diff options
Diffstat (limited to 'libc/string/frv/memcpy.S')
-rw-r--r-- | libc/string/frv/memcpy.S | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/libc/string/frv/memcpy.S b/libc/string/frv/memcpy.S new file mode 100644 index 000000000..63cc523a9 --- /dev/null +++ b/libc/string/frv/memcpy.S @@ -0,0 +1,124 @@ +/* memcpy.S: optimised assembly memcpy + * + * Copyright (C) 2003, 2004 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + + + .text + .p2align 4 + +############################################################################### +# +# void *memcpy(void *to, const char *from, size_t count) +# +# - NOTE: must not use any stack. exception detection performs function return +# to caller's fixup routine, aborting the remainder of the copy +# +############################################################################### + .globl memcpy + .type memcpy,@function +memcpy: + or.p gr8,gr9,gr4 + orcc gr10,gr0,gr0,icc3 + or.p gr10,gr4,gr4 + beqlr icc3,#0 + + # optimise based on best common alignment for to, from & count + andicc.p gr4,#0x1f,gr0,icc0 + setlos #8,gr11 + andicc.p gr4,#0x0f,gr0,icc1 + beq icc0,#0,memcpy_32 + andicc.p gr4,#0x07,gr0,icc0 + beq icc1,#0,memcpy_16 + andicc.p gr4,#0x03,gr0,icc1 + beq icc0,#0,memcpy_8 + andicc.p gr4,#0x01,gr0,icc0 + beq icc1,#0,memcpy_4 + setlos.p #1,gr11 + beq icc0,#0,memcpy_2 + + # do byte by byte copy + sub.p gr8,gr11,gr3 + sub gr9,gr11,gr9 +0: ldubu.p @(gr9,gr11),gr4 + subicc gr10,#1,gr10,icc0 + stbu.p gr4,@(gr3,gr11) + bne icc0,#2,0b + bralr + + # do halfword by halfword copy +memcpy_2: + setlos #2,gr11 + sub.p gr8,gr11,gr3 + sub gr9,gr11,gr9 +0: lduhu.p @(gr9,gr11),gr4 + subicc gr10,#2,gr10,icc0 + sthu.p gr4,@(gr3,gr11) + bne icc0,#2,0b + bralr + + # do word by word copy +memcpy_4: + setlos #4,gr11 + sub.p gr8,gr11,gr3 + sub gr9,gr11,gr9 +0: ldu.p @(gr9,gr11),gr4 + subicc gr10,#4,gr10,icc0 + stu.p gr4,@(gr3,gr11) + bne icc0,#2,0b + bralr + + # do double-word by double-word copy +memcpy_8: + sub.p gr8,gr11,gr3 + sub gr9,gr11,gr9 +0: lddu.p @(gr9,gr11),gr4 + subicc gr10,#8,gr10,icc0 + stdu.p gr4,@(gr3,gr11) + bne icc0,#2,0b + bralr + + # do quad-word by quad-word copy +memcpy_16: + sub.p gr8,gr11,gr3 + sub gr9,gr11,gr9 +0: lddu @(gr9,gr11),gr4 + lddu.p @(gr9,gr11),gr6 + subicc gr10,#16,gr10,icc0 + stdu gr4,@(gr3,gr11) + stdu.p gr6,@(gr3,gr11) + bne icc0,#2,0b + bralr + + # do eight-word by eight-word copy +memcpy_32: + sub.p gr8,gr11,gr3 + sub gr9,gr11,gr9 +0: lddu @(gr9,gr11),gr4 + lddu @(gr9,gr11),gr6 + lddu @(gr9,gr11),gr12 + lddu.p @(gr9,gr11),gr14 + subicc gr10,#32,gr10,icc0 + stdu gr4,@(gr3,gr11) + stdu gr6,@(gr3,gr11) + stdu gr12,@(gr3,gr11) + stdu.p gr14,@(gr3,gr11) + bne icc0,#2,0b + bralr + + .size memcpy, .-memcpy |