Reorganisation of the source tree

[ghc-hetmet.git] / rts / gmp / mpn / x86 / copyi.asm

diff --git a/rts/gmp/mpn/x86/copyi.asm b/rts/gmp/mpn/x86/copyi.asm
new file mode 100644 (file)
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+++ b/rts/gmp/mpn/x86/copyi.asm
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+dnl  x86 mpn_copyi -- copy limb vector, incrementing.
+
+
+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')
+
+
+C void mpn_copyi (mp_ptr dst, mp_srcptr src, mp_size_t size);
+C
+C Copy src,size to dst,size, working from low to high addresses.
+C
+C The code here is very generic and can be expected to be reasonable on all
+C the x86 family.
+C
+C P5 - 1.0 cycles/limb.
+C
+C P6 - 0.75 cycles/limb.  An MMX based copy was tried, but was found to be
+C      slower than a rep movs in all cases.  The fastest MMX found was 0.8
+C      cycles/limb (when fully aligned).  A rep movs seems to have a startup
+C      time of about 15 cycles, but doing something special for small sizes
+C      could lead to a branch misprediction that would destroy any saving.
+C      For now a plain rep movs seems ok for P6.
+
+defframe(PARAM_SIZE,12)
+defframe(PARAM_SRC, 8)
+defframe(PARAM_DST, 4)
+deflit(`FRAME',0)
+
+       .text
+       ALIGN(32)
+
+       C eax   saved esi
+       C ebx
+       C ecx   counter
+       C edx   saved edi
+       C esi   src
+       C edi   dst
+       C ebp
+
+PROLOGUE(mpn_copyi)
+
+       movl    PARAM_SIZE, %ecx
+       movl    %esi, %eax
+
+       movl    PARAM_SRC, %esi
+       movl    %edi, %edx
+
+       movl    PARAM_DST, %edi
+
+       cld     C better safe than sorry, see mpn/x86/README.family
+
+       rep
+       movsl
+
+       movl    %eax, %esi
+       movl    %edx, %edi
+
+       ret
+
+EPILOGUE()