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[/] [or1k/] [trunk/] [uclinux/] [uClinux-2.0.x/] [arch/] [sparc/] [lib/] [memcpy.S] - Rev 199
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! Fast memmove/memcpy/bcopy! Copyright Australian National University, 1995! This file may be used under the terms of the GNU Public License! Author: Paul Mackerras, September 95! Minor beautifications David S. Miller#include <asm/cprefix.h>.globl C_LABEL(bcopy)C_LABEL(bcopy):mov %o0,%o3mov %o1,%o0mov %o3,%o1.globl C_LABEL(amemmove)C_LABEL(amemmove):.globl C_LABEL(memmove).globl C_LABEL(memcpy)C_LABEL(memmove):C_LABEL(memcpy):save %sp,-96,%spmov %i0,%l7cmp %i0,%i1 ! check for dest within source areableu,a 1fandcc %i0,3,%l1add %i1,%i2,%l0cmp %i0,%l0blu,a Lbackmov %l0,%i1! copying forwards! first get dest to be word-alignedandcc %i0,3,%l11:be,a Lwalign ! if dest already word-alignedcmp %i2,4mov 4,%l2sub %l2,%l1,%l2 ! #bytes until word-alignedsubcc %i2,%l2,%i2ble,a Lend ! not copying enough to get past word bdryaddcc %i2,%l2,%i21:ldub [%i1],%o0 ! copy single bytes until word-alignedadd %i1,1,%i1subcc %l2,1,%l2stb %o0,[%i0]bgt 1badd %i0,1,%i0cmp %i2,4Lwalign: ! dest now word alignedblt,a Lendorcc %i2,%g0,%g0andcc %i1,3,%l0be,a Ldoword ! if dest word aligned wrt srcandcc %i0,4,%g0! yucky cases where we have to shiftmov 4,%l2sub %l2,%l0,%l2 ! address adjustment, used at Lendnsll %l0,3,%l0 ! bit offset = shift left countsll %l2,3,%l1 ! shift right countadd %i1,%l2,%i1 ! round up to next wordld [%i1-4],%o0 ! get first wordandcc %i0,4,%g0 ! get destination double-word alignedbe,a 1fandcc %i1,4,%g0ld [%i1],%o1 ! by constructing and storing one wordadd %i0,4,%i0add %i1,4,%i1sub %i2,4,%i2sll %o0,%l0,%o0srl %o1,%l1,%l6or %o0,%l6,%o0st %o0,[%i0-4]mov %o1,%o0andcc %i1,4,%g0 ! now construct & store pairs of double-words1:bne,a 3f ! if source now not double-word alignedsubcc %i2,4,%i2subcc %i2,16,%i2blt 2fmov %o0,%o14:ldd [%i1],%o2sll %o1,%l0,%o4ldd [%i1+8],%o0add %i0,16,%i0add %i1,16,%i1subcc %i2,16,%i2srl %o2,%l1,%l6or %l6,%o4,%o4sll %o2,%l0,%o5srl %o3,%l1,%l6or %l6,%o5,%o5std %o4,[%i0-16]sll %o3,%l0,%o4srl %o0,%l1,%l6or %l6,%o4,%o4sll %o0,%l0,%o5srl %o1,%l1,%l6or %l6,%o5,%o5bge 4bstd %o4,[%i0-8]2:addcc %i2,12,%i2blt,a Lendnaddcc %i2,4,%i25:ld [%i1],%o2add %i0,4,%i0add %i1,4,%i1subcc %i2,4,%i2sll %o1,%l0,%o0srl %o2,%l1,%o1or %o1,%o0,%o0st %o0,[%i0-4]bge 5bmov %o2,%o1ba Lendnaddcc %i2,4,%i23:blt,a Lendnaddcc %i2,4,%i2ld [%i1],%o1add %i1,4,%i1subcc %i2,16,%i2blt,a 8faddcc %i2,16,%i27:ldd [%i1],%o2sll %o0,%l0,%o4srl %o1,%l1,%l6or %l6,%o4,%o4sll %o1,%l0,%o5ldd [%i1+8],%o0add %i0,16,%i0add %i1,16,%i1subcc %i2,16,%i2srl %o2,%l1,%l6or %l6,%o5,%o5std %o4,[%i0-16]sll %o2,%l0,%o4srl %o3,%l1,%l6or %l6,%o4,%o4sll %o3,%l0,%o5srl %o0,%l1,%l6or %l6,%o5,%o5bge 7bstd %o4,[%i0-8]addcc %i2,16,%i28:sll %o0,%l0,%o4srl %o1,%l1,%l6or %l6,%o4,%o4st %o4,[%i0]add %i0,4,%i0subcc %i2,4,%i2blt,a Lendnaddcc %i2,4,%i2mov %o1,%o0ld [%i1],%o1ba 8badd %i1,4,%i1Ldoword:! here both dest and src are word-aligned! make dest double-word alignedbe,a 1fandcc %i1,4,%g0ld [%i1],%o0add %i0,4,%i0add %i1,4,%i1sub %i2,4,%i2st %o0,[%i0-4]cmp %i2,4blt,a Lendorcc %i2,%g0,%g0andcc %i1,4,%g01:be,a Ldodble ! if source double-word aligned nowsubcc %i2,32,%i2ld [%i1],%o5add %i1,4,%i1subcc %i2,36,%i2blt,a 3fadd %i2,32,%i22:ldd [%i1],%o2add %i1,32,%i1subcc %i2,32,%i2mov %o5,%o0ldd [%i1-24],%o4mov %o2,%o1std %o0,[%i0]mov %o3,%o2ldd [%i1-16],%o0mov %o4,%o3std %o2,[%i0+8]mov %o5,%o2ldd [%i1-8],%o4mov %o0,%o3std %o2,[%i0+16]mov %o1,%o0mov %o4,%o1std %o0,[%i0+24]bge 2badd %i0,32,%i0add %i2,32,%i23:st %o5,[%i0]add %i0,4,%i0subcc %i2,4,%i2blt,a Lendaddcc %i2,4,%i2ld [%i1],%o5ba 3badd %i1,4,%i1Ldodble:! dest and source are both double-word alignedblt,a 2faddcc %i2,28,%i21:ldd [%i1],%o0 ! copy sets of 4 double-wordssubcc %i2,32,%i2ldd [%i1+8],%o2add %i1,32,%i1ldd [%i1-16],%o4add %i0,32,%i0std %o0,[%i0-32]ldd [%i1-8],%o0std %o2,[%i0-24]std %o4,[%i0-16]bge 1bstd %o0,[%i0-8]addcc %i2,28,%i22:blt,a Lendaddcc %i2,4,%i23:ld [%i1],%o0 ! copy wordsadd %i1,4,%i1add %i0,4,%i0subcc %i2,4,%i2bge 3bst %o0,[%i0-4]ba Lendaddcc %i2,4,%i2Lendn:sub %i1,%l2,%i1Lend:ble Loutnop1:ldub [%i1],%o0add %i1,1,%i1subcc %i2,1,%i2stb %o0,[%i0]bgt 1badd %i0,1,%i0ba LoutnopLback: ! Here we have to copy backwardsadd %i0,%i2,%i0! first get dest to be word-alignedandcc %i0,3,%l2 ! #bytes until word-alignedbe,a Lbwal ! if dest already word-alignedcmp %i2,4subcc %i2,%l2,%i2ble,a Lbend ! not copying enough to get past word bdryaddcc %i2,%l2,%i21:ldub [%i1-1],%o0 ! copy single bytes until word-alignedsub %i1,1,%i1subcc %l2,1,%l2stb %o0,[%i0-1]bgt 1bsub %i0,1,%i0cmp %i2,4Lbwal: ! dest now word alignedblt,a Lbendorcc %i2,%g0,%g0andcc %i1,3,%l2be,a Lbword ! if dest word aligned wrt srcandcc %i0,4,%g0! yucky cases where we have to shift! note %l2 used below at Lbendnmov 4,%l0sub %l0,%l2,%l0 ! # bytes to right of src in wordsll %l0,3,%l0 ! bit offset = shift right countsll %l2,3,%l1 ! shift left countsub %i1,%l2,%i1 ! round down to word boundaryld [%i1],%o1 ! get first wordandcc %i0,4,%g0 ! get destination double-word alignedbe,a 1fandcc %i1,4,%g0ld [%i1-4],%o0 ! by constructing and storing one wordsub %i0,4,%i0sub %i1,4,%i1sub %i2,4,%i2srl %o1,%l0,%o1sll %o0,%l1,%l6or %o1,%l6,%o1st %o1,[%i0]mov %o0,%o1andcc %i1,4,%g0 ! now construct & store pairs of double-words1:bne,a 3f ! if source now not double-word alignedsubcc %i2,4,%i2subcc %i2,16,%i2blt 2fmov %o1,%o04:ldd [%i1-8],%o2srl %o0,%l0,%o5ldd [%i1-16],%o0sub %i0,16,%i0sub %i1,16,%i1subcc %i2,16,%i2sll %o3,%l1,%l6or %l6,%o5,%o5srl %o3,%l0,%o4sll %o2,%l1,%l6or %l6,%o4,%o4std %o4,[%i0+8]srl %o2,%l0,%o5sll %o1,%l1,%l6or %l6,%o5,%o5srl %o1,%l0,%o4sll %o0,%l1,%l6or %l6,%o4,%o4bge 4bstd %o4,[%i0]2:addcc %i2,12,%i2blt,a Lbendnaddcc %i2,4,%i25:ld [%i1-4],%o2sub %i0,4,%i0sub %i1,4,%i1subcc %i2,4,%i2srl %o0,%l0,%o0sll %o2,%l1,%o1or %o1,%o0,%o0st %o0,[%i0]bge 5bmov %o2,%o0ba Lbendnaddcc %i2,4,%i23:blt,a Lbendnaddcc %i2,4,%i2ld [%i1-4],%o0sub %i1,4,%i1subcc %i2,16,%i2blt,a 8faddcc %i2,16,%i27:ldd [%i1-8],%o2srl %o1,%l0,%o5sll %o0,%l1,%l6or %l6,%o5,%o5srl %o0,%l0,%o4ldd [%i1-16],%o0sub %i0,16,%i0sub %i1,16,%i1subcc %i2,16,%i2sll %o3,%l1,%l6or %l6,%o4,%o4std %o4,[%i0+8]srl %o3,%l0,%o5sll %o2,%l1,%l6or %l6,%o5,%o5srl %o2,%l0,%o4sll %o1,%l1,%l6or %l6,%o4,%o4bge 7bstd %o4,[%i0]addcc %i2,16,%i28:srl %o1,%l0,%o5sll %o0,%l1,%l6or %l6,%o5,%o5st %o5,[%i0-4]sub %i0,4,%i0subcc %i2,4,%i2blt,a Lbendnaddcc %i2,4,%i2mov %o0,%o1ld [%i1-4],%o0ba 8bsub %i1,4,%i1Lbword:! here both dest and src are word-aligned! make dest double-word alignedbe,a 1fandcc %i1,4,%g0ld [%i1-4],%o0sub %i0,4,%i0sub %i1,4,%i1sub %i2,4,%i2st %o0,[%i0]cmp %i2,4blt,a Lbendorcc %i2,%g0,%g0andcc %i1,4,%g01:be,a Lbdble ! if source double-word aligned nowsubcc %i2,32,%i2ld [%i1-4],%o4sub %i1,4,%i1subcc %i2,36,%i2blt,a 3fadd %i2,32,%i22:ldd [%i1-8],%o2sub %i1,32,%i1subcc %i2,32,%i2mov %o4,%o1ldd [%i1+16],%o4mov %o3,%o0std %o0,[%i0-8]mov %o2,%o3ldd [%i1+8],%o0mov %o5,%o2std %o2,[%i0-16]mov %o4,%o3ldd [%i1],%o4mov %o1,%o2std %o2,[%i0-24]mov %o0,%o1mov %o5,%o0std %o0,[%i0-32]bge 2bsub %i0,32,%i0add %i2,32,%i23:st %o4,[%i0-4]sub %i0,4,%i0subcc %i2,4,%i2blt,a Lbendaddcc %i2,4,%i2ld [%i1-4],%o4ba 3bsub %i1,4,%i1Lbdble:! dest and source are both double-word alignedblt,a 2faddcc %i2,28,%i21:ldd [%i1-8],%o0 ! copy sets of 4 double-wordssubcc %i2,32,%i2ldd [%i1-16],%o2sub %i1,32,%i1ldd [%i1+8],%o4sub %i0,32,%i0std %o0,[%i0+24]ldd [%i1],%o0std %o2,[%i0+16]std %o4,[%i0+8]bge 1bstd %o0,[%i0]addcc %i2,28,%i22:blt,a Lbendaddcc %i2,4,%i23:ld [%i1-4],%o0 ! copy wordssub %i1,4,%i1sub %i0,4,%i0subcc %i2,4,%i2bge 3bst %o0,[%i0]ba Lbendaddcc %i2,4,%i2Lbendn:add %i1,%l2,%i1Lbend:ble Loutnop1:ldub [%i1-1],%o0sub %i1,1,%i1subcc %i2,1,%i2stb %o0,[%i0-1]bgt 1bsub %i0,1,%i0Lout:retrestore %l7,0,%o0
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