deon/gnuk
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

use RBIT instruction of Thumb-2

Browse Source
This commit is contained in:
NIIBE Yutaka
2012-06-05 10:33:50 +09:00
parent 1164ac4d28
commit bfa4952f31
4 changed files with 31 additions and 72 deletions
Download Patch File Download Diff File Expand all files Collapse all files

15
regnual/regnual.c
View File

@@ -147,14 +147,23 @@ static uint32_t result;
static const uint8_t *const mem_info[] = { &_flash_start, &_flash_end, };
static uint32_t fetch (int i)
static uint32_t rbit (uint32_t v)
{
uint32_t r;
r = (mem[i*4] << 24) | (mem[i*4+1] << 16) | (mem[i*4+2] << 8) | mem[i*4+3];
asm ("rbit %0, %1" : "=r" (r) : "r" (v));
return r;
}
static uint32_t fetch (int i)
{
uint32_t v;
v = (mem[i*4+3] << 24) | (mem[i*4+2] << 16) | (mem[i*4+1] << 8) | mem[i*4];
return rbit (v);
}
struct CRC {
__IO uint32_t DR;
__IO uint8_t IDR;
@@ -174,7 +183,7 @@ static uint32_t calc_crc32 (void)
for (i = 0; i < 256/4; i++)
CRC->DR = fetch (i);
return CRC->DR;
return rbit (CRC->DR);
}