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Diffstat (limited to 'mpi/i386/mpih-sub1.S')
| -rw-r--r-- | mpi/i386/mpih-sub1.S | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/mpi/i386/mpih-sub1.S b/mpi/i386/mpih-sub1.S new file mode 100644 index 00000000..c0345083 --- /dev/null +++ b/mpi/i386/mpih-sub1.S @@ -0,0 +1,118 @@ +/* i80386 sub_n -- Sub two limb vectors of the same length > 0 and store + * sum in a third limb vector. + * Copyright (C) 1992, 1994, 1995 Free Software Foundation, Inc. + * Copyright (c) 1997 by Werner Koch (dd9jn) + * + * This file is part of G10. + * + * G10 is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * G10 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 General Public License for more details. + * + * You should have received a copy of the GNU 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. + * The GNU MP Library itself is published under the LGPL; + * however I decided to publish this code under the plain GPL. + */ + + +#include "sysdep.h" +#include "asm-syntax.h" + + +/******************* + * mpi_limb_t + * mpihelp_sub_n( mpi_ptr_t res_ptr, (sp + 4) + * mpi_ptr_t s1_ptr, (sp + 8) + * mpi_ptr_t s2_ptr, (sp + 12) + * mpi_size_t size) (sp + 16) + */ + + +.text + ALIGN (3) + .globl C_SYMBOL_NAME(mpihelp_sub_n) +C_SYMBOL_NAME(mpihelp_sub_n:) + pushl %edi + pushl %esi + + movl 12(%esp),%edi /* res_ptr */ + movl 16(%esp),%esi /* s1_ptr */ + movl 20(%esp),%edx /* s2_ptr */ + movl 24(%esp),%ecx /* size */ + + movl %ecx,%eax + shrl $3,%ecx /* compute count for unrolled loop */ + negl %eax + andl $7,%eax /* get index where to start loop */ + jz Loop /* necessary special case for 0 */ + incl %ecx /* adjust loop count */ + shll $2,%eax /* adjustment for pointers... */ + subl %eax,%edi /* ... since they are offset ... */ + subl %eax,%esi /* ... by a constant when we ... */ + subl %eax,%edx /* ... enter the loop */ + shrl $2,%eax /* restore previous value */ +#ifdef PIC +/* Calculate start address in loop for PIC. Due to limitations in some + assemblers, Loop-L0-3 cannot be put into the leal */ + call L0 +L0: leal (%eax,%eax,8),%eax + addl (%esp),%eax + addl $(Loop-L0-3),%eax + addl $4,%esp +#else +/* Calculate start address in loop for non-PIC. */ + leal (Loop - 3)(%eax,%eax,8),%eax +#endif + jmp *%eax /* jump into loop */ + ALIGN (3) +Loop: movl (%esi),%eax + sbbl (%edx),%eax + movl %eax,(%edi) + movl 4(%esi),%eax + sbbl 4(%edx),%eax + movl %eax,4(%edi) + movl 8(%esi),%eax + sbbl 8(%edx),%eax + movl %eax,8(%edi) + movl 12(%esi),%eax + sbbl 12(%edx),%eax + movl %eax,12(%edi) + movl 16(%esi),%eax + sbbl 16(%edx),%eax + movl %eax,16(%edi) + movl 20(%esi),%eax + sbbl 20(%edx),%eax + movl %eax,20(%edi) + movl 24(%esi),%eax + sbbl 24(%edx),%eax + movl %eax,24(%edi) + movl 28(%esi),%eax + sbbl 28(%edx),%eax + movl %eax,28(%edi) + leal 32(%edi),%edi + leal 32(%esi),%esi + leal 32(%edx),%edx + decl %ecx + jnz Loop + + sbbl %eax,%eax + negl %eax + + popl %esi + popl %edi + ret + |