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-rw-r--r--ports/sysdeps/mips/memset.S84
1 files changed, 84 insertions, 0 deletions
diff --git a/ports/sysdeps/mips/memset.S b/ports/sysdeps/mips/memset.S
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+/* Copyright (C) 2002-2012 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
+   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, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+
+
+/* void *memset(void *s, int c, size_t n).  */
+
+#if __MIPSEB
+# define SWHI	swl		/* high part is left in big-endian	*/
+#else
+# define SWHI	swr		/* high part is right in little-endian	*/
+#endif
+
+ENTRY (memset)
+	.set	noreorder
+
+	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
+	nop
+
+	.set	reorder
+END (memset)
+libc_hidden_builtin_def (memset)