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Replace the SuperH memcpy() with homebrewed code. The former seems to have

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a subtle failure mode which can result in corruption of memory outside the
bounds of the destination buffer.
This commit is contained in:
scw 2002-10-22 12:25:18 +00:00
parent 64950814bb
commit 03c573236d
1 changed files with 171 additions and 172 deletions
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343
sys/lib/libkern/arch/sh5/memcpy.S
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@ -1,194 +1,193 @@
/* $NetBSD: memcpy.S,v 1.1 2002/10/17 11:53:33 scw Exp $ */
/* $NetBSD: memcpy.S,v 1.2 2002/10/22 12:25:18 scw Exp $ */
/*
* Fast SH5 memcpy, by J"orn Rennecke (joern.rennecke@superh.com)
* Copyright 2002 Wasabi Systems, Inc.
* All rights reserved.
*
* Copyright 2002 SuperH, Inc. All rights reserved
* Written by Steve C. Woodford for Wasabi Systems, Inc.
*
* This software is the property of SuperH, Inc (SuperH) which specifically
* grants the user the right to modify, use and distribute this software
* provided this notice is not removed or altered. All other rights are
* reserved by SuperH.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed for the NetBSD Project by
* Wasabi Systems, Inc.
* 4. The name of Wasabi Systems, Inc. may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* SUPERH MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARD TO
* THIS SOFTWARE. IN NO EVENT SHALL SUPERH BE LIABLE FOR INDIRECT, SPECIAL,
* INCIDENTAL OR CONSEQUENTIAL DAMAGES IN CONNECTION WITH OR ARISING FROM
* THE FURNISHING, PERFORMANCE, OR USE OF THIS SOFTWARE.
*
* So that all may benefit from your experience, please report any problems
* or suggestions about this software to the SuperH Support Center via
* e-mail at softwaresupport@superh.com .
*
* SuperH, Inc.
* 405 River Oaks Parkway
* San Jose
* CA 95134
* USA
*
* The code assumes that any quadword can be read in its
* enirety if at least one byte is included in the copy.
*/
/*
* Slightly modified for use in NetBSD
* by Steve Woodford (scw@wasabisystems.com):
* - LP64 support,
* - tweak register usage, mostly to avoid using r24.
* THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <machine/asm.h>
#define LDUAQ(P,O,D0,D1) ldlo.q P,O,D0; ldhi.q P,O+7,D1
#define STUAQ(P,O,D0,D1) stlo.q P,O,D0; sthi.q P,O+7,D1
#define LDUAL(P,O,D0,D1) ldlo.l P,O,D0; ldhi.l P,O+3,D1
#define STUAL(P,O,D0,D1) stlo.l P,O,D0; sthi.l P,O+3,D1
/*
* void *memcpy(void *dest, void *src, size_t bytes)
*
* This is reasonably fast memcpy() routine.
*
* If the src/dest parameters are suitably aligned, it will try to align
* things such that "alloco" can be used to pre-allocate a cache-line for
* "dest".
*
* If the alignment of src and dest are different, the routine falls back
* to a byte-wise copy. This ain't great, but it serves the caller right.
*
* This algorithm could be improved upon, but I'm wary of trying to be
* too smart, given the lossage experienced with SuperH's memcpy() from
* newlib.
*/
ENTRY(memcpy)
#ifndef _LP64
add.l r2, r63, r2
add.l r2, r63, r7
add.l r3, r63, r3
addz.l r4, r63, r4
#else
add r2, r63, r7
#endif
ld.b r3, 0, r63
pta/l Large, tr0
movi 25, r0
bgeu/u r4, r0, tr0
nsb r4, r0
shlli r0, 5, r0
movi (L1 - L0 + 63*32 + 1) & 0xffff, r1
sub r1, r0, r0
L0: ptrel r0, tr0
add r2, r4, r5
ptabs r18, tr1
add r3, r4, r6
blink tr0, r63
ptabs/u r18, tr0
beq/u r4, r63, tr0 /* Bail now if bytes == 0 */
.balign 8
L1:
/* 0 byte memcpy */
blink tr1, r63
/*
* First, try to align operands. This can only be done if the low 3
* bits match.
*/
pta/l Laligned, tr1
or r7, r3, r1
andi r1, 7, r1
beq/l r1, r63, tr1 /* Operands are already aligned */
L4_7: /* 4..7 byte memcpy cntd. */
stlo.l r2, 0, r0
or r6, r7, r6
sthi.l r5, -1, r6
stlo.l r5, -4, r6
blink tr1, r63
pta/u Lbyte_copy, tr1
xor r7, r3, r0
andi r0, 7, r0 /* Operands misaligned differently? */
bne/u r0, r63, tr1 /* Yup. Fallback to copying byte-wise */
L2_3: /* 2 or 3 byte memcpy cntd. */
st.b r5, -1, r6
blink tr1, r63
add r4, r1, r0
movi 8, r8
bgtu/l r8, r0, tr1
/* 1 byte memcpy */
ld.b r3, 0, r0
st.b r2, 0, r0
blink tr1, r63
L8_15: /* 8..15 byte memcpy cntd. */
stlo.q r2, 0, r0
or r6, r7, r6
sthi.q r5, -1, r6
stlo.q r5, -8, r6
blink tr1, r63
/* 2 or 3 byte memcpy */
ld.b r3, 0, r0
ld.b r2, 0, r63
ld.b r3, 1, r1
st.b r2, 0, r0
pta/l L2_3, tr0
ld.b r6, -1, r6
st.b r2, 1, r1
blink tr0, r63
/* 4 .. 7 byte memcpy */
LDUAL (r3, 0, r0, r1)
pta L4_7, tr0
ldlo.l r6, -4, r7
or r0, r1, r0
sthi.l r2, 3, r0
ldhi.l r6, -1, r6
blink tr0, r63
/* 8 .. 15 byte memcpy */
LDUAQ (r3, 0, r0, r1)
pta L8_15, tr0
ldlo.q r6, -8, r7
or r0, r1, r0
sthi.q r2, 7, r0
ldhi.q r6, -1, r6
blink tr0, r63
/* 16 .. 24 byte memcpy */
LDUAQ (r3, 0, r0, r1)
LDUAQ (r3, 8, r8, r9)
or r0, r1, r0
sthi.q r2, 7, r0
or r8, r9, r8
sthi.q r2, 15, r8
ldlo.q r6, -8, r7
ldhi.q r6, -1, r6
stlo.q r2, 8, r8
stlo.q r2, 0, r0
or r6, r7, r6
sthi.q r5, -1, r6
stlo.q r5, -8, r6
blink tr1, r63
Large:
ld.b r2, 0, r63
pta/l Loop_ua, tr1
ori r3, -8, r7
sub r2, r7, r22
sub r3, r2, r6
add r2, r4, r5
ldlo.q r3, 0, r0
addi r5, -16, r5
movi 64+8, r37 /* could subtract r7 from that. */
stlo.q r2, 0, r0
sthi.q r2, 7, r0
ldx.q r22, r6, r0
bgtu/l r37, r4, tr1
stlo.q r7, 0, r0
sub r8, r1, r0
sub r4, r0, r4
add r7, r0, r7
add r3, r0, r3
addi r5, -48, r37
pta/l Loop_line, tr0
addi r6, 64, r36
addi r6, -24, r19
addi r6, -16, r20
addi r6, -8, r21
Loop_line:
ldx.q r22, r36, r63
alloco r22, 32
addi r22, 32, r22
ldx.q r22, r19, r23
sthi.q r22, -25, r0
ldx.q r22, r20, r36
ldx.q r22, r21, r25
stlo.q r22, -32, r0
ldx.q r22, r6, r0
sthi.q r22, -17, r23
sthi.q r22, -9, r36
sthi.q r22, -1, r25
stlo.q r22, -24, r23
stlo.q r22, -16, r36
stlo.q r22, -8, r25
bgeu r37, r22, tr0
Loop_ua:
addi r22, 8, r22
sthi.q r22, -1, r0
stlo.q r22, -8, r0
ldx.q r22, r6, r0
bgtu/l r5, r22, tr1
add r3, r4, r7
ldlo.q r7, -8, r1
sthi.q r22, 7, r0
ldhi.q r7, -1, r7
ptabs r18, tr1
stlo.q r22, 0, r0
or r1, r7, r1
sthi.q r5, 15, r1
stlo.q r5, 8, r1
/*
* The buffers are quad aligned. Now align src to a 32-byte boundary
* if possible.
*/
Laligned:
movi 0x1f, r6
pta/u Ltrailer, tr2
bgeu/u r6, r4, tr2 /* Jump if less than 32 bytes left */
add r7, r63, r5
add r7, r6, r7
andc r7, r6, r7 /* Round dst up to 32-byte boundary */
sub r7, r5, r1
add r3, r1, r3 /* Adjust src to match */
sub r4, r1, r4
xor r1, r6, r1
addi r1, 2, r1
ptrel/l r1, tr1
blink tr1, r63
ld.q r3, -24, r0
st.q r7, -24, r0
ld.q r3, -16, r0
st.q r7, -16, r0
ld.q r3, -8, r0
st.q r7, -8, r0
/*
* "src" is now aligned to a multiple of 32 bytes
*/
bgeu/u r6, r4, tr2 /* Jump if less than 32 bytes left */
pta/l Lcache_enter, tr1
pta/u Lcache_loop, tr2
ld.q r3, 0, r63 /* Prefetch one cache-line in advance */
alloco r7, 0 /* Allocate one cache-line in advance */
add r7, r4, r5
and r4, r6, r4
andc r5, r6, r5
blink tr1, r63
Lcache_loop:
ld.q r3, 0, r63 /* Prefetch in advance */
alloco r7, 0 /* Allocate one cache-line in advance */
ld.q r3, -32, r19
ld.q r3, -24, r20
ld.q r3, -16, r21
ld.q r3, -8, r22
st.q r7, -32, r19 /* Copy the previous cache-line */
st.q r7, -24, r20
st.q r7, -16, r21
st.q r7, -8, r22
Lcache_enter:
addi r7, 32, r7 /* Next cache-line */
addi r3, 32, r3
bne/l r5, r7, tr2
ld.q r3, -32, r19
ld.q r3, -24, r20
ld.q r3, -16, r21
ld.q r3, -8, r22
st.q r7, -32, r19
st.q r7, -24, r20
st.q r7, -16, r21
st.q r7, -8, r22
/*
* We have, at most, 31 bytes left to deal with.
*/
Ltrailer:
beq/u r4, r63, tr0 /* Return to caller if done. */
add r4, r7, r8
add r4, r3, r9
andi r4, 0x18, r4
add r7, r4, r7
add r3, r4, r3
xori r4, 0x1f, r4
addi r4, 2, r4
ptrel/l r4, tr1
blink tr1, r63
ld.q r3, -24, r0
st.q r7, -24, r0
ld.q r3, -16, r0
st.q r7, -16, r0
ld.q r3, -8, r0
st.q r7, -8, r0
ldhi.q r9, -1, r0
sthi.q r8, -1, r0
blink tr0, r63
/*
* Either the alignment of src/dest is shot to pieces, or we're
* dealing with a misaligned short buffer. Either way, do things
* the Slow Way.
*/
Lbyte_copy:
movi 0, r1
pta/l 1f, tr1
1: ldx.b r3, r1, r0
stx.b r7, r1, r0
addi r1, 1, r1
bne/l r1, r4, tr1
blink tr0, r63