On Wed, 15 Jun 2005 [email protected] wrote:
> In find_first_bit() there exists this the sequence:
>
> shll $3,%%edi
> addl %%edi,%%eax
>
> LEA knows how to multiply by small powers of 2 and add all in one shot very
> efficiently:
>
> leal (%%eax,%%edi,8),%%eax
Be careful about model-specific penalties from using certain address
modes and AGIs when using "lea" for such calculations.
Maciej
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