1aafd90912
revise anomaly handling by basing things on the compiler not the kconfig defines, so the header is stable and usable outside of the kernel. This also allows us to move some code from preprocessing to compiling (gcc culls dead code) which should help with code quality (readability, catch minor bugs, etc...). Signed-off-by: Mike Frysinger <michael.frysinger@analog.com> Signed-off-by: Bryan Wu <bryan.wu@analog.com>
151 lines
3.7 KiB
ArmAsm
151 lines
3.7 KiB
ArmAsm
/*
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* File: arch/blackfin/lib/memcpy.S
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* Based on:
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* Author:
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*
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* Created:
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* Description: internal version of memcpy(), issued by the compiler
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* to copy blocks of data around.
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* This is really memmove() - it has to be able to deal with
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* possible overlaps, because that ambiguity is when the compiler
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* gives up and calls a function. We have our own, internal version
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* so that we get something we trust, even if the user has redefined
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* the normal symbol.
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*
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* Modified:
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* Copyright 2004-2006 Analog Devices Inc.
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*
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* Bugs: Enter bugs at http://blackfin.uclinux.org/
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see the file COPYING, or write
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* to the Free Software Foundation, Inc.,
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* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <linux/linkage.h>
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/* void *memcpy(void *dest, const void *src, size_t n);
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* R0 = To Address (dest) (leave unchanged to form result)
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* R1 = From Address (src)
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* R2 = count
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*
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* Note: Favours word alignment
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*/
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#ifdef CONFIG_MEMCPY_L1
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.section .l1.text
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#else
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.text
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#endif
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.align 2
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ENTRY(_memcpy)
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CC = R2 <= 0; /* length not positive? */
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IF CC JUMP .L_P1L2147483647; /* Nothing to do */
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P0 = R0 ; /* dst*/
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P1 = R1 ; /* src*/
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P2 = R2 ; /* length */
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/* check for overlapping data */
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CC = R1 < R0; /* src < dst */
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IF !CC JUMP .Lno_overlap;
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R3 = R1 + R2;
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CC = R0 < R3; /* and dst < src+len */
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IF CC JUMP .Lhas_overlap;
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.Lno_overlap:
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/* Check for aligned data.*/
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R3 = R1 | R0;
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R0 = 0x3;
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R3 = R3 & R0;
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CC = R3; /* low bits set on either address? */
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IF CC JUMP .Lnot_aligned;
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/* Both addresses are word-aligned, so we can copy
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at least part of the data using word copies.*/
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P2 = P2 >> 2;
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CC = P2 <= 2;
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IF !CC JUMP .Lmore_than_seven;
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/* less than eight bytes... */
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P2 = R2;
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LSETUP(.Lthree_start, .Lthree_end) LC0=P2;
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R0 = R1; /* setup src address for return */
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.Lthree_start:
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R3 = B[P1++] (X);
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.Lthree_end:
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B[P0++] = R3;
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RTS;
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.Lmore_than_seven:
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/* There's at least eight bytes to copy. */
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P2 += -1; /* because we unroll one iteration */
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LSETUP(.Lword_loops, .Lword_loope) LC0=P2;
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R0 = R1;
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I1 = P1;
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R3 = [I1++];
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#if ANOMALY_05000202
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.Lword_loops:
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[P0++] = R3;
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.Lword_loope:
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R3 = [I1++];
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#else
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.Lword_loops:
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.Lword_loope:
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MNOP || [P0++] = R3 || R3 = [I1++];
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#endif
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[P0++] = R3;
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/* Any remaining bytes to copy? */
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R3 = 0x3;
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R3 = R2 & R3;
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CC = R3 == 0;
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P1 = I1; /* in case there's something left, */
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IF !CC JUMP .Lbytes_left;
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RTS;
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.Lbytes_left: P2 = R3;
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.Lnot_aligned:
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/* From here, we're copying byte-by-byte. */
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LSETUP (.Lbyte_start, .Lbyte_end) LC0=P2;
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R0 = R1; /* Save src address for return */
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.Lbyte_start:
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R1 = B[P1++] (X);
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.Lbyte_end:
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B[P0++] = R1;
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.L_P1L2147483647:
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RTS;
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.Lhas_overlap:
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/* Need to reverse the copying, because the
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* dst would clobber the src.
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* Don't bother to work out alignment for
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* the reverse case.
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*/
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R0 = R1; /* save src for later. */
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P0 = P0 + P2;
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P0 += -1;
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P1 = P1 + P2;
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P1 += -1;
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LSETUP(.Lover_start, .Lover_end) LC0=P2;
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.Lover_start:
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R1 = B[P1--] (X);
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.Lover_end:
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B[P0--] = R1;
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RTS;
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ENDPROC(_memcpy)
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