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Assembler optimised swap32 for ARM.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@9072 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Thom Johansen 2006-03-17 02:05:39 +00:00
parent 310d191f06
commit 70ab7fc4e9
1 changed files with 10 additions and 3 deletions
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13
firmware/export/system.h
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@ -463,9 +463,16 @@ static inline unsigned long swap32(unsigned long value)
result[ 7.. 0] = value[31..24];
*/
{
unsigned long hi = swap16(value >> 16);
unsigned long lo = swap16(value & 0xffff);
return (lo << 16) | hi;
unsigned int tmp;
asm volatile (
"eor %1, %0, %0, ror #16 \n\t"
"bic %1, %1, #0xff0000 \n\t"
"mov %0, %0, ror #8 \n\t"
"eor %0, %0, %1, lsr #8 \n\t"
: "+r" (value), "=r" (tmp)
);
return value;
}