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Diffstat (limited to 'libotr/libgcrypt-1.8.7/mpi/i586/mpih-lshift.S')
| -rw-r--r-- | libotr/libgcrypt-1.8.7/mpi/i586/mpih-lshift.S | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/libotr/libgcrypt-1.8.7/mpi/i586/mpih-lshift.S b/libotr/libgcrypt-1.8.7/mpi/i586/mpih-lshift.S new file mode 100644 index 0000000..9d25fe9 --- /dev/null +++ b/libotr/libgcrypt-1.8.7/mpi/i586/mpih-lshift.S @@ -0,0 +1,229 @@ +/* i80586 lshift + * + * Copyright (C) 1992, 1994, 1998, + * 2001, 2002 Free Software Foundation, Inc. + * + * This file is part of Libgcrypt. + * + * Libgcrypt 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. + * + * Libgcrypt 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 this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + * + * Note: This code is heavily based on the GNU MP Library. + * Actually it's the same code with only minor changes in the + * way the data is stored; this is to support the abstraction + * of an optional secure memory allocation which may be used + * to avoid revealing of sensitive data due to paging etc. + */ + + +#include "sysdep.h" +#include "asm-syntax.h" + + +/******************* + * mpi_limb_t + * _gcry_mpih_lshift( mpi_ptr_t wp, (sp + 4) + * mpi_ptr_t up, (sp + 8) + * mpi_size_t usize, (sp + 12) + * unsigned cnt) (sp + 16) + */ + +.text + ALIGN (3) + .globl C_SYMBOL_NAME(_gcry_mpih_lshift) +C_SYMBOL_NAME(_gcry_mpih_lshift:) + + pushl %edi + pushl %esi + pushl %ebx + pushl %ebp + + movl 20(%esp),%edi /* res_ptr */ + movl 24(%esp),%esi /* s_ptr */ + movl 28(%esp),%ebp /* size */ + movl 32(%esp),%ecx /* cnt */ + +/* We can use faster code for shift-by-1 under certain conditions. */ + cmp $1,%ecx + jne Lnormal + leal 4(%esi),%eax + cmpl %edi,%eax + jnc Lspecial /* jump if s_ptr + 1 >= res_ptr */ + leal (%esi,%ebp,4),%eax + cmpl %eax,%edi + jnc Lspecial /* jump if res_ptr >= s_ptr + size */ + +Lnormal: + leal -4(%edi,%ebp,4),%edi + leal -4(%esi,%ebp,4),%esi + + movl (%esi),%edx + subl $4,%esi + xorl %eax,%eax + shldl %cl,%edx,%eax /* compute carry limb */ + pushl %eax /* push carry limb onto stack */ + + decl %ebp + pushl %ebp + shrl $3,%ebp + jz Lend + + movl (%edi),%eax /* fetch destination cache line */ + + ALIGN (2) +Loop: movl -28(%edi),%eax /* fetch destination cache line */ + movl %edx,%ebx + + movl (%esi),%eax + movl -4(%esi),%edx + shldl %cl,%eax,%ebx + shldl %cl,%edx,%eax + movl %ebx,(%edi) + movl %eax,-4(%edi) + + movl -8(%esi),%ebx + movl -12(%esi),%eax + shldl %cl,%ebx,%edx + shldl %cl,%eax,%ebx + movl %edx,-8(%edi) + movl %ebx,-12(%edi) + + movl -16(%esi),%edx + movl -20(%esi),%ebx + shldl %cl,%edx,%eax + shldl %cl,%ebx,%edx + movl %eax,-16(%edi) + movl %edx,-20(%edi) + + movl -24(%esi),%eax + movl -28(%esi),%edx + shldl %cl,%eax,%ebx + shldl %cl,%edx,%eax + movl %ebx,-24(%edi) + movl %eax,-28(%edi) + + subl $32,%esi + subl $32,%edi + decl %ebp + jnz Loop + +Lend: popl %ebp + andl $7,%ebp + jz Lend2 +Loop2: movl (%esi),%eax + shldl %cl,%eax,%edx + movl %edx,(%edi) + movl %eax,%edx + subl $4,%esi + subl $4,%edi + decl %ebp + jnz Loop2 + +Lend2: shll %cl,%edx /* compute least significant limb */ + movl %edx,(%edi) /* store it */ + + popl %eax /* pop carry limb */ + + popl %ebp + popl %ebx + popl %esi + popl %edi + ret + +/* We loop from least significant end of the arrays, which is only + permissable if the source and destination don't overlap, since the + function is documented to work for overlapping source and destination. +*/ + +Lspecial: + movl (%esi),%edx + addl $4,%esi + + decl %ebp + pushl %ebp + shrl $3,%ebp + + addl %edx,%edx + incl %ebp + decl %ebp + jz LLend + + movl (%edi),%eax /* fetch destination cache line */ + + ALIGN (2) +LLoop: movl 28(%edi),%eax /* fetch destination cache line */ + movl %edx,%ebx + + movl (%esi),%eax + movl 4(%esi),%edx + adcl %eax,%eax + movl %ebx,(%edi) + adcl %edx,%edx + movl %eax,4(%edi) + + movl 8(%esi),%ebx + movl 12(%esi),%eax + adcl %ebx,%ebx + movl %edx,8(%edi) + adcl %eax,%eax + movl %ebx,12(%edi) + + movl 16(%esi),%edx + movl 20(%esi),%ebx + adcl %edx,%edx + movl %eax,16(%edi) + adcl %ebx,%ebx + movl %edx,20(%edi) + + movl 24(%esi),%eax + movl 28(%esi),%edx + adcl %eax,%eax + movl %ebx,24(%edi) + adcl %edx,%edx + movl %eax,28(%edi) + + leal 32(%esi),%esi /* use leal not to clobber carry */ + leal 32(%edi),%edi + decl %ebp + jnz LLoop + +LLend: popl %ebp + sbbl %eax,%eax /* save carry in %eax */ + andl $7,%ebp + jz LLend2 + addl %eax,%eax /* restore carry from eax */ +LLoop2: movl %edx,%ebx + movl (%esi),%edx + adcl %edx,%edx + movl %ebx,(%edi) + + leal 4(%esi),%esi /* use leal not to clobber carry */ + leal 4(%edi),%edi + decl %ebp + jnz LLoop2 + + jmp LL1 +LLend2: addl %eax,%eax /* restore carry from eax */ +LL1: movl %edx,(%edi) /* store last limb */ + + sbbl %eax,%eax + negl %eax + + popl %ebp + popl %ebx + popl %esi + popl %edi + ret + + |