X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Frts%2Fgmp%2Fmpn%2Fx86%2Fk6%2Fk62mmx%2Frshift.asm;fp=ghc%2Frts%2Fgmp%2Fmpn%2Fx86%2Fk6%2Fk62mmx%2Frshift.asm;h=8a8c144241f6d6e35bef8526c9bce0dbaa6b8050;hb=e72806f1683fc7acf7bd10885e8e45ff06d790f1;hp=0000000000000000000000000000000000000000;hpb=a6c4cc3666b15a6392279d492f87861c1f18b2de;p=ghc-hetmet.git diff --git a/ghc/rts/gmp/mpn/x86/k6/k62mmx/rshift.asm b/ghc/rts/gmp/mpn/x86/k6/k62mmx/rshift.asm new file mode 100644 index 0000000..8a8c144 --- /dev/null +++ b/ghc/rts/gmp/mpn/x86/k6/k62mmx/rshift.asm @@ -0,0 +1,285 @@ +dnl AMD K6-2 mpn_rshift -- mpn right 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_rshift (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 Minimum 9, because the unrolled loop can't handle less. +dnl +deflit(UNROLL_THRESHOLD, 9) + + .text + ALIGN(32) + +PROLOGUE(mpn_rshift) +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 + + shrdl( %cl, %edx, %eax) C return value + + shrl %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), %edx C src low limb + negl %ecx + + addl $32, %ecx + movd PARAM_SHIFT, %mm6 + + shll %cl, %edx + cmpl $UNROLL_THRESHOLD-1, %eax + + jae L(unroll) + + + C eax size-1 + C ebx src + C ecx 32-shift + C edx retval + C + C mm6 shift + + movl PARAM_DST, %ecx + leal (%ebx,%eax,4), %ebx + + leal -4(%ecx,%eax,4), %ecx + negl %eax + + C This loop runs at about 3 cycles/limb, which is the amount of + C decoding, and this is despite every second access being unaligned. + +L(simple): + C eax counter, -(size-1) to -1 + C ebx &src[size-1] + C ecx &dst[size-1] + C edx retval + C + C mm0 scratch + C mm6 shift + +Zdisp( movq, 0,(%ebx,%eax,4), %mm0) + incl %eax + + psrlq %mm6, %mm0 + +Zdisp( movd, %mm0, 0,(%ecx,%eax,4)) + jnz L(simple) + + + movq %mm0, (%ecx) + movl %edx, %eax + + popl %ebx + + femms + ret + + +C ----------------------------------------------------------------------------- + ALIGN(16) +L(unroll): + C eax size-1 + C ebx src + C ecx 32-shift + C edx retval + C + C mm6 shift + + addl $32, %ecx + subl $7, %eax C size-8 + + movd %ecx, %mm7 + movl PARAM_DST, %ecx + + movq (%ebx), %mm2 C src low qword + leal (%ebx,%eax,4), %ebx C src end - 32 + + testb $4, %cl + leal (%ecx,%eax,4), %ecx C dst end - 32 + + notl %eax C -(size-7) + jz L(dst_aligned) + + psrlq %mm6, %mm2 + incl %eax + +Zdisp( movd, %mm2, 0,(%ecx,%eax,4)) C dst low limb + movq 4(%ebx,%eax,4), %mm2 C new src low qword +L(dst_aligned): + + movq 12(%ebx,%eax,4), %mm0 C src second lowest qword + nop C avoid bad cache line crossing + + + 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-7) lets the loop stop when %eax becomes >= 0 and + C and leaves 0 to 3 which can be tested with test $1 and $2. + +L(top): + C eax counter, -(size-7) step by +4 until >=0 + C ebx src end - 32 + C ecx dst end - 32 + C edx retval + C + C mm0 src next qword + C mm1 scratch + C mm2 src prev qword + C mm6 shift + C mm7 64-shift + + psrlq %mm6, %mm2 + addl $4, %eax + + movq %mm0, %mm1 + psllq %mm7, %mm0 + + por %mm0, %mm2 + movq 4(%ebx,%eax,4), %mm0 + + psrlq %mm6, %mm1 + movq %mm2, -12(%ecx,%eax,4) + + movq %mm0, %mm2 + psllq %mm7, %mm0 + + por %mm0, %mm1 + movq 12(%ebx,%eax,4), %mm0 + + movq %mm1, -4(%ecx,%eax,4) + ja L(top) C jump if no carry and not zero + + + + C Now have the four limbs in mm2 (low) and mm0 (high), and %eax is 0 + C to 3 representing respectively 3 to 0 further limbs. + + testl $2, %eax C testl to avoid bad cache line crossings + jnz L(finish_nottwo) + + C Two or three extra limbs: rshift mm2, OR it with lshifted mm0, mm0 + C becomes new mm2 and a new mm0 is loaded. + + psrlq %mm6, %mm2 + movq %mm0, %mm1 + + psllq %mm7, %mm0 + addl $2, %eax + + por %mm0, %mm2 + movq 12(%ebx,%eax,4), %mm0 + + movq %mm2, -4(%ecx,%eax,4) + movq %mm1, %mm2 +L(finish_nottwo): + + + testb $1, %al + psrlq %mm6, %mm2 + + movq %mm0, %mm1 + psllq %mm7, %mm0 + + por %mm0, %mm2 + psrlq %mm6, %mm1 + + movq %mm2, 4(%ecx,%eax,4) + jnz L(finish_even) + + + C one further extra limb to process + + movd 32-4(%ebx), %mm0 C src[size-1], most significant limb + popl %ebx + + movq %mm0, %mm2 + psllq %mm7, %mm0 + + por %mm0, %mm1 + psrlq %mm6, %mm2 + + movq %mm1, 32-12(%ecx) C dst[size-3,size-2] + movd %mm2, 32-4(%ecx) C dst[size-1] + + movl %edx, %eax C retval + + femms + ret + + + nop C avoid bad cache line crossing +L(finish_even): + C no further extra limbs + + movq %mm1, 32-8(%ecx) C dst[size-2,size-1] + movl %edx, %eax C retval + + popl %ebx + + femms + ret + +EPILOGUE()