Imported gcc-4.4.3

[msp430-gcc.git] / gmp / mpn / x86 / pentium4 / copyd.asm

diff --git a/gmp/mpn/x86/pentium4/copyd.asm b/gmp/mpn/x86/pentium4/copyd.asm
new file mode 100644 (file)
index 0000000..491ad60
--- /dev/null
+++ b/gmp/mpn/x86/pentium4/copyd.asm
@@ -0,0 +1,61 @@
+dnl  Pentium-4 mpn_copyd -- copy limb vector, decrementing.
+dnl
+
+dnl  Copyright 1999, 2000, 2001 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 3 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 License
+dnl  along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.
+
+
+dnl  The std/rep/movsl/cld is very slow for small blocks on pentium4.  Its
+dnl  startup time seems to be about 165 cycles.  It then needs 2.6 c/l.
+dnl  We therefore use an open-coded 2 c/l copying loop.
+
+dnl  Ultimately, we may want to use 64-bit movq or 128-bit movdqu in some
+dnl  nifty unrolled arrangement.  Clearly, that could reach much higher
+dnl  speeds, at least for large blocks.
+
+include(`../config.m4')
+
+
+defframe(PARAM_SIZE, 12)
+defframe(PARAM_SRC, 8)
+defframe(PARAM_DST,  4)
+
+       TEXT
+       ALIGN(8)
+
+PROLOGUE(mpn_copyd)
+deflit(`FRAME',0)
+
+       movl    PARAM_SIZE, %ecx
+
+       movl    PARAM_SRC, %eax
+       movl    PARAM_DST, %edx
+       movl    %ebx, PARAM_SIZE
+       addl    $-1, %ecx
+       js      L(end)
+
+L(loop):
+       movl    (%eax,%ecx,4), %ebx
+       movl    %ebx, (%edx,%ecx,4)
+       addl    $-1, %ecx
+
+       jns     L(loop)
+L(end):
+       movl    PARAM_SIZE, %ebx
+       ret
+
+EPILOGUE()