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Add note about assembly.

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cnlohr
2023-04-25 15:55:59 -04:00
parent 82d5b8daf8
commit 848ad3eeca
1 changed files with 17 additions and 0 deletions
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17
firmware/nixitest1/nixitest1.c
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@@ -128,6 +128,23 @@ static inline uint32_t FastMultiply( uint32_t big_num, uint32_t small_num )
multiplicand>>=1; multiplicand>>=1;
} while( multiplicand ); } while( multiplicand );
return ret; return ret;
// Which is equivelent to the following assembly (If you were curious)
/*
uint32_t ret = 0;
asm volatile( "\n\
.option rvc;\n\
1: andi t0, %[small], 1\n\
beqz t0, 2f\n\
add %[ret], %[ret], %[big]\n\
2: srli %[small], %[small], 1\n\
slli %[big], %[big], 1\n\
bnez %[small], 1b\n\
" :
[ret]"=&r"(ret), [big]"+&r"(big_num), [small]"+&r"(small_num) : :
"t0" );
return ret;
*/
} }
// FYI You can use functions in ram to make them work faster. The .data // FYI You can use functions in ram to make them work faster. The .data