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-rw-r--r--sysdeps/powerpc/memset.S199
1 files changed, 199 insertions, 0 deletions
diff --git a/sysdeps/powerpc/memset.S b/sysdeps/powerpc/memset.S
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+/* Optimized memset implementation for PowerPC.
+   Copyright (C) 1997 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 Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <sysdep.h>
+
+EALIGN(memset,5,1)
+/* __ptr_t [r3] memset (__ptr_t s [r3], int c [r4], size_t n [r5]));
+   Returns 's'.
+
+   The memset is done in three sizes: byte (8 bits), word (32 bits),
+   cache line (256 bits). There is a special case for setting cache lines
+   to 0, to take advantage of the dcbz instruction.
+   r6:	current address we are storing at
+   r7:	number of bytes we are setting now (when aligning)  */
+
+/* take care of case for size <= 4  */
+	cmplwi %cr1,%r5,4
+	andi.  %r7,%r3,3
+	mr     %r6,%r3
+	ble-   %cr1,L(small)
+/* align to word boundary  */
+	cmplwi %cr5,%r5,31
+	rlwimi %r4,%r4,8,16,23
+	beq+   L(aligned)		# 8th instruction from .align
+	mtcrf  0x01,%r3
+	subfic %r7,%r7,4
+	add    %r6,%r6,%r7
+	sub    %r5,%r5,%r7
+	bf+    31,0f
+	stb    %r4,0(%r3)
+	bt     30,L(aligned)
+0:	sth    %r4,-2(%r6)		#  16th instruction from .align
+/* take care of case for size < 31 */
+L(aligned):
+	mtcrf  0x01,%r5
+	rlwimi %r4,%r4,16,0,15
+	ble    %cr5,L(medium)
+/* align to cache line boundary...  */
+	andi.  %r7,%r6,0x1C
+	subfic %r7,%r7,0x20
+	beq    L(caligned)
+	mtcrf  0x01,%r7
+	add    %r6,%r6,%r7
+	sub    %r5,%r5,%r7
+	cmplwi %cr1,%r7,0x10
+	mr     %r8,%r6
+	bf     28,1f
+	stw    %r4,-4(%r8)
+	stwu   %r4,-8(%r8)
+1:	blt    %cr1,2f
+	stw    %r4,-4(%r8)	# 32nd instruction from .align
+	stw    %r4,-8(%r8)
+	stw    %r4,-12(%r8)
+	stwu   %r4,-16(%r8)
+2:	bf     29,L(caligned)
+	stw    %r4,-4(%r8)
+/* now aligned to a cache line.  */
+L(caligned):
+	cmplwi %cr1,%r4,0
+	clrrwi. %r7,%r5,5
+	mtcrf  0x01,%r5		# 40th instruction from .align
+	beq    %cr1,L(zloopstart) # special case for clearing memory using dcbz
+	srwi   %r0,%r7,5
+	mtctr  %r0
+	beq    L(medium)	# we may not actually get to do a full line
+	clrlwi. %r5,%r5,27
+	add    %r6,%r6,%r7
+0:	li     %r8,-0x40
+	bdz    L(cloopdone)	# 48th instruction from .align
+
+3:	dcbz   %r8,%r6
+	stw    %r4,-4(%r6)
+	stw    %r4,-8(%r6)
+	stw    %r4,-12(%r6)
+	stw    %r4,-16(%r6)
+	nop			# let 601 fetch last 4 instructions of loop
+	stw    %r4,-20(%r6)
+	stw    %r4,-24(%r6)	# 56th instruction from .align
+	nop			# let 601 fetch first 8 instructions of loop
+	stw    %r4,-28(%r6)
+	stwu   %r4,-32(%r6)
+	bdnz   3b
+L(cloopdone):
+	stw    %r4,-4(%r6)
+	stw    %r4,-8(%r6)
+	stw    %r4,-12(%r6)
+	stw    %r4,-16(%r6)	# 64th instruction from .align
+	stw    %r4,-20(%r6)
+	cmplwi %cr1,%r5,16
+	stw    %r4,-24(%r6)
+	stw    %r4,-28(%r6)
+	stwu   %r4,-32(%r6)
+	beqlr
+	add    %r6,%r6,%r7
+	b      L(medium_tail2)	# 72nd instruction from .align
+
+	.align 5
+	nop
+/* Clear lines of memory in 128-byte chunks.  */
+L(zloopstart):
+	clrlwi %r5,%r5,27
+	mtcrf  0x02,%r7
+	srwi.  %r0,%r7,7
+	mtctr  %r0
+	li     %r7,0x20
+	li     %r8,-0x40
+	cmplwi %cr1,%r5,16	# 8
+	bf     26,0f
+	dcbz   0,%r6
+	addi   %r6,%r6,0x20
+0:	li     %r9,-0x20
+	bf     25,1f
+	dcbz   0,%r6
+	dcbz   %r7,%r6
+	addi   %r6,%r6,0x40	# 16
+1:	cmplwi %cr5,%r5,0
+	beq    L(medium)
+L(zloop):
+	dcbz   0,%r6
+	dcbz   %r7,%r6
+	addi   %r6,%r6,0x80
+	dcbz   %r8,%r6
+	dcbz   %r9,%r6
+	bdnz   L(zloop)
+	beqlr  %cr5
+	b      L(medium_tail2)
+
+	.align 5
+L(small):
+/* Memset of 4 bytes or less.  */
+	cmplwi %cr5,%r5,1
+	cmplwi %cr1,%r5,3
+	bltlr  %cr5
+	stb    %r4,0(%r6)
+	beqlr  %cr5
+	nop
+	stb    %r4,1(%r6)
+	bltlr  %cr1
+	stb    %r4,2(%r6)
+	beqlr  %cr1
+	nop
+	stb    %r4,3(%r6)
+	blr
+
+/* Memset of 0-31 bytes.  */
+	.align 5
+L(medium):
+	cmplwi %cr1,%r5,16
+L(medium_tail2):
+	add    %r6,%r6,%r5
+L(medium_tail):
+	bt-    31,L(medium_31t)
+	bt-    30,L(medium_30t)
+L(medium_30f):
+	bt-    29,L(medium_29t)
+L(medium_29f):
+	bge-   %cr1,L(medium_27t)
+	bflr-  28
+	stw    %r4,-4(%r6)		# 8th instruction from .align
+	stw    %r4,-8(%r6)
+	blr
+
+L(medium_31t):
+	stbu   %r4,-1(%r6)
+	bf-    30,L(medium_30f)
+L(medium_30t):
+	sthu   %r4,-2(%r6)
+	bf-    29,L(medium_29f)
+L(medium_29t):
+	stwu   %r4,-4(%r6)
+	blt-   %cr1,L(medium_27f)	# 16th instruction from .align
+L(medium_27t):
+	stw    %r4,-4(%r6)
+	stw    %r4,-8(%r6)
+	stw    %r4,-12(%r6)
+	stwu   %r4,-16(%r6)
+L(medium_27f):
+	bflr-  28
+L(medium_28t):
+	stw    %r4,-4(%r6)
+	stw    %r4,-8(%r6)
+	blr
+END(memset)