divrem_2.asm
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上传日期:2022-08-06
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- dnl x86-64 mpn_divrem_2 -- Divide an mpn number by a normalized 2-limb number.
- dnl Copyright 2007, 2008 Free Software Foundation, Inc.
- dnl This file is part of the GNU MP Library.
- dnl The GNU MP Library is free software; you can redistribute it and/or modify
- dnl it under the terms of the GNU Lesser General Public License as published
- dnl by the Free Software Foundation; either version 3 of the License, or (at
- dnl your option) any later version.
- 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 Lesser General Public
- dnl License for more details.
- dnl You should have received a copy of the GNU Lesser General Public License
- dnl along with the GNU MP Library. If not, see http://www.gnu.org/licenses/.
- include(`../config.m4')
- C norm frac
- C K8 20 20
- C P4 73 73
- C P6 core2 37 37
- C P6 corei7 33 33
- C TODO
- C * Perhaps compute the inverse without relying on divq? Could either use
- C Newton's method and mulq, or perhaps the faster fdiv.
- C * The loop has not been carefully tuned, nor analysed for critical path
- C length. It seems that 20 c/l is a bit long, compared to the 13 c/l for
- C mpn_divrem_1.
- C * Clean up. This code is really crude.
- C INPUT PARAMETERS
- define(`qp', `%rdi')
- define(`fn', `%rsi')
- define(`up_param', `%rdx')
- define(`un_param', `%rcx')
- define(`dp', `%r8')
- define(`dinv', `%r9')
- C rax rbx rcx rdx rsi rdi rbp r8 r9 r10 r11 r12 r13 r14 r15
- C cnt qp d dinv
- ASM_START()
- TEXT
- ALIGN(16)
- PROLOGUE(mpn_divrem_2)
- push %r15
- lea (%rdx,%rcx,8), %rax
- push %r14
- push %r13
- mov %rsi, %r13
- push %r12
- lea -24(%rax), %r12
- push %rbp
- mov %rdi, %rbp
- push %rbx
- mov 8(%r8), %r11
- mov -8(%rax), %r9
- mov (%r8), %r8
- mov -16(%rax), %r10
- xor R32(%r15), R32(%r15)
- cmp %r9, %r11
- ja L(2)
- setb %dl
- cmp %r10, %r8
- setbe %al
- or %al, %dl
- jne L(23)
- L(2):
- lea -3(%rcx,%r13), %rbx C un + fn - 3
- test %rbx, %rbx
- js L(6)
- mov %r11, %rdx
- mov $-1, %rax
- not %rdx
- div %r11
- mov %r11, %rdx
- mov %rax, %rdi
- imul %rax, %rdx
- mov %rdx, %r14
- mul %r8
- mov %rdx, %rcx
- mov $-1, %rdx
- add %r8, %r14
- adc $0, %rdx
- add %rcx, %r14
- adc $0, %rdx
- js L(8)
- L(18):
- dec %rdi
- sub %r11, %r14
- sbb $0, %rdx
- jns L(18)
- L(8):
- C rax rbx rcx rdx rsi rdi rbp r8 r9 r10 r11 r12 r13 r14 r15
- C n2 un n1 dinv qp d0 d1 up fn msl
- C n2 un -d1 n1 dinv XX XX
- ifdef(`NEW',`
- lea (%rbp,%rbx,8), %rbp
- mov %rbx, %rcx C un
- mov %r9, %rbx
- mov %rdi, %r9 C di
- mov %r10, %r14
- mov %r11, %rsi
- neg %rsi C -d1
- ALIGN(16)
- L(loop):
- mov %r9, %rax C di ncp
- mul %rbx C 0, 18
- add %r14, %rax C 4
- mov %rax, %r10 C q0 5
- adc %rbx, %rdx C 5
- mov %rdx, %rdi C q 6
- imul %rsi, %rdx C 6
- mov %r8, %rax C ncp
- lea (%rdx, %r14), %rbx C n1 -= ... 7
- mul %rdi C 7
- xor R32(%r14), R32(%r14) C
- cmp %rcx, %r13 C
- jg L(19) C
- mov (%r12), %r14 C
- sub $8, %r12 C
- L(19): sub %r8, %r14 C ncp
- sbb %r11, %rbx C 9
- sub %rax, %r14 C 11
- sbb %rdx, %rbx C 12
- inc %rdi C 7
- xor R32(%rdx), R32(%rdx) C
- cmp %r10, %rbx C 13
- mov %r8, %rax C d0 ncp
- adc $-1, %rdx C mask 14
- add %rdx, %rdi C q-- 15
- and %rdx, %rax C d0 or 0 15
- and %r11, %rdx C d1 or 0 15
- add %rax, %r14 C 16
- adc %rdx, %rbx C 16
- cmp %r11, %rbx C 17
- jae L(fix) C
- L(bck): mov %rdi, (%rbp) C
- sub $8, %rbp C
- dec %rcx
- jns L(loop)
- mov %r14, %r10
- mov %rbx, %r9
- ',`
- lea (%rbp,%rbx,8), %rbp
- mov %rbx, %rcx
- mov %r9, %rax
- mov %r10, %rsi
- ALIGN(16)
- L(loop):
- mov %rax, %r14 C 0, 19
- mul %rdi C 0
- mov %r11, %r9 C 1
- add %rsi, %rax C 4
- mov %rax, %rbx C q0 5
- adc %r14, %rdx C q 5
- lea 1(%rdx), %r10 C 6
- mov %rdx, %rax C 6
- imul %rdx, %r9 C 6
- sub %r9, %rsi C 10
- xor R32(%r9), R32(%r9) C
- mul %r8 C 7
- cmp %rcx, %r13 C
- jg L(13) C
- mov (%r12), %r9 C
- sub $8, %r12 C
- L(13): sub %r8, %r9 C ncp
- sbb %r11, %rsi C 11
- sub %rax, %r9 C 11
- sbb %rdx, %rsi C 12
- cmp %rbx, %rsi C 13
- sbb %rax, %rax C 14
- not %rax C 15
- add %rax, %r10 C 16
- mov %r8, %rbx C ncp
- and %rax, %rbx C 16
- and %r11, %rax C 16
- add %rbx, %r9 C 17
- adc %rsi, %rax C 18
- cmp %rax, %r11 C 19
- jbe L(fix) C
- L(bck): mov %r10, (%rbp) C
- sub $8, %rbp C
- mov %r9, %rsi C 18
- dec %rcx
- jns L(loop)
- mov %rsi, %r10
- mov %rax, %r9
- ')
- L(6):
- mov %r10, 8(%r12)
- mov %r9, 16(%r12)
- pop %rbx
- pop %rbp
- pop %r12
- pop %r13
- pop %r14
- mov %r15, %rax
- pop %r15
- ret
- L(23): inc R32(%r15)
- sub %r8, %r10
- sbb %r11, %r9
- jmp L(2)
- ifdef(`NEW',`
- L(fix): seta %dl
- cmp %r8, %r14
- setae %al
- orb %dl, %al
- je L(bck)
- inc %rdi
- sub %r8, %r14
- sbb %r11, %rbx
- jmp L(bck)
- ',`
- L(fix): jb L(88)
- cmp %r8, %r9
- jb L(bck)
- L(88): inc %r10
- sub %r8, %r9
- sbb %r11, %rax
- jmp L(bck)
- ')
- EPILOGUE()