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/* i80386 rshift, lshift
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* Copyright (C) 1998 Free Software Foundation, Inc.
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* Copyright (C) 1992, 1994 Free Software Foundation, Inc.
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* This file is part of GNUPG.
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* GNUPG is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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* GNUPG is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
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* Note: This code is heavily based on the GNU MP Library.
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* Actually it's the same code with only minor changes in the
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* way the data is stored; this is to support the abstraction
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* of an optional secure memory allocation which may be used
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* to avoid revealing of sensitive data due to paging etc.
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* The GNU MP Library itself is published under the LGPL;
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* however I decided to publish this code under the plain GPL.
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#include "asm-syntax.h"
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* mpihelp_lshift( mpi_ptr_t wp, (sp + 4)
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* mpi_ptr_t up, (sp + 8)
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* mpi_size_t usize, (sp + 12)
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* unsigned cnt) (sp + 16)
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.globl C_SYMBOL_NAME(mpihelp_lshift)
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C_SYMBOL_NAME(mpihelp_lshift:)
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movl 16(%esp),%edi /* res_ptr */
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movl 20(%esp),%esi /* s_ptr */
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movl 24(%esp),%edx /* size */
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movl 28(%esp),%ecx /* cnt */
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subl $4,%esi /* adjust s_ptr */
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movl (%esi,%edx,4),%ebx /* read most significant limb */
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shldl %cl,%ebx,%eax /* compute carry limb */
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pushl %eax /* push carry limb onto stack */
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jnz L1 /* enter loop in the middle */
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Loop: movl (%esi,%edx,4),%ebx /* load next lower limb */
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shldl %cl,%ebx,%eax /* compute result limb */
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movl %eax,(%edi,%edx,4) /* store it */
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L1: movl (%esi,%edx,4),%eax
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movl %ebx,(%edi,%edx,4)
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shll %cl,%eax /* compute least significant limb */
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movl %eax,(%edi) /* store it */
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popl %eax /* pop carry limb */
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Lend: shll %cl,%ebx /* compute least significant limb */
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movl %ebx,(%edi) /* store it */
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* mpihelp_rshift( mpi_ptr_t wp, (sp + 4)
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* mpi_ptr_t up, (sp + 8)
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* mpi_size_t usize, (sp + 12)
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* unsigned cnt) (sp + 16)
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.globl C_SYMBOL_NAME(mpihelp_rshift)
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C_SYMBOL_NAME(mpihelp_rshift:)
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movl 16(%esp),%edi /* wp */
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movl 20(%esp),%esi /* up */
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movl 24(%esp),%edx /* usize */
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movl 28(%esp),%ecx /* cnt */
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leal -4(%edi,%edx,4),%edi
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leal (%esi,%edx,4),%esi
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movl (%esi,%edx,4),%ebx /* read least significant limb */
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shrdl %cl,%ebx,%eax /* compute carry limb */
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pushl %eax /* push carry limb onto stack */
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jnz L2 /* enter loop in the middle */
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Loop2: movl (%esi,%edx,4),%ebx /* load next higher limb */
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shrdl %cl,%ebx,%eax /* compute result limb */
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movl %eax,(%edi,%edx,4) /* store it */
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L2: movl (%esi,%edx,4),%eax
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movl %ebx,(%edi,%edx,4)
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shrl %cl,%eax /* compute most significant limb */
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movl %eax,(%edi) /* store it */
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popl %eax /* pop carry limb */
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Lend2: shrl %cl,%ebx /* compute most significant limb */
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movl %ebx,(%edi) /* store it */
added
removed
mpi/i386/mpih-shift.S
