dnl AMD K7 mpn_addmul_1/mpn_submul_1 -- add or subtract mpn multiple. dnl dnl K7: 3.9 cycles/limb. dnl dnl Future: It should be possible to avoid the separate mul after the dnl unrolled loop by moving the movl/adcl to the top. dnl Copyright (C) 1999, 2000 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., 59 Temple Place - dnl Suite 330, Boston, MA 02111-1307, USA. include(`../config.m4') dnl K7: UNROLL_COUNT cycles/limb dnl 4 4.42 dnl 8 4.16 dnl 16 3.9 dnl 32 3.9 dnl 64 3.87 dnl Maximum possible with the current code is 64. deflit(UNROLL_COUNT, 16) ifdef(`OPERATION_addmul_1',` define(M4_inst, addl) define(M4_function_1, mpn_addmul_1) define(M4_function_1c, mpn_addmul_1c) define(M4_description, add it to) define(M4_desc_retval, carry) ',`ifdef(`OPERATION_submul_1',` define(M4_inst, subl) define(M4_function_1, mpn_submul_1) define(M4_function_1c, mpn_submul_1c) define(M4_description, subtract it from) define(M4_desc_retval, borrow) ',`m4_error(`Need OPERATION_addmul_1 or OPERATION_submul_1 ')')') MULFUNC_PROLOGUE(mpn_addmul_1 mpn_addmul_1c mpn_submul_1 mpn_submul_1c) C mp_limb_t M4_function_1 (mp_ptr dst, mp_srcptr src, mp_size_t size, C mp_limb_t mult); C mp_limb_t M4_function_1c (mp_ptr dst, mp_srcptr src, mp_size_t size, C mp_limb_t mult, mp_limb_t carry); C C Calculate src,size multiplied by mult and M4_description dst,size. C Return the M4_desc_retval limb from the top of the result. ifdef(`PIC',` deflit(UNROLL_THRESHOLD, 9) ',` deflit(UNROLL_THRESHOLD, 6) ') defframe(PARAM_CARRY, 20) defframe(PARAM_MULTIPLIER,16) defframe(PARAM_SIZE, 12) defframe(PARAM_SRC, 8) defframe(PARAM_DST, 4) deflit(`FRAME',0) defframe(SAVE_EBX, -4) defframe(SAVE_ESI, -8) defframe(SAVE_EDI, -12) defframe(SAVE_EBP, -16) deflit(SAVE_SIZE, 16) .text ALIGN(32) PROLOGUE(M4_function_1) movl PARAM_SIZE, %edx movl PARAM_SRC, %eax xorl %ecx, %ecx decl %edx jnz LF(M4_function_1c,start_1) movl (%eax), %eax movl PARAM_DST, %ecx mull PARAM_MULTIPLIER M4_inst %eax, (%ecx) adcl $0, %edx movl %edx, %eax ret EPILOGUE() ALIGN(16) PROLOGUE(M4_function_1c) movl PARAM_SIZE, %edx movl PARAM_SRC, %eax decl %edx jnz L(more_than_one_limb) movl (%eax), %eax movl PARAM_DST, %ecx mull PARAM_MULTIPLIER addl PARAM_CARRY, %eax adcl $0, %edx M4_inst %eax, (%ecx) adcl $0, %edx movl %edx, %eax ret C offset 0x44 so close enough to aligned L(more_than_one_limb): movl PARAM_CARRY, %ecx L(start_1): C eax src C ecx initial carry C edx size-1 subl $SAVE_SIZE, %esp deflit(`FRAME',16) movl %ebx, SAVE_EBX movl %esi, SAVE_ESI movl %edx, %ebx C size-1 movl PARAM_SRC, %esi movl %ebp, SAVE_EBP cmpl $UNROLL_THRESHOLD, %edx movl PARAM_MULTIPLIER, %ebp movl %edi, SAVE_EDI movl (%esi), %eax C src low limb movl PARAM_DST, %edi ja L(unroll) C simple loop leal 4(%esi,%ebx,4), %esi C point one limb past last leal (%edi,%ebx,4), %edi C point at last limb negl %ebx C The movl to load the next source limb is done well ahead of the C mul. This is necessary for full speed, and leads to one limb C handled separately at the end. L(simple): C eax src limb C ebx loop counter C ecx carry limb C edx scratch C esi src C edi dst C ebp multiplier mull %ebp addl %eax, %ecx adcl $0, %edx M4_inst %ecx, (%edi,%ebx,4) movl (%esi,%ebx,4), %eax adcl $0, %edx incl %ebx movl %edx, %ecx jnz L(simple) mull %ebp movl SAVE_EBX, %ebx movl SAVE_ESI, %esi movl SAVE_EBP, %ebp addl %eax, %ecx adcl $0, %edx M4_inst %ecx, (%edi) adcl $0, %edx movl SAVE_EDI, %edi addl $SAVE_SIZE, %esp movl %edx, %eax ret C ----------------------------------------------------------------------------- ALIGN(16) L(unroll): C eax src low limb C ebx size-1 C ecx carry C edx size-1 C esi src C edi dst C ebp multiplier dnl overlapping with parameters no longer needed define(VAR_COUNTER,`PARAM_SIZE') define(VAR_JUMP, `PARAM_MULTIPLIER') subl $2, %ebx C (size-2)-1 decl %edx C size-2 shrl $UNROLL_LOG2, %ebx negl %edx movl %ebx, VAR_COUNTER andl $UNROLL_MASK, %edx movl %edx, %ebx shll $4, %edx ifdef(`PIC',` call L(pic_calc) L(here): ',` leal L(entry) (%edx,%ebx,1), %edx ') negl %ebx movl %edx, VAR_JUMP mull %ebp addl %eax, %ecx C initial carry, becomes low carry adcl $0, %edx testb $1, %bl movl 4(%esi), %eax C src second limb leal ifelse(UNROLL_BYTES,256,128+) 8(%esi,%ebx,4), %esi leal ifelse(UNROLL_BYTES,256,128) (%edi,%ebx,4), %edi movl %edx, %ebx C high carry cmovnz( %ecx, %ebx) C high,low carry other way around cmovnz( %edx, %ecx) jmp *VAR_JUMP ifdef(`PIC',` L(pic_calc): C See README.family about old gas bugs leal (%edx,%ebx,1), %edx addl $L(entry)-L(here), %edx addl (%esp), %edx ret ') C ----------------------------------------------------------------------------- C This code uses a "two carry limbs" scheme. At the top of the loop the C carries are ebx=lo, ecx=hi, then they swap for each limb processed. For C the computed jump an odd size means they start one way around, an even C size the other. Either way one limb is handled separately at the start of C the loop. C C The positioning of the movl to load the next source limb is important. C Moving it after the adcl with a view to avoiding a separate mul at the end C of the loop slows the code down. ALIGN(32) L(top): C eax src limb C ebx carry high C ecx carry low C edx scratch C esi src+8 C edi dst C ebp multiplier C C VAR_COUNTER loop counter C C 17 bytes each limb 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)) mull %ebp Zdisp( M4_inst,%ecx, disp0,(%edi)) movl $0, %ecx adcl %eax, %ebx Zdisp( movl, disp0,(%esi), %eax) adcl %edx, %ecx mull %ebp M4_inst %ebx, disp1(%edi) movl $0, %ebx adcl %eax, %ecx movl disp1(%esi), %eax adcl %edx, %ebx ') decl VAR_COUNTER leal UNROLL_BYTES(%esi), %esi leal UNROLL_BYTES(%edi), %edi jns L(top) C eax src limb C ebx carry high C ecx carry low C edx C esi C edi dst (points at second last limb) C ebp multiplier deflit(`disp0', ifelse(UNROLL_BYTES,256,-128)) deflit(`disp1', eval(disp0-0 + 4)) mull %ebp M4_inst %ecx, disp0(%edi) movl SAVE_EBP, %ebp adcl %ebx, %eax movl SAVE_EBX, %ebx movl SAVE_ESI, %esi adcl $0, %edx M4_inst %eax, disp1(%edi) movl SAVE_EDI, %edi adcl $0, %edx addl $SAVE_SIZE, %esp movl %edx, %eax ret EPILOGUE()