| /* Pentium optimized __mpn_rshift -- |
| Copyright (C) 1992-2014 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; see the file COPYING.LIB. If not, |
| see <http://www.gnu.org/licenses/>. */ |
| |
| #include "sysdep.h" |
| #include "asm-syntax.h" |
| |
| #define PARMS 4+16 /* space for 4 saved regs */ |
| #define RES PARMS |
| #define S RES+4 |
| #define SIZE S+4 |
| #define CNT SIZE+4 |
| |
| .text |
| ENTRY (__mpn_rshift) |
| |
| pushl %edi |
| cfi_adjust_cfa_offset (4) |
| pushl %esi |
| cfi_adjust_cfa_offset (4) |
| pushl %ebp |
| cfi_adjust_cfa_offset (4) |
| cfi_rel_offset (ebp, 0) |
| pushl %ebx |
| cfi_adjust_cfa_offset (4) |
| |
| movl RES(%esp),%edi |
| cfi_rel_offset (edi, 12) |
| movl S(%esp),%esi |
| cfi_rel_offset (esi, 8) |
| movl SIZE(%esp),%ebx |
| cfi_rel_offset (ebx, 0) |
| movl CNT(%esp),%ecx |
| |
| /* We can use faster code for shift-by-1 under certain conditions. */ |
| cmp $1,%ecx |
| jne L(normal) |
| leal 4(%edi),%eax |
| cmpl %esi,%eax |
| jnc L(special) /* jump if res_ptr + 1 >= s_ptr */ |
| leal (%edi,%ebx,4),%eax |
| cmpl %eax,%esi |
| jnc L(special) /* jump if s_ptr >= res_ptr + size */ |
| |
| L(normal): |
| movl (%esi),%edx |
| addl $4,%esi |
| xorl %eax,%eax |
| shrdl %cl,%edx,%eax /* compute carry limb */ |
| pushl %eax /* push carry limb onto stack */ |
| cfi_adjust_cfa_offset (4) |
| |
| decl %ebx |
| pushl %ebx |
| cfi_adjust_cfa_offset (4) |
| shrl $3,%ebx |
| jz L(end) |
| |
| movl (%edi),%eax /* fetch destination cache line */ |
| |
| ALIGN (2) |
| L(oop): movl 28(%edi),%eax /* fetch destination cache line */ |
| movl %edx,%ebp |
| |
| movl (%esi),%eax |
| movl 4(%esi),%edx |
| shrdl %cl,%eax,%ebp |
| shrdl %cl,%edx,%eax |
| movl %ebp,(%edi) |
| movl %eax,4(%edi) |
| |
| movl 8(%esi),%ebp |
| movl 12(%esi),%eax |
| shrdl %cl,%ebp,%edx |
| shrdl %cl,%eax,%ebp |
| movl %edx,8(%edi) |
| movl %ebp,12(%edi) |
| |
| movl 16(%esi),%edx |
| movl 20(%esi),%ebp |
| shrdl %cl,%edx,%eax |
| shrdl %cl,%ebp,%edx |
| movl %eax,16(%edi) |
| movl %edx,20(%edi) |
| |
| movl 24(%esi),%eax |
| movl 28(%esi),%edx |
| shrdl %cl,%eax,%ebp |
| shrdl %cl,%edx,%eax |
| movl %ebp,24(%edi) |
| movl %eax,28(%edi) |
| |
| addl $32,%esi |
| addl $32,%edi |
| decl %ebx |
| jnz L(oop) |
| |
| L(end): popl %ebx |
| cfi_adjust_cfa_offset (-4) |
| andl $7,%ebx |
| jz L(end2) |
| L(oop2): |
| movl (%esi),%eax |
| shrdl %cl,%eax,%edx /* compute result limb */ |
| movl %edx,(%edi) |
| movl %eax,%edx |
| addl $4,%esi |
| addl $4,%edi |
| decl %ebx |
| jnz L(oop2) |
| |
| L(end2): |
| shrl %cl,%edx /* compute most significant limb */ |
| movl %edx,(%edi) /* store it */ |
| |
| popl %eax /* pop carry limb */ |
| cfi_adjust_cfa_offset (-4) |
| |
| popl %ebx |
| cfi_adjust_cfa_offset (-4) |
| cfi_restore (ebx) |
| popl %ebp |
| cfi_adjust_cfa_offset (-4) |
| cfi_restore (ebp) |
| popl %esi |
| cfi_adjust_cfa_offset (-4) |
| cfi_restore (esi) |
| popl %edi |
| cfi_adjust_cfa_offset (-4) |
| cfi_restore (edi) |
| |
| ret |
| |
| /* We loop from least 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_adjust_cfa_offset (16) |
| cfi_rel_offset (edi, 12) |
| cfi_rel_offset (esi, 8) |
| cfi_rel_offset (ebp, 4) |
| cfi_rel_offset (ebx, 0) |
| L(special): |
| leal -4(%edi,%ebx,4),%edi |
| leal -4(%esi,%ebx,4),%esi |
| |
| movl (%esi),%edx |
| subl $4,%esi |
| |
| decl %ebx |
| pushl %ebx |
| cfi_adjust_cfa_offset (4) |
| shrl $3,%ebx |
| |
| shrl $1,%edx |
| incl %ebx |
| decl %ebx |
| jz L(Lend) |
| |
| movl (%edi),%eax /* fetch destination cache line */ |
| |
| ALIGN (2) |
| L(Loop): |
| movl -28(%edi),%eax /* fetch destination cache line */ |
| movl %edx,%ebp |
| |
| movl (%esi),%eax |
| movl -4(%esi),%edx |
| rcrl $1,%eax |
| movl %ebp,(%edi) |
| rcrl $1,%edx |
| movl %eax,-4(%edi) |
| |
| movl -8(%esi),%ebp |
| movl -12(%esi),%eax |
| rcrl $1,%ebp |
| movl %edx,-8(%edi) |
| rcrl $1,%eax |
| movl %ebp,-12(%edi) |
| |
| movl -16(%esi),%edx |
| movl -20(%esi),%ebp |
| rcrl $1,%edx |
| movl %eax,-16(%edi) |
| rcrl $1,%ebp |
| movl %edx,-20(%edi) |
| |
| movl -24(%esi),%eax |
| movl -28(%esi),%edx |
| rcrl $1,%eax |
| movl %ebp,-24(%edi) |
| rcrl $1,%edx |
| movl %eax,-28(%edi) |
| |
| leal -32(%esi),%esi /* use leal not to clobber carry */ |
| leal -32(%edi),%edi |
| decl %ebx |
| jnz L(Loop) |
| |
| L(Lend): |
| popl %ebx |
| cfi_adjust_cfa_offset (-4) |
| sbbl %eax,%eax /* save carry in %eax */ |
| andl $7,%ebx |
| jz L(Lend2) |
| addl %eax,%eax /* restore carry from eax */ |
| L(Loop2): |
| movl %edx,%ebp |
| movl (%esi),%edx |
| rcrl $1,%edx |
| movl %ebp,(%edi) |
| |
| leal -4(%esi),%esi /* use leal not to clobber carry */ |
| leal -4(%edi),%edi |
| decl %ebx |
| jnz L(Loop2) |
| |
| jmp L(L1) |
| L(Lend2): |
| addl %eax,%eax /* restore carry from eax */ |
| L(L1): movl %edx,(%edi) /* store last limb */ |
| |
| movl $0,%eax |
| rcrl $1,%eax |
| |
| popl %ebx |
| cfi_adjust_cfa_offset (-4) |
| cfi_restore (ebx) |
| popl %ebp |
| cfi_adjust_cfa_offset (-4) |
| cfi_restore (ebp) |
| popl %esi |
| cfi_adjust_cfa_offset (-4) |
| cfi_restore (esi) |
| popl %edi |
| cfi_adjust_cfa_offset (-4) |
| cfi_restore (edi) |
| |
| ret |
| END (__mpn_rshift) |