summary refs log tree commit diff
path: root/sysdeps/powerpc/rshift.S
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/powerpc/rshift.S')
-rw-r--r--sysdeps/powerpc/rshift.S56
1 files changed, 56 insertions, 0 deletions
diff --git a/sysdeps/powerpc/rshift.S b/sysdeps/powerpc/rshift.S
new file mode 100644
index 0000000000..eb1f562bed
--- /dev/null
+++ b/sysdeps/powerpc/rshift.S
@@ -0,0 +1,56 @@
+/* Shift a limb right, low level routine.
+   Copyright (C) 1995, 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>
+
+/* INPUT PARAMETERS
+   res_ptr	r3
+   s1_ptr	r4
+   size		r5
+   cnt		r6  */
+
+ENTRY(__mpn_rshift)
+	mtctr	5		# copy size into CTR
+	addi	7,3,-4		# move adjusted res_ptr to free return reg
+	subfic	8,6,32
+	lwz	11,0(4)		# load first s1 limb
+	slw	3,11,8		# compute function return value
+	bdz	1f
+
+0:	lwzu	10,4(4)
+	srw	9,11,6
+	slw	12,10,8
+	or	9,9,12
+	stwu	9,4(7)
+	bdz	2f
+	lwzu	11,4(4)
+	srw	9,10,6
+	slw	12,11,8
+	or	9,9,12
+	stwu	9,4(7)
+	bdnz	0b
+
+1:	srw	0,11,6
+	stw	0,4(7)
+	blr
+
+2:	srw	0,10,6
+	stw	0,4(7)
+	blr
+END(__mpn_rshift)