dnl AMD K6 mpn_add/sub_n -- mpn addition or subtraction. dnl Copyright 1999, 2000, 2001, 2002 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 K6: normal 3.25 cycles/limb, in-place 2.75 cycles/limb. 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_add_n mpn_add_nc 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 C (1 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 Instruction decoding limits a normal dst=src1+src2 operation to 3 c/l, and C an in-place dst+=src to 2.5 c/l. The unrolled loops have 1 cycle/loop of C loop control, which with 4 limbs/loop means an extra 0.25 c/l. define(PARAM_CARRY, `FRAME+20(%esp)') define(PARAM_SIZE, `FRAME+16(%esp)') define(PARAM_SRC2, `FRAME+12(%esp)') define(PARAM_SRC1, `FRAME+8(%esp)') define(PARAM_DST, `FRAME+4(%esp)') deflit(`FRAME',0) dnl minimum 5 because the unrolled code can't handle less deflit(UNROLL_THRESHOLD, 5) TEXT ALIGN(32) PROLOGUE(M4_function_nc) movl PARAM_CARRY, %eax jmp L(start) EPILOGUE() PROLOGUE(M4_function_n) xorl %eax, %eax L(start): movl PARAM_SIZE, %ecx pushl %ebx FRAME_pushl() movl PARAM_SRC1, %ebx pushl %edi FRAME_pushl() movl PARAM_SRC2, %edx cmpl $UNROLL_THRESHOLD, %ecx movl PARAM_DST, %edi jae L(unroll) shrl %eax C initial carry flag C offset 0x21 here, close enough to aligned L(simple): C eax scratch C ebx src1 C ecx counter C edx src2 C esi C edi dst C ebp C C The store to (%edi) could be done with a stosl; it'd be smaller C code, but there's no speed gain and a cld would have to be added C (per mpn/x86/README). movl (%ebx), %eax leal 4(%ebx), %ebx M4_inst (%edx), %eax movl %eax, (%edi) leal 4(%edi), %edi leal 4(%edx), %edx loop L(simple) movl $0, %eax popl %edi setc %al popl %ebx ret C ----------------------------------------------------------------------------- L(unroll): C eax carry C ebx src1 C ecx counter C edx src2 C esi C edi dst C ebp cmpl %edi, %ebx pushl %esi je L(inplace) ifdef(`OPERATION_add_n',` cmpl %edi, %edx je L(inplace_reverse) ') movl %ecx, %esi andl $-4, %ecx andl $3, %esi leal (%ebx,%ecx,4), %ebx leal (%edx,%ecx,4), %edx leal (%edi,%ecx,4), %edi negl %ecx shrl %eax ALIGN(32) L(normal_top): C eax counter, qwords, negative C ebx src1 C ecx scratch C edx src2 C esi C edi dst C ebp movl (%ebx,%ecx,4), %eax leal 5(%ecx), %ecx M4_inst -20(%edx,%ecx,4), %eax movl %eax, -20(%edi,%ecx,4) movl 4-20(%ebx,%ecx,4), %eax M4_inst 4-20(%edx,%ecx,4), %eax movl %eax, 4-20(%edi,%ecx,4) movl 8-20(%ebx,%ecx,4), %eax M4_inst 8-20(%edx,%ecx,4), %eax movl %eax, 8-20(%edi,%ecx,4) movl 12-20(%ebx,%ecx,4), %eax M4_inst 12-20(%edx,%ecx,4), %eax movl %eax, 12-20(%edi,%ecx,4) loop L(normal_top) decl %esi jz L(normal_finish_one) js L(normal_done) C two or three more limbs movl (%ebx), %eax M4_inst (%edx), %eax movl %eax, (%edi) movl 4(%ebx), %eax M4_inst 4(%edx), %eax decl %esi movl %eax, 4(%edi) jz L(normal_done) movl $2, %ecx L(normal_finish_one): movl (%ebx,%ecx,4), %eax M4_inst (%edx,%ecx,4), %eax movl %eax, (%edi,%ecx,4) L(normal_done): popl %esi popl %edi movl $0, %eax popl %ebx setc %al ret C ----------------------------------------------------------------------------- ifdef(`OPERATION_add_n',` L(inplace_reverse): C dst==src2 movl %ebx, %edx ') L(inplace): C eax initial carry C ebx C ecx size C edx src C esi C edi dst C ebp leal -1(%ecx), %esi decl %ecx andl $-4, %ecx andl $3, %esi movl (%edx), %ebx C src low limb leal (%edx,%ecx,4), %edx leal (%edi,%ecx,4), %edi negl %ecx shrl %eax ALIGN(32) L(inplace_top): C eax C ebx next src limb C ecx size C edx src C esi C edi dst C ebp M4_inst %ebx, (%edi,%ecx,4) movl 4(%edx,%ecx,4), %eax leal 5(%ecx), %ecx M4_inst %eax, 4-20(%edi,%ecx,4) movl 8-20(%edx,%ecx,4), %eax movl 12-20(%edx,%ecx,4), %ebx M4_inst %eax, 8-20(%edi,%ecx,4) M4_inst %ebx, 12-20(%edi,%ecx,4) movl 16-20(%edx,%ecx,4), %ebx loop L(inplace_top) C now %esi is 0 to 3 representing respectively 1 to 4 limbs more M4_inst %ebx, (%edi) decl %esi jz L(inplace_finish_one) js L(inplace_done) C two or three more limbs movl 4(%edx), %eax movl 8(%edx), %ebx M4_inst %eax, 4(%edi) M4_inst %ebx, 8(%edi) decl %esi movl $2, %ecx jz L(normal_done) L(inplace_finish_one): movl 4(%edx,%ecx,4), %eax M4_inst %eax, 4(%edi,%ecx,4) L(inplace_done): popl %esi popl %edi movl $0, %eax popl %ebx setc %al ret EPILOGUE()