[project @ 2000-08-18 15:44:28 by simonmar]

[ghc-hetmet.git] / ghc / rts / gmp / mpn / x86 / k6 / mmx / lshift.asm

diff --git a/ghc/rts/gmp/mpn/x86/k6/mmx/lshift.asm b/ghc/rts/gmp/mpn/x86/k6/mmx/lshift.asm
new file mode 100644 (file)
index 0000000..f1dc83d
--- /dev/null
+++ b/ghc/rts/gmp/mpn/x86/k6/mmx/lshift.asm
@@ -0,0 +1,122 @@
+dnl  AMD K6 mpn_lshift -- mpn left shift.
+dnl 
+dnl  K6: 3.0 cycles/limb
+
+
+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 mp_limb_t mpn_lshift (mp_ptr dst, mp_srcptr src, mp_size_t size,
+C                       unsigned shift);
+C
+C The loop runs at 3 cycles/limb, limited by decoding and by having 3 mmx
+C instructions.  This is despite every second fetch being unaligned.
+
+
+defframe(PARAM_SHIFT,16)
+defframe(PARAM_SIZE, 12)
+defframe(PARAM_SRC,  8)
+defframe(PARAM_DST,  4)
+
+       .text
+       ALIGN(32)
+
+PROLOGUE(mpn_lshift)
+deflit(`FRAME',0)
+
+       C The 1 limb case can be done without the push %ebx, but it's then
+       C still the same speed.  The push is left as a free helping hand for
+       C the two_or_more code.
+
+       movl    PARAM_SIZE, %eax
+       pushl   %ebx                    FRAME_pushl()
+
+       movl    PARAM_SRC, %ebx
+       decl    %eax
+
+       movl    PARAM_SHIFT, %ecx
+       jnz     L(two_or_more)
+
+       movl    (%ebx), %edx            C src limb
+       movl    PARAM_DST, %ebx
+
+       shldl(  %cl, %edx, %eax)        C return value
+
+       shll    %cl, %edx
+
+       movl    %edx, (%ebx)            C dst limb
+       popl    %ebx
+
+       ret
+
+
+       ALIGN(16)       C avoid offset 0x1f
+       nop             C avoid bad cache line crossing
+L(two_or_more):
+       C eax   size-1
+       C ebx   src
+       C ecx   shift
+       C edx
+
+       movl    (%ebx,%eax,4), %edx     C src high limb
+       negl    %ecx
+
+       movd    PARAM_SHIFT, %mm6
+       addl    $32, %ecx               C 32-shift
+
+       shrl    %cl, %edx
+
+       movd    %ecx, %mm7
+       movl    PARAM_DST, %ecx
+
+L(top):
+       C eax   counter, size-1 to 1
+       C ebx   src
+       C ecx   dst
+       C edx   retval
+       C
+       C mm0   scratch
+       C mm6   shift
+       C mm7   32-shift
+
+       movq    -4(%ebx,%eax,4), %mm0
+       decl    %eax
+
+       psrlq   %mm7, %mm0
+
+       movd    %mm0, 4(%ecx,%eax,4)
+       jnz     L(top)
+
+
+       movd    (%ebx), %mm0
+       popl    %ebx
+
+       psllq   %mm6, %mm0
+       movl    %edx, %eax
+
+       movd    %mm0, (%ecx)
+
+       emms
+       ret
+
+EPILOGUE()