+++ /dev/null
-dnl AMD K6-2 mpn_lshift -- mpn left shift.
-dnl
-dnl K6-2: 1.75 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
-
-defframe(PARAM_SHIFT,16)
-defframe(PARAM_SIZE, 12)
-defframe(PARAM_SRC, 8)
-defframe(PARAM_DST, 4)
-deflit(`FRAME',0)
-
-dnl used after src has been fetched
-define(VAR_RETVAL,`PARAM_SRC')
-
-dnl minimum 9, because unrolled loop can't handle less
-deflit(UNROLL_THRESHOLD, 9)
-
- .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
-
-
-C -----------------------------------------------------------------------------
- ALIGN(16) C avoid offset 0x1f
-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
- cmpl $UNROLL_THRESHOLD-1, %eax
-
- movl %edx, VAR_RETVAL
- jae L(unroll)
-
-
- movd %ecx, %mm7
- movl %eax, %ecx
-
- movl PARAM_DST, %eax
-
-L(simple):
- C eax dst
- C ebx src
- C ecx counter, size-1 to 1
- C edx retval
- C
- C mm0 scratch
- C mm6 shift
- C mm7 32-shift
-
- movq -4(%ebx,%ecx,4), %mm0
-
- psrlq %mm7, %mm0
-
-Zdisp( movd, %mm0, 0,(%eax,%ecx,4))
- loop L(simple)
-
-
- movd (%ebx), %mm0
- popl %ebx
-
- psllq %mm6, %mm0
-
- movd %mm0, (%eax)
- movl %edx, %eax
-
- femms
- ret
-
-
-C -----------------------------------------------------------------------------
- ALIGN(16)
-L(unroll):
- C eax size-1
- C ebx src
- C ecx 32-shift
- C edx retval (but instead VAR_RETVAL is used)
- C
- C mm6 shift
-
- addl $32, %ecx
- movl PARAM_DST, %edx
-
- movd %ecx, %mm7
- subl $7, %eax C size-8
-
- leal (%edx,%eax,4), %ecx C alignment of dst
-
- movq 32-8(%ebx,%eax,4), %mm2 C src high qword
- testb $4, %cl
-
- jz L(dst_aligned)
- psllq %mm6, %mm2
-
- psrlq $32, %mm2
- decl %eax
-
- movd %mm2, 32(%edx,%eax,4) C dst high limb
- movq 32-8(%ebx,%eax,4), %mm2 C new src high qword
-L(dst_aligned):
-
- movq 32-16(%ebx,%eax,4), %mm0 C src second highest qword
-
-
- C This loop is the important bit, the rest is just support for it.
- C Four src limbs are held at the start, and four more will be read.
- C Four dst limbs will be written. This schedule seems necessary for
- C full speed.
- C
- C The use of size-8 lets the loop stop when %eax goes negative and
- C leaves -4 to -1 which can be tested with test $1 and $2.
-
-L(top):
- C eax counter, size-8 step by -4 until <0
- C ebx src
- C ecx
- C edx dst
- C
- C mm0 src next qword
- C mm1 scratch
- C mm2 src prev qword
- C mm6 shift
- C mm7 64-shift
-
- psllq %mm6, %mm2
- subl $4, %eax
-
- movq %mm0, %mm1
- psrlq %mm7, %mm0
-
- por %mm0, %mm2
- movq 24(%ebx,%eax,4), %mm0
-
- psllq %mm6, %mm1
- movq %mm2, 40(%edx,%eax,4)
-
- movq %mm0, %mm2
- psrlq %mm7, %mm0
-
- por %mm0, %mm1
- movq 16(%ebx,%eax,4), %mm0
-
- movq %mm1, 32(%edx,%eax,4)
- jnc L(top)
-
-
- C Now have four limbs in mm2 (prev) and mm0 (next), plus eax mod 4.
- C
- C 8(%ebx) is the next source, and 24(%edx) is the next destination.
- C %eax is between -4 and -1, representing respectively 0 to 3 extra
- C limbs that must be read.
-
-
- testl $2, %eax C testl to avoid bad cache line crossing
- jz L(finish_nottwo)
-
- C Two more limbs: lshift mm2, OR it with rshifted mm0, mm0 becomes
- C new mm2 and a new mm0 is loaded.
-
- psllq %mm6, %mm2
- movq %mm0, %mm1
-
- psrlq %mm7, %mm0
- subl $2, %eax
-
- por %mm0, %mm2
- movq 16(%ebx,%eax,4), %mm0
-
- movq %mm2, 32(%edx,%eax,4)
- movq %mm1, %mm2
-L(finish_nottwo):
-
-
- C lshift mm2, OR with rshifted mm0, mm1 becomes lshifted mm0
-
- testb $1, %al
- psllq %mm6, %mm2
-
- movq %mm0, %mm1
- psrlq %mm7, %mm0
-
- por %mm0, %mm2
- psllq %mm6, %mm1
-
- movq %mm2, 24(%edx,%eax,4)
- jz L(finish_even)
-
-
- C Size is odd, so mm1 and one extra limb to process.
-
- movd (%ebx), %mm0 C src[0]
- popl %ebx
-deflit(`FRAME',0)
-
- movq %mm0, %mm2
- psllq $32, %mm0
-
- psrlq %mm7, %mm0
-
- psllq %mm6, %mm2
- por %mm0, %mm1
-
- movq %mm1, 4(%edx) C dst[1,2]
- movd %mm2, (%edx) C dst[0]
-
- movl VAR_RETVAL, %eax
-
- femms
- ret
-
-
- nop C avoid bad cache line crossing
-L(finish_even):
-deflit(`FRAME',4)
- C Size is even, so only mm1 left to process.
-
- movq %mm1, (%edx) C dst[0,1]
- movl VAR_RETVAL, %eax
-
- popl %ebx
- femms
- ret
-
-EPILOGUE()
projects / ghc-hetmet.git / blobdiff