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authorJoseph Myers <joseph@codesourcery.com>2012-07-01 13:06:41 +0000
committerJoseph Myers <joseph@codesourcery.com>2012-07-01 13:06:41 +0000
commite64ac02c24b43659048622714afdc92fedf561fa (patch)
tree37162878b72d302de351788bec4c9360c9d55f1d /ports/sysdeps/m68k/m680x0/rshift.S
parenta20c2b3c87aebc7d4b090c622d36480263b80042 (diff)
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Move all files into ports/ subdirectory in preparation for merge with glibc glibc-2.16-ports-before-merge
Diffstat (limited to 'ports/sysdeps/m68k/m680x0/rshift.S')
-rw-r--r--ports/sysdeps/m68k/m680x0/rshift.S167
1 files changed, 167 insertions, 0 deletions
diff --git a/ports/sysdeps/m68k/m680x0/rshift.S b/ports/sysdeps/m68k/m680x0/rshift.S
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+/* mc68020 __mpn_rshift -- Shift right a low-level natural-number integer.
+
+Copyright (C) 1996, 1998, 2012 Free Software Foundation, Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP 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 MP 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 MP Library.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/*
+  INPUT PARAMETERS
+  res_ptr	(sp + 4)
+  s_ptr		(sp + 8)
+  s_size	(sp + 16)
+  cnt		(sp + 12)
+*/
+
+#include "sysdep.h"
+#include "asm-syntax.h"
+
+#define res_ptr a1
+#define s_ptr a0
+#define s_size d6
+#define cnt d4
+
+	TEXT
+ENTRY(__mpn_rshift)
+/* Save used registers on the stack.  */
+	moveml	R(d2)-R(d6)/R(a2),MEM_PREDEC(sp)
+	cfi_adjust_cfa_offset (6*4)
+	cfi_rel_offset (R(d2), 0)
+	cfi_rel_offset (R(d3), 4)
+	cfi_rel_offset (R(d4), 8)
+	cfi_rel_offset (R(d5), 12)
+	cfi_rel_offset (R(d6), 16)
+	cfi_rel_offset (R(a2), 20)
+
+/* Copy the arguments to registers.  */
+	movel	MEM_DISP(sp,28),R(res_ptr)
+	movel	MEM_DISP(sp,32),R(s_ptr)
+	movel	MEM_DISP(sp,36),R(s_size)
+	movel	MEM_DISP(sp,40),R(cnt)
+
+	moveql	#1,R(d5)
+	cmpl	R(d5),R(cnt)
+	bne	L(Lnormal)
+	cmpl	R(res_ptr),R(s_ptr)
+	bls	L(Lspecial)		/* jump if res_ptr >= s_ptr */
+#if (defined (__mc68020__) || defined (__NeXT__) || defined(mc68020))
+	lea	MEM_INDX1(res_ptr,s_size,l,4),R(a2)
+#else /* not mc68020 */
+	movel	R(s_size),R(d0)
+	asll	#2,R(d0)
+	lea	MEM_INDX(res_ptr,d0,l),R(a2)
+#endif
+	cmpl	R(s_ptr),R(a2)
+	bls	L(Lspecial)		/* jump if s_ptr >= res_ptr + s_size */
+
+L(Lnormal:)
+	moveql	#32,R(d5)
+	subl	R(cnt),R(d5)
+	movel	MEM_POSTINC(s_ptr),R(d2)
+	movel	R(d2),R(d0)
+	lsll	R(d5),R(d0)		/* compute carry limb */
+
+	lsrl	R(cnt),R(d2)
+	movel	R(d2),R(d1)
+	subql	#1,R(s_size)
+	beq	L(Lend)
+	lsrl	#1,R(s_size)
+	bcs	L(L1)
+	subql	#1,R(s_size)
+
+L(Loop:)
+	movel	MEM_POSTINC(s_ptr),R(d2)
+	movel	R(d2),R(d3)
+	lsll	R(d5),R(d3)
+	orl	R(d3),R(d1)
+	movel	R(d1),MEM_POSTINC(res_ptr)
+	lsrl	R(cnt),R(d2)
+L(L1:)
+	movel	MEM_POSTINC(s_ptr),R(d1)
+	movel	R(d1),R(d3)
+	lsll	R(d5),R(d3)
+	orl	R(d3),R(d2)
+	movel	R(d2),MEM_POSTINC(res_ptr)
+	lsrl	R(cnt),R(d1)
+
+	dbf	R(s_size),L(Loop)
+	subl	#0x10000,R(s_size)
+	bcc	L(Loop)
+
+L(Lend:)
+	movel	R(d1),MEM(res_ptr) /* store most significant limb */
+
+/* Restore used registers from stack frame.  */
+	moveml	MEM_POSTINC(sp),R(d2)-R(d6)/R(a2)
+	cfi_remember_state
+	cfi_adjust_cfa_offset (-6*4)
+	cfi_restore (R(d2))
+	cfi_restore (R(d3))
+	cfi_restore (R(d4))
+	cfi_restore (R(d5))
+	cfi_restore (R(d6))
+	cfi_restore (R(a2))
+	rts
+
+/* We loop from most significant end of the arrays, which is only
+   permissible if the source and destination don't overlap, since the
+   function is documented to work for overlapping source and destination.  */
+
+	cfi_restore_state
+L(Lspecial:)
+#if (defined (__mc68020__) || defined (__NeXT__) || defined(mc68020))
+	lea	MEM_INDX1(s_ptr,s_size,l,4),R(s_ptr)
+	lea	MEM_INDX1(res_ptr,s_size,l,4),R(res_ptr)
+#else /* not mc68000 */
+	movel	R(s_size),R(d0)
+	asll	#2,R(d0)
+	addl	R(s_size),R(s_ptr)
+	addl	R(s_size),R(res_ptr)
+#endif
+
+	clrl	R(d0)			/* initialize carry */
+	eorw	#1,R(s_size)
+	lsrl	#1,R(s_size)
+	bcc	L(LL1)
+	subql	#1,R(s_size)
+
+L(LLoop:)
+	movel	MEM_PREDEC(s_ptr),R(d2)
+	roxrl	#1,R(d2)
+	movel	R(d2),MEM_PREDEC(res_ptr)
+L(LL1:)
+	movel	MEM_PREDEC(s_ptr),R(d2)
+	roxrl	#1,R(d2)
+	movel	R(d2),MEM_PREDEC(res_ptr)
+
+	dbf	R(s_size),L(LLoop)
+	roxrl	#1,R(d0)		/* save cy in msb */
+	subl	#0x10000,R(s_size)
+	bcs	L(LLend)
+	addl	R(d0),R(d0)		/* restore cy */
+	bra	L(LLoop)
+
+L(LLend:)
+/* Restore used registers from stack frame.  */
+	moveml	MEM_POSTINC(sp),R(d2)-R(d6)/R(a2)
+	cfi_adjust_cfa_offset (-6*4)
+	cfi_restore (R(d2))
+	cfi_restore (R(d3))
+	cfi_restore (R(d4))
+	cfi_restore (R(d5))
+	cfi_restore (R(d6))
+	cfi_restore (R(a2))
+	rts
+END(__mpn_rshift)