+++ /dev/null
-dnl Intel Pentium mpn_lshift -- mpn left shift.
-dnl
-dnl cycles/limb
-dnl P5,P54: 6.0
-dnl P55: 5.375
-
-
-dnl Copyright (C) 1992, 1994, 1995, 1996, 1999, 2000 Free Software
-dnl Foundation, Inc.
-dnl
-dnl This file is part of the GNU MP Library.
-dnl
-dnl The GNU MP Library is free software; you can redistribute it and/or
-dnl modify it under the terms of the GNU Lesser General Public License as
-dnl published by the Free Software Foundation; either version 2.1 of the
-dnl License, or (at your option) any later version.
-dnl
-dnl The GNU MP Library is distributed in the hope that it will be useful,
-dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
-dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-dnl Lesser General Public License for more details.
-dnl
-dnl You should have received a copy of the GNU Lesser General Public
-dnl License along with the GNU MP Library; see the file COPYING.LIB. If
-dnl not, write to the Free Software Foundation, Inc., 59 Temple Place -
-dnl Suite 330, Boston, MA 02111-1307, USA.
-
-
-include(`../config.m4')
-
-
-C mp_limb_t mpn_lshift (mp_ptr dst, mp_srcptr src, mp_size_t size,
-C unsigned shift);
-C
-C The main shift-by-N loop should run at 5.375 c/l and that's what P55 does,
-C but P5 and P54 run only at 6.0 c/l, which is 4 cycles lost somewhere.
-
-defframe(PARAM_SHIFT,16)
-defframe(PARAM_SIZE, 12)
-defframe(PARAM_SRC, 8)
-defframe(PARAM_DST, 4)
-
- .text
- ALIGN(8)
-PROLOGUE(mpn_lshift)
-
- pushl %edi
- pushl %esi
- pushl %ebx
- pushl %ebp
-deflit(`FRAME',16)
-
- movl PARAM_DST,%edi
- movl PARAM_SRC,%esi
- movl PARAM_SIZE,%ebp
- movl PARAM_SHIFT,%ecx
-
-C We can use faster code for shift-by-1 under certain conditions.
- cmp $1,%ecx
- jne L(normal)
- leal 4(%esi),%eax
- cmpl %edi,%eax
- jnc L(special) C jump if s_ptr + 1 >= res_ptr
- leal (%esi,%ebp,4),%eax
- cmpl %eax,%edi
- jnc L(special) C jump if res_ptr >= s_ptr + size
-
-L(normal):
- 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) C compute carry limb
- pushl %eax C push carry limb onto stack
-
- decl %ebp
- pushl %ebp
- shrl $3,%ebp
- jz L(end)
-
- movl (%edi),%eax C fetch destination cache line
-
- ALIGN(4)
-L(oop): movl -28(%edi),%eax C 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 L(oop)
-
-L(end): popl %ebp
- andl $7,%ebp
- jz L(end2)
-L(oop2):
- movl (%esi),%eax
- shldl( %cl,%eax,%edx)
- movl %edx,(%edi)
- movl %eax,%edx
- subl $4,%esi
- subl $4,%edi
- decl %ebp
- jnz L(oop2)
-
-L(end2):
- shll %cl,%edx C compute least significant limb
- movl %edx,(%edi) C store it
-
- popl %eax C pop carry limb
-
- popl %ebp
- popl %ebx
- popl %esi
- popl %edi
- ret
-
-
-C We loop from least significant end of the arrays, which is only
-C permissable if the source and destination don't overlap, since the
-C function is documented to work for overlapping source and destination.
-
-L(special):
- movl (%esi),%edx
- addl $4,%esi
-
- decl %ebp
- pushl %ebp
- shrl $3,%ebp
-
- addl %edx,%edx
- incl %ebp
- decl %ebp
- jz L(Lend)
-
- movl (%edi),%eax C fetch destination cache line
-
- ALIGN(4)
-L(Loop):
- movl 28(%edi),%eax C 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 C use leal not to clobber carry
- leal 32(%edi),%edi
- decl %ebp
- jnz L(Loop)
-
-L(Lend):
- popl %ebp
- sbbl %eax,%eax C save carry in %eax
- andl $7,%ebp
- jz L(Lend2)
- addl %eax,%eax C restore carry from eax
-L(Loop2):
- movl %edx,%ebx
- movl (%esi),%edx
- adcl %edx,%edx
- movl %ebx,(%edi)
-
- leal 4(%esi),%esi C use leal not to clobber carry
- leal 4(%edi),%edi
- decl %ebp
- jnz L(Loop2)
-
- jmp L(L1)
-L(Lend2):
- addl %eax,%eax C restore carry from eax
-L(L1): movl %edx,(%edi) C store last limb
-
- sbbl %eax,%eax
- negl %eax
-
- popl %ebp
- popl %ebx
- popl %esi
- popl %edi
- ret
-
-EPILOGUE()
projects / ghc-hetmet.git / blobdiff