; PROLOGUE(submul_1) ; Copyright 2006 Jason Worth Martin ; ; Copyright 2008, 2009 Brian Gladman ; ; This file is part of the GNU MP Library. ; ; The GNU MP Library is free software; you can redistribute it and/or ; modify it under the terms of the GNU Lesser General Public License as ; published by the Free Software Foundation; either version 2.1 of the ; License, or (at your option) any later version. ; ; The GNU MP Library is distributed in the hope that it will be useful, ; but WITHOUT ANY WARRANTY; without even the implied warranty of ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU ; Lesser General Public License for more details. ; ; You should have received a copy of the GNU Lesser General Public ; License along with the GNU MP Library; see the file COPYING.LIB. If ; not, write to the Free Software Foundation, Inc., 51 Franklin Street, ; Fifth Floor, Boston, MA 02110-1301, USA. ; ; CREDITS ; ; The code used here is derived from that provided by ct35z at: ; ; http://www.geocities.jp/ct35z/gmp-core2-en.html ; ; This code is based largely on Pierrick Gaudry's excellent assembly ; support for the AMD64 architecture. (Note that Intel64 and AMD64, ; while using the same instruction set, have very different ; microarchitectures. So, this code performs very poorly on AMD64 ; machines even though it is near-optimal on Intel64.) ; ; Roger Golliver works for Intel and provided insightful improvements ; particularly in using the "lea" instruction to perform additions ; and register-to-register moves. ; ; Jason Worth Martin's excellent assembly support for the Intel64 ; architecture has been used where appropriate. ; ; Eric Bainville has a brilliant exposition of optimizing arithmetic for ; AMD64 (http://www.bealto.it). I adapted many of the ideas he ; describes to Intel64. ; ; Agner Fog is a demigod in the x86 world. If you are reading assembly ; code files and you haven't heard of Agner Fog, then take a minute to ; look over his software optimization manuals (http://www.agner.org/). ; They are superb. ; ; Adapted for use with VC++ and YASM using a special mode in which NASM ; preprocessing is used with AT&T assembler syntax. I am very grateful ; for the support that Peter Johnson (one of the authors of YASM) has ; provided in getting this special YASM mode working. Without his ; support this port would have been a great deal more difficult. ; ; The principle issues that I have had to address is the difference ; between GCC and MSVC in their register saving and parameter passing ; conventions. Registers that have to be preserved across function ; calls are: ; ; GCC: rbx, rbp, r12..r15 ; MSVC: rsi, rdi, rbx, rbp, r12..r15 xmm6..xmm15 ; ; Parameter passing conventions for non floating point parameters: ; ; function( GCC MSVC ; p1, rdi rcx ; p2, rsi rdx ; p3, rdx r8 ; p4, rcx r9 ; p5, r8 [rsp+40] ; p6, r9 [rsp+48] ; ; Care must be taken with 32-bit values in 64-bit register or on the ; stack because the upper 32-bits of such parameters are undefined. ; ; Brian Gladman ; ; Intel64 mpn_addmul_1 -- Multiply a limb vector with a limb and ; add the result to a second limb vector. ; ; Calculate src[size] multiplied by mult[1] and add to /subtract from dst[size] and ; return the carry or borrow from the top of the result ; ; BPL is bytes per limb, which is 8 in the 64-bit code here ; mp_limb_t mpn_submul_1(mp_ptr, mp_ptr, mp_size_t, mp_limb_t) ; mp_limb_t mpn_declsh_n(mp_ptr, mp_ptr, mp_size_t, mp_uint) ; rax rdi rsi rdx rcx ; rax rcx rdx r8 r9 ; %define BPL 8 %define UNROLL_EXPONENT 4 %define UNROLL_SIZE (1 << UNROLL_EXPONENT) %define UNROLL_MASK (UNROLL_SIZE - 1) %define ADDR(p,i,d) (d*BPL)(p, i, BPL) ; Register Usage ; -------- ----- ; rax low word from mul ; rbx ; rcx s2limb ; rdx high word from mul ; rsi s1p ; rdi rp ; rbp Base Pointer ; rsp Stack Pointer ; r8 A_x ; r9 A_y ; r10 A_z ; r11 B_x ; r12 B_y ; r13 B_z ; r14 temp ; r15 index %include "yasm_mac.inc" %define reg_save_list rsi, rdi, r12, r13, r14, r15 %define s2limb rcx %define s1p rsi %define rp rdi %define a_x r8 %define a_y r9 %define a_z r10 %define b_x r11 %define b_y r12 %define b_z r13 %define temp r14 %define index r15 LEAF_PROC mpn_submul_1 xor a_z, a_z jmp entry LEAF_PROC mpn_submul_1c mov a_z, [rsp+0x28] entry: FRAME_PROC ?mpn_atom_submul, 0, reg_save_list mov rdi, rcx mov rsi, rdx xor rdx, rdx mov rdx, r8 mov rcx, r9 lea s1p, [s1p+rdx*8] lea rp, [rp+rdx*8] xor index, index sub index, rdx cmp rdx, 4 jge .6 lea rax, [rel .1] add rax, [rax+rdx*8] jmp rax xalign 8 .1: dq .2 - .1 dq .3 - .1 dq .4 - .1 dq .5 - .1 .2: mov rax, a_z EXIT_PROC reg_save_list .3: mov rax, [s1p+index*8] mul s2limb add rax, a_z adc rdx, 0 mov a_z, [rp+index*8] sub a_z, rax mov rax, 0 mov [rp+index*8], a_z adc rax, rdx EXIT_PROC reg_save_list .4: mov rax, [s1p+index*8] mul s2limb add rax, a_z adc rdx, 0 mov a_z, [rp+index*8] mov a_x, rax mov a_y, rdx mov rax, [s1p+index*8+8] mul s2limb mov b_z, [rp+index*8+8] sub a_z, a_x adc rax, a_y mov [rp+index*8], a_z adc rdx, 0 sub b_z, rax mov rax, 0 mov [rp+index*8+8], b_z adc rax, rdx EXIT_PROC reg_save_list .5: mov rax, [s1p+index*8] mul s2limb add rax, a_z adc rdx, 0 mov a_z, [rp+index*8] mov a_x, rax mov a_y, rdx mov rax, [s1p+index*8+8] mul s2limb mov b_z, [rp+index*8+8] mov b_x, rax mov b_y, rdx mov rax, [s1p+index*8+16] mul s2limb sub a_z, a_x adc b_x, a_y mov [rp+index*8], a_z mov a_z, [rp+index*8+16] adc b_y, 0 sub b_z, b_x adc rax, b_y mov [rp+index*8+8], b_z adc rdx, 0 sub a_z, rax mov rax, 0 mov [rp+index*8+16], a_z adc rax, rdx EXIT_PROC reg_save_list .6: mov temp, rdx test rdx, 1 jz .7 mov rax, [s1p+index*8] mul s2limb add rax, a_z adc rdx, 0 mov a_z, [rp+index*8] mov a_x, rax mov a_y, rdx mov rax, [s1p+index*8+8] mul s2limb mov b_z, [rp+index*8+8] mov b_x, rax mov b_y, rdx jmp .8 .7: mov rax, [s1p+index*8] mul s2limb add rax, a_z adc rdx, 0 mov b_z, [rp+index*8] mov b_x, rax mov b_y, rdx mov rax, [s1p+index*8+8] mul s2limb mov a_z, [rp+index*8+8] mov a_x, rax mov a_y, rdx .8: sub temp, 4 and temp, UNROLL_MASK inc temp mov rax, (.10 - .9) >> UNROLL_EXPONENT mul temp lea rdx, [rel .10] sub rdx, rax mov rax, [s1p+index*8+16] lea index, [index+temp+3-UNROLL_SIZE] jmp rdx %macro seq_1 7 mul s2limb %7 %3, %1 lea %1, [rax] mov rax, [byte s1p+index*8+8*%6] adc %4, %2 mov [byte rp+index*8+8*(%6-3)], %3 mov %3, [byte rp+index*8+8*(%6-1)] lea %2, [rdx] adc %5, 0 %endmacro xalign 16 .9: %assign i 0 %rep 16 %if (i & 1) seq_1 b_x, b_y, b_z, a_x, a_y, i, sub %else seq_1 a_x, a_y, a_z, b_x, b_y, i, sub %endif %assign i i + 1 %endrep .10:add index, UNROLL_SIZE jnz .9 .11:mul s2limb sub a_z, a_x mov [rp+index*8-24], a_z mov a_z, [rp+index*8-8] adc b_x, a_y adc b_y, 0 sub b_z, b_x mov [rp+index*8-16], b_z adc rax, b_y adc rdx, 0 sub a_z, rax mov rax, 0 mov [rp+index*8-8], a_z adc rax, rdx .12:END_PROC reg_save_list end