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-rw-r--r--sysdeps/powerpc/powerpc32/lshift.S131
1 files changed, 131 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc32/lshift.S b/sysdeps/powerpc/powerpc32/lshift.S
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+++ b/sysdeps/powerpc/powerpc32/lshift.S
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+/* Shift a limb left, low level routine.
+   Copyright (C) 1996, 1997, 1999, 2000 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., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <sysdep.h>
+#include <bp-sym.h>
+#include <bp-asm.h>
+
+/* mp_limb_t mpn_lshift (mp_ptr wp, mp_srcptr up, mp_size_t usize,
+  			 unsigned int cnt)  */
+
+EALIGN (BP_SYM (__mpn_lshift), 3, 0)
+
+#if __BOUNDED_POINTERS__
+	slwi r10,r5,2		/* convert limbs to bytes */
+	CHECK_BOUNDS_BOTH_WIDE (r3, r8, r9, r10)
+	CHECK_BOUNDS_BOTH_WIDE (r4, r8, r9, r10)
+#endif
+	mtctr	r5		# copy size into CTR
+	cmplwi	cr0,r5,16	# is size < 16
+	slwi	r0,r5,2
+	add	r7,r3,r0	# make r7 point at end of res
+	add	r4,r4,r0	# make r4 point at end of s1
+	lwzu	r11,-4(r4)	# load first s1 limb
+	subfic	r8,r6,32
+	srw	r3,r11,r8	# compute function return value
+	bge	cr0,L(big)	# branch if size >= 16
+
+	bdz	L(end1)
+
+L(0):	lwzu	r10,-4(r4)
+	slw	r9,r11,r6
+	srw	r12,r10,r8
+	or	r9,r9,r12
+	stwu	r9,-4(r7)
+	bdz	L(end2)
+	lwzu	r11,-4(r4)
+	slw	r9,r10,r6
+	srw	r12,r11,r8
+	or	r9,r9,r12
+	stwu	r9,-4(r7)
+	bdnz	L(0)
+
+L(end1):slw	r0,r11,r6
+	stw	r0,-4(r7)
+	blr
+
+
+/* Guaranteed not to succeed.  */
+L(boom): tweq    r0,r0
+
+/* We imitate a case statement, by using (yuk!) fixed-length code chunks,
+   of size 4*12 bytes.  We have to do this (or something) to make this PIC.  */
+L(big):	mflr    r9
+	bltl-   cr0,L(boom)	# Never taken, only used to set LR.
+	slwi    r10,r6,4
+	mflr    r12
+	add     r10,r12,r10
+	slwi	r8,r6,5
+	add     r10,r8,r10
+	mtctr   r10
+	addi	r5,r5,-1
+	mtlr    r9
+	bctr
+
+L(end2):slw	r0,r10,r6
+	stw	r0,-4(r7)
+	blr
+
+#define DO_LSHIFT(n) \
+	mtctr	r5;							\
+L(n):	lwzu	r10,-4(r4);						\
+	slwi	r9,r11,n;						\
+	inslwi	r9,r10,n,32-n;					\
+	stwu	r9,-4(r7);						\
+	bdz-	L(end2);						\
+	lwzu	r11,-4(r4);						\
+	slwi	r9,r10,n;						\
+	inslwi	r9,r11,n,32-n;					\
+	stwu	r9,-4(r7);						\
+	bdnz	L(n);							\
+	b	L(end1)
+
+	DO_LSHIFT(1)
+	DO_LSHIFT(2)
+	DO_LSHIFT(3)
+	DO_LSHIFT(4)
+	DO_LSHIFT(5)
+	DO_LSHIFT(6)
+	DO_LSHIFT(7)
+	DO_LSHIFT(8)
+	DO_LSHIFT(9)
+	DO_LSHIFT(10)
+	DO_LSHIFT(11)
+	DO_LSHIFT(12)
+	DO_LSHIFT(13)
+	DO_LSHIFT(14)
+	DO_LSHIFT(15)
+	DO_LSHIFT(16)
+	DO_LSHIFT(17)
+	DO_LSHIFT(18)
+	DO_LSHIFT(19)
+	DO_LSHIFT(20)
+	DO_LSHIFT(21)
+	DO_LSHIFT(22)
+	DO_LSHIFT(23)
+	DO_LSHIFT(24)
+	DO_LSHIFT(25)
+	DO_LSHIFT(26)
+	DO_LSHIFT(27)
+	DO_LSHIFT(28)
+	DO_LSHIFT(29)
+	DO_LSHIFT(30)
+	DO_LSHIFT(31)
+
+END (BP_SYM (__mpn_lshift))