dnl x86-64 mpn_divrem_2 -- Divide an mpn number by a normalized 2-limb number.
dnl Copyright 2007, 2008, 2010, 2014 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 best
C AMD K8,K9 18
C AMD K10 18
C AMD bull
C AMD pile
C AMD bobcat
C AMD jaguar
C Intel P4 68
C Intel core 34
C Intel NHM 30.25
C Intel SBR 21.3
C Intel IBR 21.4
C Intel HWL 20.6
C Intel BWL
C Intel atom 73
C VIA nano 33
C INPUT PARAMETERS
define(`qp', `%rdi')
define(`fn', `%rsi')
define(`up_param', `%rdx')
define(`un_param', `%rcx')
define(`dp', `%r8')
ABI_SUPPORT(DOS64)
ABI_SUPPORT(STD64)
ASM_START()
TEXT
ALIGN(16)
PROLOGUE(mpn_divrem_2)
FUNC_ENTRY(4)
IFDOS(` mov 56(%rsp), %r8 ')
push %r15
push %r14
push %r13
push %r12
lea -24(%rdx,%rcx,8), %r12 C r12 = &up[un-1]
mov %rsi, %r13
push %rbp
mov %rdi, %rbp
push %rbx
mov 8(%r8), %r11 C d1
mov 16(%r12), %rbx
mov (%r8), %r8 C d0
mov 8(%r12), %r10
xor R32(%r15), R32(%r15)
cmp %rbx, %r11
ja L(2)
setb %dl
cmp %r10, %r8
setbe %al
orb %al, %dl C "orb" form to placate Sun tools
je L(2)
inc R32(%r15)
sub %r8, %r10
sbb %r11, %rbx
L(2):
lea -3(%rcx,%r13), %r14 C un + fn - 3
test %r14, %r14
js L(end)
push %r8
push %r10
push %r11
IFSTD(` mov %r11, %rdi ')
IFDOS(` mov %r11, %rcx ')
IFDOS(` sub $32, %rsp ')
ASSERT(nz, `test $15, %rsp')
CALL( mpn_invert_limb)
IFDOS(` add $32, %rsp ')
pop %r11
pop %r10
pop %r8
mov %r11, %rdx
mov %rax, %rdi
imul %rax, %rdx
mov %rdx, %r9
mul %r8
xor R32(%rcx), R32(%rcx)
add %r8, %r9
adc $-1, %rcx
add %rdx, %r9
adc $0, %rcx
js 2f
1: dec %rdi
sub %r11, %r9
sbb $0, %rcx
jns 1b
2:
lea (%rbp,%r14,8), %rbp
mov %r11, %rsi
neg %rsi C -d1
C rax rbx rcx rdx rsi rdi rbp r8 r9 r10 r11 r12 r13 r14 r15
C n2 un -d1 dinv qp d0 q0 d1 up fn msl
ALIGN(16)
L(top): mov %rdi, %rax C di ncp
mul %rbx C 0, 17
mov %r10, %rcx C
add %rax, %rcx C 4
adc %rbx, %rdx C 5
mov %rdx, %r9 C q 6
imul %rsi, %rdx C 6
mov %r8, %rax C ncp
lea (%rdx, %r10), %rbx C n1 -= ... 10
xor R32(%r10), R32(%r10) C
mul %r9 C 7
cmp %r14, %r13 C
jg L(19) C
mov (%r12), %r10 C
sub $8, %r12 C
L(19): sub %r8, %r10 C ncp
sbb %r11, %rbx C 11
sub %rax, %r10 C 11
sbb %rdx, %rbx C 12
xor R32(%rax), R32(%rax) C
xor R32(%rdx), R32(%rdx) C
cmp %rcx, %rbx C 13
cmovnc %r8, %rax C 14
cmovnc %r11, %rdx C 14
adc $0, %r9 C adjust q 14
nop
add %rax, %r10 C 15
adc %rdx, %rbx C 16
cmp %r11, %rbx C
jae L(fix) C
L(bck): mov %r9, (%rbp) C
sub $8, %rbp C
dec %r14
jns L(top)
L(end): mov %r10, 8(%r12)
mov %rbx, 16(%r12)
pop %rbx
pop %rbp
pop %r12
pop %r13
pop %r14
mov %r15, %rax
pop %r15
FUNC_EXIT()
ret
L(fix): seta %dl
cmp %r8, %r10
setae %al
orb %dl, %al C "orb" form to placate Sun tools
je L(bck)
inc %r9
sub %r8, %r10
sbb %r11, %rbx
jmp L(bck)
EPILOGUE()