forked from len0rd/rockbox
Assembler optimized copy_read_sectors() gives another speedup of factor 1.4 for aligned and 1.2 for misaligned. Including my previous change the file reading is now nearly twice as fast compared to when I started this. -> Less disk uptime, longer battery life.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4281 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Jörg Hohensohn
parent
0a8fef9a24
commit
cb570b9263
1 changed files with 103 additions and 7 deletions
|
|
@ -162,33 +162,129 @@ static int wait_for_end_of_transfer(void)
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
||||||
|
/*
|
||||||
|
0x090156A8: 0x4F22 sts.l pr,@-r15
|
||||||
|
0x090156AA: 0x6243 mov r4,r2
|
||||||
|
0x090156AC: 0x6023 mov r2,r0
|
||||||
|
0x090156AE: 0xC901 and #0x01,r0
|
||||||
|
0x090156B0: 0x2008 tst r0,r0
|
||||||
|
0x090156B2: 0x8911 bt 0x090156D8
|
||||||
|
0x090156B4: 0x6153 mov r5,r1
|
||||||
|
0x090156B6: 0x311C add r1,r1
|
||||||
|
0x090156B8: 0x6523 mov r2,r5
|
||||||
|
0x090156BA: 0x351C add r1,r5
|
||||||
|
0x090156BC: 0xD30E mov.l @(0x03C,pc),r3 ; 0x090156F8 (0x06104100)
|
||||||
|
0x090156BE: 0x0009 nop
|
||||||
|
|
||||||
|
0x090156C0: 0x6131 mov.w @r3,r1
|
||||||
|
0x090156C2: 0x611D extu.w r1,r1
|
||||||
|
0x090156C4: 0x2210 mov.b r1,@r2
|
||||||
|
0x090156C6: 0x7201 add #0x01,r2
|
||||||
|
0x090156C8: 0x4119 shlr8 r1
|
||||||
|
0x090156CA: 0x2210 mov.b r1,@r2
|
||||||
|
0x090156CC: 0x7201 add #0x01,r2
|
||||||
|
0x090156CE: 0x3252 cmp/hs r5,r2
|
||||||
|
0x090156D0: 0x8BF6 bf 0x090156C0
|
||||||
|
|
||||||
|
0x090156D2: 0xA00F bra 0x090156F4
|
||||||
|
0x090156D4: 0x4F26 lds.l @r15+,pr
|
||||||
|
0x090156D6: 0x0009 nop
|
||||||
|
0x090156D8: 0x6423 mov r2,r4
|
||||||
|
0x090156DA: 0x6153 mov r5,r1
|
||||||
|
0x090156DC: 0x311C add r1,r1
|
||||||
|
0x090156DE: 0x6543 mov r4,r5
|
||||||
|
0x090156E0: 0x351C add r1,r5
|
||||||
|
0x090156E2: 0xD205 mov.l @(0x018,pc),r2 ; 0x090156F8 (0x06104100)
|
||||||
|
|
||||||
|
0x090156E4: 0x6121 mov.w @r2,r1
|
||||||
|
0x090156E6: 0x611F exts.w r1,r1
|
||||||
|
0x090156E8: 0x6118 swap.b r1,r1
|
||||||
|
0x090156EA: 0x2411 mov.w r1,@r4
|
||||||
|
0x090156EC: 0x7402 add #0x02,r4
|
||||||
|
0x090156EE: 0x3452 cmp/hs r5,r4
|
||||||
|
0x090156F0: 0x8BF8 bf 0x090156E4
|
||||||
|
|
||||||
|
0x090156F2: 0x4F26 lds.l @r15+,pr
|
||||||
|
0x090156F4: 0x000B rts
|
||||||
|
0x090156F6: 0x0009 nop
|
||||||
|
0x090156F8: 0x0610 .long 0x06104100 ; 0x090156E0
|
||||||
|
0x090156FA: 0x4100
|
||||||
|
*/
|
||||||
|
|
||||||
|
|
||||||
|
|
||||||
/* the tight loop of ata_read_sectors(), to avoid the whole in IRAM */
|
/* the tight loop of ata_read_sectors(), to avoid the whole in IRAM */
|
||||||
static void copy_read_sectors(unsigned char* buf,
|
static void copy_read_sectors(unsigned char* buf,
|
||||||
int wordcount)
|
int wordcount)
|
||||||
__attribute__ ((section (".icode")));
|
__attribute__ ((section (".icode")));
|
||||||
static void copy_read_sectors(unsigned char* buf, int wordcount)
|
static void copy_read_sectors(unsigned char* buf, int wordcount)
|
||||||
{
|
{
|
||||||
if (wordcount <= 0)
|
unsigned short tmp = 0; /* have to init to prevent warning? */
|
||||||
return; /* should never happen, but to protect my tail loop */
|
|
||||||
|
|
||||||
if ( (unsigned int)buf & 1 )
|
if ( (unsigned int)buf & 1)
|
||||||
{
|
{ /* not 16-bit aligned, copy byte by byte */
|
||||||
unsigned char* bufend = buf + wordcount*2;
|
unsigned char* bufend = buf + wordcount*2;
|
||||||
|
#ifdef PREFER_C
|
||||||
do
|
do
|
||||||
{ /* loop compiles to 8 assembler instructions */
|
{ /* loop compiles to 9 assembler instructions */
|
||||||
unsigned short tmp = ATA_DATA;
|
tmp = ATA_DATA;
|
||||||
*buf++ = tmp & 0xff; /* I assume big endian */
|
*buf++ = tmp & 0xff; /* I assume big endian */
|
||||||
*buf++ = tmp >> 8; /* and don't use the SWAB16 macro */
|
*buf++ = tmp >> 8; /* and don't use the SWAB16 macro */
|
||||||
} while (buf < bufend); /* tail loop is faster */
|
} while (buf < bufend); /* tail loop is faster */
|
||||||
|
#else
|
||||||
|
asm (
|
||||||
|
"mov #1, r0 \n"
|
||||||
|
"loop_b: \n"
|
||||||
|
"mov.w @%1,%0 \n"
|
||||||
|
"mov.b %0,@%2 \n"
|
||||||
|
"shlr8 %0 \n"
|
||||||
|
"mov.b %0,@(r0,%2) \n"
|
||||||
|
"add #0x02,%2 \n"
|
||||||
|
"cmp/hs %3,%2 \n"
|
||||||
|
"bf loop_b \n"
|
||||||
|
: /* outputs */
|
||||||
|
: /* inputs */
|
||||||
|
/* %0 */ "r"(tmp),
|
||||||
|
/* %1 */ "r"(&ATA_DATA),
|
||||||
|
/* %2 */ "r"(buf),
|
||||||
|
/* %3 */ "r"(bufend)
|
||||||
|
: /* trashed */
|
||||||
|
"r0"
|
||||||
|
);
|
||||||
|
#endif
|
||||||
}
|
}
|
||||||
else
|
else
|
||||||
{
|
{ /* 16-bit aligned, can do faster copy */
|
||||||
unsigned short* wbuf = (unsigned short*)buf;
|
unsigned short* wbuf = (unsigned short*)buf;
|
||||||
unsigned short* wbufend = wbuf + wordcount;
|
unsigned short* wbufend = wbuf + wordcount;
|
||||||
|
#ifdef PREFER_C
|
||||||
do
|
do
|
||||||
{ /* loop compiles to 7 assembler instructions */
|
{ /* loop compiles to 7 assembler instructions */
|
||||||
*wbuf = SWAB16(ATA_DATA);
|
*wbuf = SWAB16(ATA_DATA);
|
||||||
} while (++wbuf < wbufend); /* tail loop is faster */
|
} while (++wbuf < wbufend); /* tail loop is faster */
|
||||||
|
#else
|
||||||
|
asm (
|
||||||
|
"mov #2, r0 \n"
|
||||||
|
"loop_w: \n"
|
||||||
|
"mov.w @%1,%0 \n"
|
||||||
|
"swap.b %0,%0 \n"
|
||||||
|
"mov.w %0,@%2 \n"
|
||||||
|
"mov.w @%1,%0 \n" /* unrolled, do one more */
|
||||||
|
"swap.b %0,%0 \n"
|
||||||
|
"mov.w %0,@(r0,%2) \n"
|
||||||
|
"add #0x04,%2 \n"
|
||||||
|
"cmp/hs %3,%2 \n"
|
||||||
|
"bf loop_w \n"
|
||||||
|
: /* outputs */
|
||||||
|
: /* inputs */
|
||||||
|
/* %0 */ "r"(tmp),
|
||||||
|
/* %1 */ "r"(&ATA_DATA),
|
||||||
|
/* %2 */ "r"(wbuf),
|
||||||
|
/* %3 */ "r"(wbufend)
|
||||||
|
: /* trashed */
|
||||||
|
"r0"
|
||||||
|
);
|
||||||
|
#endif
|
||||||
}
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
|
||||||
Loading…
Add table
Add a link
Reference in a new issue