+++ /dev/null
-dnl AMD K7 mpn_mul_1 -- mpn by limb multiply.
-dnl
-dnl K7: 3.4 cycles/limb (at 16 limbs/loop).
-
-
-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 8 3.9
-dnl 16 3.4
-dnl 32 3.4
-dnl 64 3.35
-dnl Maximum possible with the current code is 64.
-
-deflit(UNROLL_COUNT, 16)
-
-
-C mp_limb_t mpn_mul_1 (mp_ptr dst, mp_srcptr src, mp_size_t size,
-C mp_limb_t multiplier);
-C mp_limb_t mpn_mul_1c (mp_ptr dst, mp_srcptr src, mp_size_t size,
-C mp_limb_t multiplier, mp_limb_t carry);
-C
-C Multiply src,size by mult and store the result in dst,size.
-C Return the carry limb from the top of the result.
-C
-C mpn_mul_1c() accepts an initial carry for the calculation, it's added into
-C the low limb of the destination.
-C
-C Variations on the unrolled loop have been tried, with the current
-C registers or with the counter on the stack to free up ecx. The current
-C code is the fastest found.
-C
-C An interesting effect is that removing the stores "movl %ebx, disp0(%edi)"
-C from the unrolled loop actually slows it down to 5.0 cycles/limb. Code
-C with this change can be tested on sizes of the form UNROLL_COUNT*n+1
-C without having to change the computed jump. There's obviously something
-C fishy going on, perhaps with what execution units the mul needs.
-
-defframe(PARAM_CARRY, 20)
-defframe(PARAM_MULTIPLIER,16)
-defframe(PARAM_SIZE, 12)
-defframe(PARAM_SRC, 8)
-defframe(PARAM_DST, 4)
-
-defframe(SAVE_EBP, -4)
-defframe(SAVE_EDI, -8)
-defframe(SAVE_ESI, -12)
-defframe(SAVE_EBX, -16)
-deflit(STACK_SPACE, 16)
-
-dnl Must have UNROLL_THRESHOLD >= 2, since the unrolled loop can't handle 1.
-ifdef(`PIC',`
-deflit(UNROLL_THRESHOLD, 7)
-',`
-deflit(UNROLL_THRESHOLD, 5)
-')
-
- .text
- ALIGN(32)
-PROLOGUE(mpn_mul_1c)
-deflit(`FRAME',0)
- movl PARAM_CARRY, %edx
- jmp LF(mpn_mul_1,start_nc)
-EPILOGUE()
-
-
-PROLOGUE(mpn_mul_1)
-deflit(`FRAME',0)
- xorl %edx, %edx C initial carry
-L(start_nc):
- movl PARAM_SIZE, %ecx
- subl $STACK_SPACE, %esp
-deflit(`FRAME', STACK_SPACE)
-
- movl %edi, SAVE_EDI
- movl %ebx, SAVE_EBX
- movl %edx, %ebx
-
- movl %esi, SAVE_ESI
- movl PARAM_SRC, %esi
- cmpl $UNROLL_THRESHOLD, %ecx
-
- movl PARAM_DST, %edi
- movl %ebp, SAVE_EBP
- jae L(unroll)
-
- leal (%esi,%ecx,4), %esi
- leal (%edi,%ecx,4), %edi
- negl %ecx
-
- movl PARAM_MULTIPLIER, %ebp
-
-L(simple):
- C eax scratch
- C ebx carry
- C ecx counter (negative)
- C edx scratch
- C esi src
- C edi dst
- C ebp multiplier
-
- movl (%esi,%ecx,4), %eax
-
- mull %ebp
-
- addl %ebx, %eax
- movl %eax, (%edi,%ecx,4)
- movl $0, %ebx
-
- adcl %edx, %ebx
- incl %ecx
- jnz L(simple)
-
- movl %ebx, %eax
- movl SAVE_EBX, %ebx
- movl SAVE_ESI, %esi
-
- movl SAVE_EDI, %edi
- movl SAVE_EBP, %ebp
- addl $STACK_SPACE, %esp
-
- ret
-
-
-C -----------------------------------------------------------------------------
-C The mov to load the next source limb is done well ahead of the mul, this
-C is necessary for full speed. It leads to one limb handled separately
-C after the loop.
-C
-C When unrolling to 32 or more, an offset of +4 is used on the src pointer,
-C to avoid having an 0x80 displacement in the code for the last limb in the
-C unrolled loop. This is for a fair comparison between 16 and 32 unrolling.
-
-ifelse(eval(UNROLL_COUNT >= 32),1,`
-deflit(SRC_OFFSET,4)
-',`
-deflit(SRC_OFFSET,)
-')
-
- C this is offset 0x62, 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
-deflit(`FRAME', STACK_SPACE)
-
- leal -1(%ecx), %edx C one limb handled at end
- leal -2(%ecx), %ecx C and ecx is one less than edx
- movl %ebp, SAVE_EBP
-
- negl %edx
- shrl $UNROLL_LOG2, %ecx C unrolled loop counter
- movl (%esi), %eax C src low limb
-
- andl $UNROLL_MASK, %edx
- movl PARAM_DST, %edi
-
- movl %edx, %ebp
- shll $4, %edx
-
- C 17 code bytes per limb
-ifdef(`PIC',`
- call L(add_eip_to_edx)
-L(here):
-',`
- leal L(entry) (%edx,%ebp), %edx
-')
- negl %ebp
-
- leal ifelse(UNROLL_BYTES,256,128+) SRC_OFFSET(%esi,%ebp,4), %esi
- leal ifelse(UNROLL_BYTES,256,128) (%edi,%ebp,4), %edi
- movl PARAM_MULTIPLIER, %ebp
-
- jmp *%edx
-
-
-ifdef(`PIC',`
-L(add_eip_to_edx):
- C See README.family about old gas bugs
- leal (%edx,%ebp), %edx
- addl $L(entry)-L(here), %edx
- addl (%esp), %edx
- ret
-')
-
-
-C ----------------------------------------------------------------------------
- ALIGN(32)
-L(top):
- C eax next src limb
- C ebx carry
- C ecx counter
- C edx scratch
- C esi src+4
- C edi dst
- C ebp multiplier
- C
- C 17 code bytes per limb processed
-
-L(entry):
-forloop(i, 0, UNROLL_COUNT-1, `
- deflit(`disp_dst', eval(i*4 ifelse(UNROLL_BYTES,256,-128)))
- deflit(`disp_src', eval(disp_dst + 4-(SRC_OFFSET-0)))
-
- mull %ebp
-
- addl %eax, %ebx
-Zdisp( movl, disp_src,(%esi), %eax)
-Zdisp( movl, %ebx, disp_dst,(%edi))
-
- movl $0, %ebx
- adcl %edx, %ebx
-')
-
- decl %ecx
-
- leal UNROLL_BYTES(%esi), %esi
- leal UNROLL_BYTES(%edi), %edi
- jns L(top)
-
-
-deflit(`disp0', ifelse(UNROLL_BYTES,256,-128))
-
- mull %ebp
-
- addl %eax, %ebx
- movl $0, %eax
- movl SAVE_ESI, %esi
-
- movl %ebx, disp0(%edi)
- movl SAVE_EBX, %ebx
- movl SAVE_EDI, %edi
-
- adcl %edx, %eax
- movl SAVE_EBP, %ebp
- addl $STACK_SPACE, %esp
-
- ret
-
-EPILOGUE()
projects / ghc-hetmet.git / blobdiff