dnl AMD K7 mpn_add_n/mpn_sub_n -- mpn add or subtract. dnl Copyright 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc. dnl 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 dnl modify it under the terms of the GNU Lesser General Public License as dnl published by the Free Software Foundation; either version 2.1 of the dnl License, or (at your option) any later version. dnl dnl The GNU MP Library is distributed in the hope that it will be useful, dnl but WITHOUT ANY WARRANTY; without even the implied warranty of dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU dnl Lesser General Public License for more details. dnl dnl You should have received a copy of the GNU Lesser General Public dnl License along with the GNU MP Library; see the file COPYING.LIB. If dnl not, write to the Free Software Foundation, Inc., 51 Franklin Street, dnl Fifth Floor, Boston, MA 02110-1301, USA. include(`../config.m4') C K7: 1.64 cycles/limb (at 16 limbs/loop). dnl K7: UNROLL_COUNT cycles/limb dnl 8 1.9 dnl 16 1.64 dnl 32 1.7 dnl 64 2.0 dnl Maximum possible with the current code is 64. deflit(UNROLL_COUNT, 16) define(`OPERATION_sub_n',1) ifdef(`OPERATION_add_n', ` define(M4_inst, adcl) define(M4_function_n, mpn_add_n) define(M4_function_nc, mpn_add_nc) define(M4_description, add) ',`ifdef(`OPERATION_sub_n', ` define(M4_inst, sbbl) define(M4_function_n, mpn_sub_n) define(M4_function_nc, mpn_sub_nc) define(M4_description, subtract) ',`m4_error(`Need OPERATION_add_n or OPERATION_sub_n ')')') MULFUNC_PROLOGUE(mpn_sub_n mpn_sub_nc) C mp_limb_t M4_function_n (mp_ptr dst, mp_srcptr src1, mp_srcptr src2, C mp_size_t size); C mp_limb_t M4_function_nc (mp_ptr dst, mp_srcptr src1, mp_srcptr src2, C mp_size_t size, mp_limb_t carry); C C Calculate src1,size M4_description src2,size, and store the result in C dst,size. The return value is the carry bit from the top of the result (1 C or 0). C C The _nc version accepts 1 or 0 for an initial carry into the low limb of C the calculation. Note values other than 1 or 0 here will lead to garbage C results. C C This code runs at 1.64 cycles/limb, which might be the best possible with C plain integer operations. Each limb is 2 loads and 1 store, any 2 of C which can be done each cycle, leading to 1.5 c/l. dnl Must have UNROLL_THRESHOLD >= 2, since the unrolled loop can't handle 1. ifdef(`PIC',` deflit(UNROLL_THRESHOLD, 8) ',` deflit(UNROLL_THRESHOLD, 8) ') defframe(PARAM_CARRY,20) defframe(PARAM_SIZE, 16) defframe(PARAM_SRC2, 12) defframe(PARAM_SRC1, 8) defframe(PARAM_DST, 4) defframe(SAVE_EBP, -4) defframe(SAVE_ESI, -8) defframe(SAVE_EBX, -12) defframe(SAVE_EDI, -16) deflit(STACK_SPACE, 16) TEXT ALIGN(32) deflit(`FRAME',0) PROLOGUE(M4_function_nc) movl PARAM_CARRY, %eax jmp L(start) EPILOGUE() PROLOGUE(M4_function_n) xorl %eax, %eax C carry L(start): movl PARAM_SIZE, %ecx subl $STACK_SPACE, %esp deflit(`FRAME',STACK_SPACE) movl %edi, SAVE_EDI movl %ebx, SAVE_EBX cmpl $UNROLL_THRESHOLD, %ecx movl PARAM_SRC2, %edx movl PARAM_SRC1, %ebx jae L(unroll) movl PARAM_DST, %edi leal (%ebx,%ecx,4), %ebx leal (%edx,%ecx,4), %edx leal (%edi,%ecx,4), %edi negl %ecx shrl %eax C This loop in in a single 16 byte code block already, so no C alignment necessary. L(simple): C eax scratch C ebx src1 C ecx counter C edx src2 C esi C edi dst C ebp movl (%ebx,%ecx,4), %eax M4_inst (%edx,%ecx,4), %eax movl %eax, (%edi,%ecx,4) incl %ecx jnz L(simple) movl $0, %eax movl SAVE_EDI, %edi movl SAVE_EBX, %ebx setc %al addl $STACK_SPACE, %esp ret C ----------------------------------------------------------------------------- C This is at 0x55, close enough to aligned. L(unroll): deflit(`FRAME',STACK_SPACE) movl %ebp, SAVE_EBP andl $-2, %ecx C size low bit masked out andl $1, PARAM_SIZE C size low bit kept movl %ecx, %edi decl %ecx movl PARAM_DST, %ebp shrl $UNROLL_LOG2, %ecx negl %edi movl %esi, SAVE_ESI andl $UNROLL_MASK, %edi ifdef(`PIC',` call L(pic_calc) L(here): ',` leal L(entry) (%edi,%edi,8), %esi C 9 bytes per ') negl %edi shrl %eax leal ifelse(UNROLL_BYTES,256,128) (%ebx,%edi,4), %ebx leal ifelse(UNROLL_BYTES,256,128) (%edx,%edi,4), %edx leal ifelse(UNROLL_BYTES,256,128) (%ebp,%edi,4), %edi jmp *%esi ifdef(`PIC',` L(pic_calc): C See mpn/x86/README about old gas bugs leal (%edi,%edi,8), %esi addl $L(entry)-L(here), %esi addl (%esp), %esi ret_internal ') C ----------------------------------------------------------------------------- ALIGN(32) L(top): C eax zero C ebx src1 C ecx counter C edx src2 C esi scratch (was computed jump) C edi dst C ebp scratch leal UNROLL_BYTES(%edx), %edx L(entry): deflit(CHUNK_COUNT, 2) forloop(i, 0, UNROLL_COUNT/CHUNK_COUNT-1, ` deflit(`disp0', eval(i*CHUNK_COUNT*4 ifelse(UNROLL_BYTES,256,-128))) deflit(`disp1', eval(disp0 + 4)) Zdisp( movl, disp0,(%ebx), %esi) movl disp1(%ebx), %ebp Zdisp( M4_inst,disp0,(%edx), %esi) Zdisp( movl, %esi, disp0,(%edi)) M4_inst disp1(%edx), %ebp movl %ebp, disp1(%edi) ') decl %ecx leal UNROLL_BYTES(%ebx), %ebx leal UNROLL_BYTES(%edi), %edi jns L(top) mov PARAM_SIZE, %esi movl SAVE_EBP, %ebp movl $0, %eax decl %esi js L(even) movl (%ebx), %ecx M4_inst UNROLL_BYTES(%edx), %ecx movl %ecx, (%edi) L(even): movl SAVE_EDI, %edi movl SAVE_EBX, %ebx setc %al movl SAVE_ESI, %esi addl $STACK_SPACE, %esp ret EPILOGUE()