--- /dev/null
+dnl x86-64 mpn_divrem_1 -- mpn by limb division.
+
+dnl Copyright 2004, 2005, 2007, 2008, 2009 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 unorm frac
+C K8 13 13 12
+C P4 44.2 44.2 42.3
+C P6-15 (Core2) 24.5 24.5 19.3
+C P6-15 (Atom) 42 52 37
+
+C TODO
+C * Compute the inverse without relying on the div instruction.
+C Newton's method and mulq, or perhaps the faster fdiv.
+C * Tune prologue.
+C * Optimize for Core 2.
+
+C The code for unnormalized divisors works also for normalized divisors, but
+C for some reason it runs really slowly (on K8) for that case. Use special
+C code until we can address this. The Intel Atom is also affected, but
+C understandably (shld slowness).
+define(`SPECIAL_CODE_FOR_NORMALIZED_DIVISOR',1)
+
+C mp_limb_t
+C mpn_divrem_1 (mp_ptr qp, mp_size_t fn,
+C mp_srcptr np, mp_size_t nn, mp_limb_t d)
+
+C mp_limb_t
+C mpn_preinv_divrem_1 (mp_ptr qp, mp_size_t fn,
+C mp_srcptr np, mp_size_t nn, mp_limb_t d,
+C mp_limb_t dinv, int cnt)
+
+C INPUT PARAMETERS
+define(`qp', `%rdi')
+define(`fn_param', `%rsi')
+define(`up_param', `%rdx')
+define(`un_param', `%rcx')
+define(`d', `%r8')
+define(`dinv', `%r9') C only for mpn_preinv_divrem_1
+C shift passed on stack C only for mpn_preinv_divrem_1
+
+define(`cnt', `%rcx')
+define(`up', `%rsi')
+define(`fn', `%r12')
+define(`un', `%rbx')
+
+
+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_preinv_divrem_1)
+ xor %eax, %eax
+ push %r13
+ push %r12
+ push %rbp
+ push %rbx
+
+ mov fn_param, fn
+ mov un_param, un
+ add fn_param, un_param
+ mov up_param, up
+
+ lea -8(qp,un_param,8), qp
+
+ test d, d
+ js L(nent)
+ mov 40(%rsp), R8(cnt)
+ shl R8(cnt), d
+ jmp L(uent)
+EPILOGUE()
+
+ ALIGN(16)
+PROLOGUE(mpn_divrem_1)
+ xor %eax, %eax
+ push %r13
+ push %r12
+ push %rbp
+ push %rbx
+
+ mov fn_param, fn
+ mov un_param, un
+ add fn_param, un_param
+ mov up_param, up
+ je L(ret)
+
+ lea -8(qp,un_param,8), qp
+ xor R32(%rbp), R32(%rbp)
+
+
+ifdef(`SPECIAL_CODE_FOR_NORMALIZED_DIVISOR',`
+ test d, d
+ jns L(unnormalized)
+
+L(normalized):
+ test un, un
+ je L(8) C un == 0
+ mov -8(up,un,8), %rbp
+ dec un
+ mov %rbp, %rax
+ sub d, %rbp
+ cmovb %rax, %rbp
+ sbb %eax, %eax
+ inc %eax
+ mov %rax, (qp)
+ lea -8(qp), qp
+L(8):
+ mov d, %rdx
+ mov $-1, %rax
+ not %rdx
+ div d C FREE rax rdx rcx r9 r10 r11
+ mov %rax, dinv
+ mov %rbp, %rax
+ jmp L(nent)
+
+ ALIGN(16)
+L(nloop): C cycK8 cycP6 cycP4
+ mov (up,un,8), %r10 C
+ lea 1(%rax), %rbp C
+ mul dinv C 0,13 0,19 0,45
+ add %r10, %rax C 4 8 12
+ adc %rbp, %rdx C 5 9 13
+ mov %rax, %rbp C 5 9 13
+ mov %rdx, %r13 C 6 11 23
+ imul d, %rdx C 6 11 23
+ sub %rdx, %r10 C 10 16 33
+ mov d, %rax C
+ add %r10, %rax C 11 17 34
+ cmp %rbp, %r10 C 11 17 34
+ cmovb %r10, %rax C 12 18 35
+ adc $-1, %r13 C
+ cmp d, %rax C
+ jae L(nfx) C
+L(nok): mov %r13, (qp) C
+ sub $8, qp C
+L(nent):dec un C
+ jns L(nloop) C
+
+ xor %ecx, %ecx
+ jmp L(87)
+
+L(nfx): sub d, %rax
+ inc %r13
+ jmp L(nok)
+')
+
+L(unnormalized):
+ test un, un
+ je L(44)
+ mov -8(up,un,8), %rax
+ cmp d, %rax
+ jae L(44)
+ mov %rbp, (qp)
+ mov %rax, %rbp
+ lea -8(qp), qp
+ je L(ret)
+ dec un
+L(44):
+ bsr d, %rcx
+ not %ecx
+ sal %cl, d
+ sal %cl, %rbp
+ mov d, %rdx
+ mov $-1, %rax
+ not %rdx
+ div d C FREE rax rdx r9 r10 r11
+ test un, un
+ mov %rax, dinv
+ mov %rbp, %rax
+ je L(87)
+L(uent):
+ mov -8(up,un,8), %rbp
+ shr %cl, %rax
+ shld %cl, %rbp, %rax
+ sub $2, un
+ js L(ulast)
+
+ ALIGN(16)
+L(uloop):
+ nop
+ mov (up,un,8), %r10
+ lea 1(%rax), %r11
+ shld %cl, %r10, %rbp
+ mul dinv
+ add %rbp, %rax
+ adc %r11, %rdx
+ mov %rax, %r11
+ mov %rdx, %r13
+ imul d, %rdx
+ sub %rdx, %rbp
+ mov d, %rax
+ add %rbp, %rax
+ cmp %r11, %rbp
+ cmovb %rbp, %rax
+ adc $-1, %r13
+ cmp d, %rax
+ jae L(ufx)
+L(uok): mov %r13, (qp)
+ sub $8, qp
+ dec un
+ mov %r10, %rbp
+ jns L(uloop)
+L(ulast):
+ lea 1(%rax), %r11
+ sal %cl, %rbp
+ mul dinv
+ add %rbp, %rax
+ adc %r11, %rdx
+ mov %rax, %r11
+ mov %rdx, %r13
+ imul d, %rdx
+ sub %rdx, %rbp
+ mov d, %rax
+ add %rbp, %rax
+ cmp %r11, %rbp
+ cmovb %rbp, %rax
+ adc $-1, %r13
+ cmp d, %rax
+ jae L(93)
+L(69): mov %r13, (qp)
+ sub $8, qp
+ jmp L(87)
+
+L(ufx): sub d, %rax
+ inc %r13
+ jmp L(uok)
+
+L(93): sub d, %rax
+ inc %r13
+ jmp L(69)
+
+L(87): mov d, %rbp
+ neg %rbp
+ jmp L(87b)
+
+ ALIGN(16)
+L(floop): C cycK8 cycP6 cycP4
+ lea 1(%rax), %r11 C
+ mul dinv C 0,12
+ add %r11, %rdx C 5
+ mov %rax, %r11 C 4
+ mov %rdx, %r13 C 6
+ imul %rbp, %rdx C 6
+ mov d, %rax C
+ add %rdx, %rax C 10
+ cmp %r11, %rdx C 10
+ cmovb %rdx, %rax C 11
+ adc $-1, %r13 C
+ mov %r13, (qp) C
+ sub $8, qp C
+L(87b): dec fn C
+ jns L(floop) C
+
+ shr %cl, %rax
+L(ret): pop %rbx
+ pop %rbp
+ pop %r12
+ pop %r13
+ ret
+EPILOGUE(mpn_divrem_1)
projects / msp430-gcc.git / blobdiff