forked from Minki/linux
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>
116 lines
2.7 KiB
ArmAsm
116 lines
2.7 KiB
ArmAsm
/*
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* File: arch/blackfin/lib/memcmp.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:
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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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/* int memcmp(const void *s1, const void *s2, size_t n);
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* R0 = First Address (s1)
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* R1 = Second Address (s2)
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* R2 = count (n)
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*
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* Favours word aligned data.
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*/
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.text
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.align 2
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ENTRY(_memcmp)
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I1 = P3;
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P0 = R0; /* P0 = s1 address */
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P3 = R1; /* P3 = s2 Address */
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P2 = R2 ; /* P2 = count */
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CC = R2 <= 7(IU);
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IF CC JUMP .Ltoo_small;
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I0 = R1; /* s2 */
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R1 = R1 | R0; /* OR addresses together */
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R1 <<= 30; /* check bottom two bits */
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CC = AZ; /* AZ set if zero. */
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IF !CC JUMP .Lbytes ; /* Jump if addrs not aligned. */
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P1 = P2 >> 2; /* count = n/4 */
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R3 = 3;
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R2 = R2 & R3; /* remainder */
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P2 = R2; /* set remainder */
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LSETUP (.Lquad_loop_s, .Lquad_loop_e) LC0=P1;
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.Lquad_loop_s:
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#if ANOMALY_05000202
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R0 = [P0++];
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R1 = [I0++];
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#else
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MNOP || R0 = [P0++] || R1 = [I0++];
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#endif
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CC = R0 == R1;
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IF !CC JUMP .Lquad_different;
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.Lquad_loop_e:
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NOP;
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P3 = I0; /* s2 */
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.Ltoo_small:
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CC = P2 == 0; /* Check zero count*/
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IF CC JUMP .Lfinished; /* very unlikely*/
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.Lbytes:
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LSETUP (.Lbyte_loop_s, .Lbyte_loop_e) LC0=P2;
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.Lbyte_loop_s:
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R1 = B[P3++](Z); /* *s2 */
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R0 = B[P0++](Z); /* *s1 */
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CC = R0 == R1;
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IF !CC JUMP .Ldifferent;
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.Lbyte_loop_e:
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NOP;
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.Ldifferent:
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R0 = R0 - R1;
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P3 = I1;
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RTS;
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.Lquad_different:
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/* We've read two quads which don't match.
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* Can't just compare them, because we're
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* a little-endian machine, so the MSBs of
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* the regs occur at later addresses in the
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* string.
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* Arrange to re-read those two quads again,
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* byte-by-byte.
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*/
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P0 += -4; /* back up to the start of the */
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P3 = I0; /* quads, and increase the*/
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P2 += 4; /* remainder count*/
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P3 += -4;
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JUMP .Lbytes;
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.Lfinished:
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R0 = 0;
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P3 = I1;
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RTS;
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ENDPROC(_memcmp)
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