mpir/mpn/x86_64/sub_err2_n.asm
2014-02-07 13:05:55 +00:00

161 lines
4.1 KiB
NASM

dnl AMD64 mpn_sub_err2_n
dnl Copyright (C) 2009, David Harvey
dnl All rights reserved.
dnl Redistribution and use in source and binary forms, with or without
dnl modification, are permitted provided that the following conditions are
dnl met:
dnl 1. Redistributions of source code must retain the above copyright notice,
dnl this list of conditions and the following disclaimer.
dnl 2. Redistributions in binary form must reproduce the above copyright
dnl notice, this list of conditions and the following disclaimer in the
dnl documentation and/or other materials provided with the distribution.
dnl THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
dnl ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
dnl LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
dnl PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
dnl HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
dnl SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
dnl TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
dnl PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
dnl LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
dnl NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
dnl SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
include(`../config.m4')
C cycles/limb
C K8,K9: 4.5
C K10: ?
C P4: ?
C P6-15 (Core2): ?
C P6-28 (Atom): ?
C
C mp_limb_t mpn_sub_err2_n (* rp,* up, * vp, * ep, * yp1, * yp2, n, cy)
C
C INPUT PARAMETERS
define(`rp', `%rdi')
define(`up', `%rsi')
define(`vp', `%rdx')
define(`ep', `%rcx')
define(`yp1', `%r8')
define(`yp2', `%r9')
define(`n_param', `8(%rsp)')
define(`cy_param', `16(%rsp)')
define(`cy1', `%r14')
define(`cy2', `%rax')
define(`n', `%r10')
define(`w', `%rbx')
define(`e1l', `%rbp')
define(`e1h', `%r11')
define(`e2l', `%r12')
define(`e2h', `%r13')
ASM_START()
TEXT
ALIGN(16)
PROLOGUE(mpn_sub_err2_n)
mov cy_param, cy2 C cy2
mov n_param, n C n
push %rbx
push %rbp
push %r12
push %r13
push %r14
xor e1l, e1l C zero e1l, elh, e2l, e2h
xor e1h, e1h
xor e2l, e2l
xor e2h, e2h
sub yp1, yp2 C yp2 -= yp1
lea (rp,n,8), rp C rp += n, up += n, vp += n
lea (up,n,8), up
lea (vp,n,8), vp
test $1, n C if n is odd goto L(odd)
jnz L(odd)
lea -8(yp1,n,8), yp1 C { yp1 += n - 1 }
neg n C { n = -n }
jmp L(top)
ALIGN(16)
L(odd): C n is odd, do extra iteration
lea -16(yp1,n,8), yp1 C yp1 += n - 2
neg n C { n = -n }
shr $1, cy2 C rp[0] = up[0] - vp[0] - (cy2&1)
mov (up,n,8), w
sbb (vp,n,8), w
cmovc 8(yp1), e1l C if borrow2 el1 = *(yp1+1)
cmovc 8(yp1,yp2), e2l C if borrow2 e2l = *(yp2+1)
mov w, (rp,n,8)
sbb cy2, cy2 C move borrow2 into cy2
inc n C n++
jz L(end) C goto end if we are done
ALIGN(16)
L(top):
mov (up,n,8), w
shr $1, cy2 C restore borrow2
sbb (vp,n,8), w
mov w, (rp,n,8) C rp[n] = up[n] - vp[n] - borrow2
sbb cy1, cy1 C generate mask, preserve CF
mov 8(up,n,8), w C rp[n] = up[n+1] - vp[n+1] - borrow1
sbb 8(vp,n,8), w
mov w, 8(rp,n,8)
sbb cy2, cy2 C generate mask, preserve CF
mov (yp1), w C (e1h:e1l) += cy1 * yp1 limb
and cy1, w
add w, e1l
adc $0, e1h
and (yp1,yp2), cy1 C (e2h:e2l) += cy1 * yp2 limb
add cy1, e2l
adc $0, e2h
mov -8(yp1), w C (e1h:e1l) += cy2 * next yp1 limb
and cy2, w
add w, e1l
adc $0, e1h
mov -8(yp1,yp2), w C (e2h:e2l) += cy2 * next yp2 limb
and cy2, w
add w, e2l
adc $0, e2h
add $2, n C n += 2
lea -16(yp1), yp1 C yp1 -= 2
jnz L(top) C if not done goto top
L(end):
mov e1l, (ep) C write out e1l, e1h, e2l, e2h
mov e1h, 8(ep)
mov e2l, 16(ep)
mov e2h, 24(ep)
and $1, %eax C return carry
pop %r14
pop %r13
pop %r12
pop %rbp
pop %rbx
ret
EPILOGUE()