dnl AMD64 mpn_bdiv_q_1, mpn_pi1_bdiv_q_1 -- Hensel division by 1-limb divisor.
dnl Copyright 2001, 2002, 2004-2006, 2010-2012, 2017 Free Software Foundation,
dnl 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 cycles/limb
C norm unorm
C AMD K8,K9 11 11
C AMD K10 11 11
C AMD bull 13.5 14
C AMD pile 14 15
C AMD steam
C AMD excavator
C AMD bobcat 14 14
C AMD jaguar 14.5 15
C Intel P4 33 33
C Intel core2 13.5 13.25
C Intel NHM 14 14
C Intel SBR 8 8.25
C Intel IBR 7.75 7.85
C Intel HWL 8 8
C Intel BWL 8 8
C Intel SKL 8 8
C Intel atom 34 36
C Intel SLM 13.7 13.5
C VIA nano 19.25 19.25 needs re-measuring
C INPUT PARAMETERS
define(`rp', `%rdi')
define(`up', `%rsi')
define(`n', `%rdx')
define(`d', `%rcx')
define(`di', `%r8') C just mpn_pi1_bdiv_q_1
define(`ncnt', `%r9') C just mpn_pi1_bdiv_q_1
ABI_SUPPORT(DOS64)
ABI_SUPPORT(STD64)
ASM_START()
TEXT
ALIGN(16)
PROLOGUE(mpn_bdiv_q_1)
FUNC_ENTRY(4)
push %rbx
mov %rcx, %rax
xor R32(%rcx), R32(%rcx) C ncnt count
mov %rdx, %r10
bt $0, R32(%rax)
jnc L(evn) C skip bsf unless divisor is even
L(odd): mov %rax, %rbx
shr R32(%rax)
and $127, R32(%rax) C d/2, 7 bits
LEA( binvert_limb_table, %rdx)
movzbl (%rdx,%rax), R32(%rax) C inv 8 bits
mov %rbx, %r11 C d without twos
lea (%rax,%rax), R32(%rdx) C 2*inv
imul R32(%rax), R32(%rax) C inv*inv
imul R32(%rbx), R32(%rax) C inv*inv*d
sub R32(%rax), R32(%rdx) C inv = 2*inv - inv*inv*d, 16 bits
lea (%rdx,%rdx), R32(%rax) C 2*inv
imul R32(%rdx), R32(%rdx) C inv*inv
imul R32(%rbx), R32(%rdx) C inv*inv*d
sub R32(%rdx), R32(%rax) C inv = 2*inv - inv*inv*d, 32 bits
lea (%rax,%rax), %r8 C 2*inv
imul %rax, %rax C inv*inv
imul %rbx, %rax C inv*inv*d
sub %rax, %r8 C inv = 2*inv - inv*inv*d, 64 bits
jmp L(pi1)
L(evn): bsf %rax, %rcx
shr R8(%rcx), %rax
jmp L(odd)
EPILOGUE()
PROLOGUE(mpn_pi1_bdiv_q_1)
FUNC_ENTRY(4)
IFDOS(` mov 56(%rsp), %r8 ')
IFDOS(` mov 64(%rsp), %r9 ')
push %rbx
mov %rcx, %r11 C d
mov %rdx, %r10 C n
mov %r9, %rcx C ncnt
L(pi1): mov (up), %rax C up[0]
dec %r10
jz L(one)
lea 8(up,%r10,8), up C up end
lea (rp,%r10,8), rp C rp end
neg %r10 C -n
test R32(%rcx), R32(%rcx)
jnz L(unorm) C branch if count != 0
xor R32(%rbx), R32(%rbx)
jmp L(nent)
ALIGN(8)
L(ntop):mul %r11 C carry limb in rdx 0 10
mov -8(up,%r10,8), %rax C
sub %rbx, %rax C apply carry bit
setc R8(%rbx) C
sub %rdx, %rax C apply carry limb 5
adc $0, R32(%rbx) C 6
L(nent):imul %r8, %rax C 6
mov %rax, (rp,%r10,8) C
inc %r10 C
jnz L(ntop)
mov -8(up), %r9 C up high limb
jmp L(com)
L(unorm):
mov (up,%r10,8), %r9 C up[1]
shr R8(%rcx), %rax C
neg R32(%rcx)
shl R8(%rcx), %r9 C
neg R32(%rcx)
or %r9, %rax
xor R32(%rbx), R32(%rbx)
jmp L(uent)
ALIGN(8)
L(utop):mul %r11 C carry limb in rdx 0 10
mov (up,%r10,8), %rax C
shl R8(%rcx), %rax C
neg R32(%rcx)
or %r9, %rax
sub %rbx, %rax C apply carry bit
setc R8(%rbx) C
sub %rdx, %rax C apply carry limb 5
adc $0, R32(%rbx) C 6
L(uent):imul %r8, %rax C 6
mov (up,%r10,8), %r9 C
shr R8(%rcx), %r9 C
neg R32(%rcx)
mov %rax, (rp,%r10,8) C
inc %r10 C
jnz L(utop)
L(com): mul %r11 C carry limb in rdx
sub %rbx, %r9 C apply carry bit
sub %rdx, %r9 C apply carry limb
imul %r8, %r9
mov %r9, (rp)
pop %rbx
FUNC_EXIT()
ret
L(one): shr R8(%rcx), %rax
imul %r8, %rax
mov %rax, (rp)
pop %rbx
FUNC_EXIT()
ret
EPILOGUE()