diff options
Diffstat (limited to 'REORG.TODO/sysdeps/i386/i586/rshift.S')
| -rw-r--r-- | REORG.TODO/sysdeps/i386/i586/rshift.S | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/i386/i586/rshift.S b/REORG.TODO/sysdeps/i386/i586/rshift.S new file mode 100644 index 0000000000..24c76ee0bb --- /dev/null +++ b/REORG.TODO/sysdeps/i386/i586/rshift.S @@ -0,0 +1,255 @@ +/* Pentium optimized __mpn_rshift -- + Copyright (C) 1992-2017 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) |