dnl Intel P6 mpn_addmul_1/mpn_submul_1 -- add or subtract mpn multiple. dnl Copyright 1999, 2000, 2001, 2002, 2005 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 cycles/limb C P5: C P6 model 0-8,10-12) 6.44 C P6 model 9 (Banias) C P6 model 13 (Dothan) 6.11 C P4 model 0 (Willamette) C P4 model 1 (?) C P4 model 2 (Northwood) C P4 model 3 (Prescott) C P4 model 4 (Nocona) C K6: C K7: C K8: dnl P6 UNROLL_COUNT cycles/limb dnl 8 6.7 dnl 16 6.35 dnl 32 6.3 dnl 64 6.3 dnl Maximum possible with the current code is 64. deflit(UNROLL_COUNT, 16) define(`OPERATION_submul_1',1) 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_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. C C This code is pretty much the same as the K6 code. The unrolled loop is C the same, but there's just a few scheduling tweaks in the setups and the C simple loop. C C A number of variations have been tried for the unrolled loop, with one or C two carries, and with loads scheduled earlier, but nothing faster than 6 C cycles/limb has been found. ifdef(`PIC',` deflit(UNROLL_THRESHOLD, 5) ',` deflit(UNROLL_THRESHOLD, 5) ') defframe(PARAM_CARRY, 20) defframe(PARAM_MULTIPLIER,16) defframe(PARAM_SIZE, 12) defframe(PARAM_SRC, 8) defframe(PARAM_DST, 4) TEXT ALIGN(32) PROLOGUE(M4_function_1c) pushl %ebx deflit(`FRAME',4) movl PARAM_CARRY, %ebx jmp L(start_nc) EPILOGUE() PROLOGUE(M4_function_1) push %ebx deflit(`FRAME',4) xorl %ebx, %ebx C initial carry L(start_nc): movl PARAM_SIZE, %ecx pushl %esi deflit(`FRAME',8) movl PARAM_SRC, %esi pushl %edi deflit(`FRAME',12) movl PARAM_DST, %edi pushl %ebp deflit(`FRAME',16) cmpl $UNROLL_THRESHOLD, %ecx movl PARAM_MULTIPLIER, %ebp jae L(unroll) C simple loop C this is offset 0x22, so close enough to aligned L(simple): C eax scratch C ebx carry C ecx counter C edx scratch C esi src C edi dst C ebp multiplier movl (%esi), %eax addl $4, %edi mull %ebp addl %ebx, %eax adcl $0, %edx M4_inst %eax, -4(%edi) movl %edx, %ebx adcl $0, %ebx decl %ecx leal 4(%esi), %esi jnz L(simple) popl %ebp popl %edi popl %esi movl %ebx, %eax popl %ebx ret C------------------------------------------------------------------------------ C VAR_JUMP holds the computed jump temporarily because there's not enough C registers when doing the mul for the initial two carry limbs. C C The add/adc for the initial carry in %ebx is necessary only for the C mpn_add/submul_1c entry points. Duplicating the startup code to C eliminiate this for the plain mpn_add/submul_1 doesn't seem like a good C idea. dnl overlapping with parameters already fetched define(VAR_COUNTER,`PARAM_SIZE') define(VAR_JUMP, `PARAM_DST') C this is offset 0x43, so close enough to aligned L(unroll): C eax C ebx initial carry C ecx size C edx C esi src C edi dst C ebp movl %ecx, %edx decl %ecx subl $2, %edx negl %ecx shrl $UNROLL_LOG2, %edx andl $UNROLL_MASK, %ecx movl %edx, VAR_COUNTER movl %ecx, %edx C 15 code bytes per limb ifdef(`PIC',` call L(pic_calc) L(here): ',` shll $4, %edx negl %ecx leal L(entry) (%edx,%ecx,1), %edx ') movl (%esi), %eax C src low limb movl %edx, VAR_JUMP leal ifelse(UNROLL_BYTES,256,128+) 4(%esi,%ecx,4), %esi mull %ebp addl %ebx, %eax C initial carry (from _1c) adcl $0, %edx movl %edx, %ebx C high carry leal ifelse(UNROLL_BYTES,256,128) (%edi,%ecx,4), %edi movl VAR_JUMP, %edx testl $1, %ecx movl %eax, %ecx C low carry cmovnz( %ebx, %ecx) C high,low carry other way around cmovnz( %eax, %ebx) jmp *%edx ifdef(`PIC',` L(pic_calc): shll $4, %edx negl %ecx C See mpn/x86/README about old gas bugs leal (%edx,%ecx,1), %edx addl $L(entry)-L(here), %edx addl (%esp), %edx ret_internal ') C ----------------------------------------------------------- ALIGN(32) L(top): deflit(`FRAME',16) C eax scratch C ebx carry hi C ecx carry lo C edx scratch C esi src C edi dst C ebp multiplier C C VAR_COUNTER loop counter C C 15 code bytes per limb addl $UNROLL_BYTES, %edi L(entry): deflit(CHUNK_COUNT,2) forloop(`i', 0, UNROLL_COUNT/CHUNK_COUNT-1, ` deflit(`disp0', eval(i*4*CHUNK_COUNT ifelse(UNROLL_BYTES,256,-128))) deflit(`disp1', eval(disp0 + 4)) Zdisp( movl, disp0,(%esi), %eax) mull %ebp Zdisp( M4_inst,%ecx, disp0,(%edi)) adcl %eax, %ebx movl %edx, %ecx adcl $0, %ecx movl disp1(%esi), %eax mull %ebp M4_inst %ebx, disp1(%edi) adcl %eax, %ecx movl %edx, %ebx adcl $0, %ebx ') decl VAR_COUNTER leal UNROLL_BYTES(%esi), %esi jns L(top) deflit(`disp0', eval(UNROLL_BYTES ifelse(UNROLL_BYTES,256,-128))) M4_inst %ecx, disp0(%edi) movl %ebx, %eax popl %ebp popl %edi popl %esi popl %ebx adcl $0, %eax ret EPILOGUE()