dnl x86-32 mpn_mod_1_1p, requiring cmov.
dnl Contributed to the GNU project by Niels Möller and Torbjorn Granlund.
dnl Copyright 2010, 2011 Free Software Foundation, Inc.
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 modify
dnl it under the terms of either:
dnl
dnl * the GNU Lesser General Public License as published by the Free
dnl Software Foundation; either version 3 of the License, or (at your
dnl option) any later version.
dnl
dnl or
dnl
dnl * the GNU General Public License as published by the Free Software
dnl Foundation; either version 2 of the License, or (at your option) any
dnl later version.
dnl
dnl or both in parallel, as here.
dnl
dnl The GNU MP Library is distributed in the hope that it will be useful, but
dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
dnl for more details.
dnl
dnl You should have received copies of the GNU General Public License and the
dnl GNU Lesser General Public License along with the GNU MP Library. If not,
dnl see https://www.gnu.org/licenses/.
include(`../config.m4')
C cycles/limb
C P5 ?
C P6 model 0-8,10-12 ?
C P6 model 9 (Banias) ?
C P6 model 13 (Dothan) ?
C P4 model 0 (Willamette) ?
C P4 model 1 (?) ?
C P4 model 2 (Northwood) ?
C P4 model 3 (Prescott) ?
C P4 model 4 (Nocona) ?
C AMD K6 ?
C AMD K7 7
C AMD K8 ?
define(`B2mb', `%ebx')
define(`r0', `%esi')
define(`r2', `%ebp')
define(`t0', `%edi')
define(`ap', `%ecx') C Also shift count
C Stack frame
C pre 36(%esp)
C b 32(%esp)
C n 28(%esp)
C ap 24(%esp)
C return 20(%esp)
C %ebp 16(%esp)
C %edi 12(%esp)
C %esi 8(%esp)
C %ebx 4(%esp)
C B2mod (%esp)
define(`B2modb', `(%esp)')
define(`n', `28(%esp)')
define(`b', `32(%esp)')
define(`pre', `36(%esp)')
C mp_limb_t
C mpn_mod_1_1p (mp_srcptr ap, mp_size_t n, mp_limb_t b, mp_limb_t pre[4])
C
C The pre array contains bi, cnt, B1modb, B2modb
C Note: This implementation needs B1modb only when cnt > 0
ASM_START()
TEXT
ALIGN(8)
PROLOGUE(mpn_mod_1_1p)
push %ebp
push %edi
push %esi
push %ebx
mov 32(%esp), %ebp C pre[]
mov 12(%ebp), %eax C B2modb
push %eax C Put it on stack
mov n, %edx
mov 24(%esp), ap
lea (ap, %edx, 4), ap
mov -4(ap), %eax
cmp $3, %edx
jnc L(first)
mov -8(ap), r0
jmp L(reduce_two)
L(first):
C First iteration, no r2
mull B2modb
mov -12(ap), r0
add %eax, r0
mov -8(ap), %eax
adc %edx, %eax
sbb r2, r2
subl $3, n
lea -16(ap), ap
jz L(reduce_three)
mov B2modb, B2mb
sub b, B2mb
lea (B2mb, r0), t0
jmp L(mid)
ALIGN(16)
L(top): C Loopmixed to 7 c/l on k7
add %eax, r0
lea (B2mb, r0), t0
mov r2, %eax
adc %edx, %eax
sbb r2, r2
L(mid): mull B2modb
and B2modb, r2
add r0, r2
decl n
mov (ap), r0
cmovc( t0, r2)
lea -4(ap), ap
jnz L(top)
add %eax, r0
mov r2, %eax
adc %edx, %eax
sbb r2, r2
L(reduce_three):
C Eliminate r2
and b, r2
sub r2, %eax
L(reduce_two):
mov pre, %ebp
movb 4(%ebp), %cl
test %cl, %cl
jz L(normalized)
C Unnormalized, use B1modb to reduce to size < B b
mull 8(%ebp)
xor t0, t0
add %eax, r0
adc %edx, t0
mov t0, %eax
C Left-shift to normalize
shld %cl, r0, %eax C Always use shld?
shl %cl, r0
jmp L(udiv)
L(normalized):
mov %eax, t0
sub b, t0
cmovnc( t0, %eax)
L(udiv):
lea 1(%eax), t0
mull (%ebp)
mov b, %ebx C Needed in register for lea
add r0, %eax
adc t0, %edx
imul %ebx, %edx
sub %edx, r0
cmp r0, %eax
lea (%ebx, r0), %eax
cmovnc( r0, %eax)
cmp %ebx, %eax
jnc L(fix)
L(ok): shr %cl, %eax
add $4, %esp
pop %ebx
pop %esi
pop %edi
pop %ebp
ret
L(fix): sub %ebx, %eax
jmp L(ok)
EPILOGUE()
PROLOGUE(mpn_mod_1_1p_cps)
push %ebp
mov 12(%esp), %ebp
push %esi
bsr %ebp, %ecx
push %ebx
xor $31, %ecx
mov 16(%esp), %esi
sal %cl, %ebp
mov %ebp, %edx
not %edx
mov $-1, %eax
div %ebp C On K7, invert_limb would be a few cycles faster.
mov %eax, (%esi) C store bi
mov %ecx, 4(%esi) C store cnt
neg %ebp
mov $1, %edx
shld %cl, %eax, %edx
imul %ebp, %edx
shr %cl, %edx
imul %ebp, %eax
mov %edx, 8(%esi) C store B1modb
mov %eax, 12(%esi) C store B2modb
pop %ebx
pop %esi
pop %ebp
ret
EPILOGUE()