrf	0x01,5
+	ble	cr6,L(copy_LE_8)
+
+	/* At least 9 bytes to go.  */
+	neg	8,4
+	clrrwi	11,4,2
+	andi.	0,8,3
+	cmplwi	cr1,5,16
+	mr	10,5
+	beq	L(copy_LT_32_aligned)
+
+	/* Force 4-bytes alignment for SRC.  */
+	mtocrf  0x01,0
+	subf	10,0,5
+2:	bf	30,1f
+
+	lhz	6,0(12)
+	addi	12,12,2
+	sth	6,0(3)
+	addi	3,3,2
+1:	bf	31,L(end_4bytes_alignment)
+
+	lbz	6,0(12)
+	addi	12,12,1
+	stb	6,0(3)
+	addi	3,3,1
+
+	.align	4
+L(end_4bytes_alignment):
+	cmplwi	cr1,10,16
+	mtcrf	0x01,10
+
+L(copy_LT_32_aligned):
+	/* At least 6 bytes to go, and SRC is word-aligned.  */
+	blt	cr1,8f
+
+	/* Copy 16 bytes.  */
+	lwz	6,0(12)
+	lwz	7,4(12)
+	stw	6,0(3)
+	lwz	8,8(12)
+	stw	7,4(3)
+	lwz	6,12(12)
+	addi	12,12,16
+	stw	8,8(3)
+	stw	6,12(3)
+	addi	3,3,16
+8:	/* Copy 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:	/* Copy 4 bytes.  */
+	bf	29,2f
+
+	lwz	6,0(12)
+	addi	12,12,4
+	stw	6,0(3)
+	addi	3,3,4
+2:	/* Copy 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)
+
+	/* Return DST + LEN pointer.  */
+	add	3,30,5
+	lwz	30,20(1)
+	addi	1,1,32
+	blr
+
+	.align	4
+1:	/* Copy 1 byte.  */
+	bf	31,0f
+
+	lbz	6,0(12)
+	stb	6,0(3)
+0:	/* Return DST + LEN pointer.  */
+	add	3,30,5
+	lwz	30,20(1)
+	addi	1,1,32
+	blr
+
+	/* Handles copies of 0~8 bytes.  */
+	.align	4
+L(copy_LE_8):
+	bne	cr6,4f
+
+	/* Though we could've used lfd/stfd here, they are still
+	slow for unaligned cases.  */
+
+	lwz	6,0(4)
+	lwz	7,4(4)
+	stw	6,0(3)
+	stw	7,4(3)
+
+	/* Return DST + LEN pointer.  */
+	add	3,30,5
+	lwz	30,20(1)
+	addi	1,1,32
+	blr
+
+	.align	4
+4:	/* Copies 4~7 bytes.  */
+	bf	29,2b
+
+	lwz	6,0(4)
+	stw	6,0(3)
+	bf	30,5f
+	lhz	7,4(4)
+	sth	7,4(3)
+	bf	31,0f
+	lbz	8,6(4)
+	stb	8,6(3)
+
+	/* Return DST + LEN pointer.  */
+	add	3,30,5
+	lwz	30,20(1)
+	addi	1,1,32
+	blr
+
+	.align	4
+5:	/* Copy 1 byte.  */
+	bf	31,0f
+
+	lbz	6,4(4)
+	stb	6,4(3)
+
+0:	/* Return DST + LEN pointer.  */
+	add	3,30,5
+	lwz	30,20(1)
+	addi	1,1,32
+	blr
+
+	/* Handle copies of 32+ bytes where DST is aligned (to quadword) but
+	SRC is not. Use aligned quadword loads from SRC, shifted to realign
+	the data, allowing for aligned DST stores.  */
+	.align	4
+L(copy_GE_32_unaligned):
+	andi.	11,3,15	      /* Check alignment of DST.  */
+	clrlwi	0,0,28	      /* Number of bytes until the 1st
+				 quadword of DST.  */
+	srwi	9,5,4	      /* Number of full quadwords remaining.  */
+
+	beq	L(copy_GE_32_unaligned_cont)
+
+	/* SRC is not quadword aligned, get it aligned.  */
+
+	mtcrf	0x01,0
+	subf	31,0,5
+
+	/* Vector instructions work best when proper alignment (16-bytes)
+	is present.  Move 0~15 bytes as needed to get DST quadword-aligned.  */
+1:	/* Copy 1 byte.  */
+	bf	31,2f
+
+	lbz	6,0(12)
+	addi	12,12,1
+	stb	6,0(3)
+	addi	3,3,1
+2:	/* Copy 2 bytes.  */
+	bf		30,4f
+
+	lhz	6,0(12)
+	addi	12,12,2
+	sth	6,0(3)
+	addi	3,3,2
+4:	/* Copy 4 bytes.  */
+	bf	29,8f
+
+	lwz	6,0(12)
+	addi	12,12,4
+	stw	6,0(3)
+	addi	3,3,4
+8:	/* Copy 8 bytes.  */
+	bf	28,0f
+
+	lfd	6,0(12)
+	addi	12,12,8
+	stfd	6,0(3)
+	addi	3,3,8
+0:
+	clrlwi	10,12,28      /* Check alignment of SRC.  */
+	srwi	9,31,4	      /* Number of full quadwords remaining.  */
+
+	/* The proper alignment is present, it is OK to copy the bytes now.  */
+L(copy_GE_32_unaligned_cont):
+
+	/* Setup two indexes to speed up the indexed vector operations.  */
+	clrlwi	11,31,28
+	li	6,16	      /* Index for 16-bytes offsets.  */
+	li	7,32	      /* Index for 32-bytes offsets.  */
+	cmplwi	cr1,11,0
+	srwi	8,31,5	      /* Setup the loop counter.  */
+	mr	10,3
+	mr	11,12
+	mtcrf	0x01,9
+	cmplwi	cr6,9,1
+	lvsl	5,0,12
+	lvx	3,0,12
+	bf	31,L(setup_unaligned_loop)
+
+	/* Copy another 16 bytes to align to 32-bytes due to the loop .  */
+	lvx	4,12,6
+	vperm	6,3,4,5
+	addi	11,12,16
+	addi	10,3,16
+	stvx	6,0,3
+	vor	3,4,4
+
+L(setup_unaligned_loop):
+	mtctr	8
+	ble	cr6,L(end_unaligned_loop)
+
+	/* Copy 32 bytes at a time using vector instructions.  */
+	.align	4
+L(unaligned_loop):
+
+	/* Note: vr6/vr10 may contain data that was already copied,
+	but in order to get proper alignment, we may have to copy
+	some portions again. This is faster than having unaligned
+	vector instructions though.  */
+
+	lvx	4,11,6	      /* vr4 = r11+16.  */
+	vperm	6,3,4,5	      /* Merge the correctly-aligned portions
+				 of vr3/vr4 into vr6.  */
+	lvx	3,11,7	      /* vr3 = r11+32.  */
+	vperm	10,4,3,5      /* Merge the correctly-aligned portions
+				 of vr3/vr4 into vr10.  */
+	addi	11,11,32
+	stvx	6,0,10
+	stvx	10,10,6
+	addi	10,10,32
+
+	bdnz	L(unaligned_loop)
+
+	.align	4
+L(end_unaligned_loop):
+
+	/* Check for tail bytes.  */
+	clrrwi	0,31,4
+	mtcrf	0x01,31
+	beq	cr1,0f
+
+	add	3,3,0
+	add	12,12,0
+
+	/*  We have 1~15 tail bytes to copy, and DST is quadword aligned.  */
+8:	/* Copy 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:	/* Copy 4 bytes.  */
+	bf	29,2f
+
+	lwz	6,0(12)
+	addi	12,12,4
+	stw	6,0(3)
+	addi	3,3,4
+2:	/* Copy 2~3 bytes.  */
+	bf	30,1f
+
+	lhz	6,0(12)
+	addi	12,12,2
+	sth	6,0(3)
+	addi	3,3,2
+1:	/* Copy 1 byte.  */
+	bf	31,0f
+
+	lbz	6,0(12)
+	stb	6,0(3)
+0:	/* Return DST + LEN pointer.  */
+	add	3,30,5
+	lwz	30,20(1)
+	lwz	31,24(1)
+	addi	1,1,32
+	blr
+
+END (BP_SYM (__mempcpy))
+libc_hidden_def (BP_SYM (__mempcpy))
+weak_alias (BP_SYM (__mempcpy), BP_SYM (mempcpy))
+libc_hidden_builtin_def (mempcpy)