mpir/mpn/x86/mul_basecase.asm

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dnl x86 mpn_mul_basecase -- Multiply two limb vectors and store the result
dnl in a third limb vector.
dnl Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002 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., 51 Franklin Street,
dnl Fifth Floor, Boston, MA 02110-1301, USA.
include(`../config.m4')
C cycles/crossproduct
C P5: 15
C P6: 7.5
C K6: 12.5
C K7: 5.5
C P4: 24
C void mpn_mul_basecase (mp_ptr wp,
C mp_srcptr xp, mp_size_t xsize,
C mp_srcptr yp, mp_size_t ysize);
C
C This was written in a haste since the Pentium optimized code that was used
C for all x86 machines was slow for the Pentium II. This code would benefit
C from some cleanup.
C
C To shave off some percentage of the run-time, one should make 4 variants
C of the Louter loop, for the four different outcomes of un mod 4. That
C would avoid Loop0 altogether. Code expansion would be > 4-fold for that
C part of the function, but since it is not very large, that would be
C acceptable.
C
C The mul loop (at L(oopM)) might need some tweaking. It's current speed is
C unknown.
defframe(PARAM_YSIZE,20)
defframe(PARAM_YP, 16)
defframe(PARAM_XSIZE,12)
defframe(PARAM_XP, 8)
defframe(PARAM_WP, 4)
defframe(VAR_MULTIPLIER, -4)
defframe(VAR_COUNTER, -8)
deflit(VAR_STACK_SPACE, 8)
TEXT
ALIGN(8)
PROLOGUE(mpn_mul_basecase)
deflit(`FRAME',0)
subl $VAR_STACK_SPACE,%esp
pushl %esi
pushl %ebp
pushl %edi
deflit(`FRAME',eval(VAR_STACK_SPACE+12))
movl PARAM_XP,%esi
movl PARAM_WP,%edi
movl PARAM_YP,%ebp
movl (%esi),%eax C load xp[0]
mull (%ebp) C multiply by yp[0]
movl %eax,(%edi) C store to wp[0]
movl PARAM_XSIZE,%ecx C xsize
decl %ecx C If xsize = 1, ysize = 1 too
jz L(done)
pushl %ebx
FRAME_pushl()
movl %edx,%ebx
leal 4(%esi),%esi
leal 4(%edi),%edi
L(oopM):
movl (%esi),%eax C load next limb at xp[j]
leal 4(%esi),%esi
mull (%ebp)
addl %ebx,%eax
movl %edx,%ebx
adcl $0,%ebx
movl %eax,(%edi)
leal 4(%edi),%edi
decl %ecx
jnz L(oopM)
movl %ebx,(%edi) C most significant limb of product
addl $4,%edi C increment wp
movl PARAM_XSIZE,%eax
shll $2,%eax
subl %eax,%edi
subl %eax,%esi
movl PARAM_YSIZE,%eax C ysize
decl %eax
jz L(skip)
movl %eax,VAR_COUNTER C set index i to ysize
L(outer):
movl PARAM_YP,%ebp C yp
addl $4,%ebp C make ebp point to next v limb
movl %ebp,PARAM_YP
movl (%ebp),%eax C copy y limb ...
movl %eax,VAR_MULTIPLIER C ... to stack slot
movl PARAM_XSIZE,%ecx
xorl %ebx,%ebx
andl $3,%ecx
jz L(end0)
L(oop0):
movl (%esi),%eax
mull VAR_MULTIPLIER
leal 4(%esi),%esi
addl %ebx,%eax
movl $0,%ebx
adcl %ebx,%edx
addl %eax,(%edi)
adcl %edx,%ebx C propagate carry into cylimb
leal 4(%edi),%edi
decl %ecx
jnz L(oop0)
L(end0):
movl PARAM_XSIZE,%ecx
shrl $2,%ecx
jz L(endX)
ALIGN(8)
L(oopX):
movl (%esi),%eax
mull VAR_MULTIPLIER
addl %eax,%ebx
movl $0,%ebp
adcl %edx,%ebp
movl 4(%esi),%eax
mull VAR_MULTIPLIER
addl %ebx,(%edi)
adcl %eax,%ebp C new lo + cylimb
movl $0,%ebx
adcl %edx,%ebx
movl 8(%esi),%eax
mull VAR_MULTIPLIER
addl %ebp,4(%edi)
adcl %eax,%ebx C new lo + cylimb
movl $0,%ebp
adcl %edx,%ebp
movl 12(%esi),%eax
mull VAR_MULTIPLIER
addl %ebx,8(%edi)
adcl %eax,%ebp C new lo + cylimb
movl $0,%ebx
adcl %edx,%ebx
addl %ebp,12(%edi)
adcl $0,%ebx C propagate carry into cylimb
leal 16(%esi),%esi
leal 16(%edi),%edi
decl %ecx
jnz L(oopX)
L(endX):
movl %ebx,(%edi)
addl $4,%edi
C we incremented wp and xp in the loop above; compensate
movl PARAM_XSIZE,%eax
shll $2,%eax
subl %eax,%edi
subl %eax,%esi
movl VAR_COUNTER,%eax
decl %eax
movl %eax,VAR_COUNTER
jnz L(outer)
L(skip):
popl %ebx
popl %edi
popl %ebp
popl %esi
addl $8,%esp
ret
L(done):
movl %edx,4(%edi) C store to wp[1]
popl %edi
popl %ebp
popl %esi
addl $8,%esp
ret
EPILOGUE()