On Tue, Sep 2, 2008 at 11:38 AM, Xiaoming Gu (JIRA) <[EMAIL PROTECTED]> wrote:
> [drlvm][jit]generate Mnemonic_LEA LIR for Op_Shladd HIR in IA32
> ---------------------------------------------------------------
>
>                 Key: HARMONY-5965
>                 URL: https://issues.apache.org/jira/browse/HARMONY-5965
>             Project: Harmony
>          Issue Type: Improvement
>          Components: DRLVM
>            Reporter: Xiaoming Gu
>
>
> In IA32 there is a quick (1 cycle) LEA instruction for loading effective 
> address. The function of LEA is a combination of shift-left and addition. For 
> example LEA dst, src, 2, 4 does dst=src<<2+4. It's usually used but not 
> limited in element address calculation for array.
>
> In current Ia32InstCodeSelector.cpp, the function for translating Op_Shladd 
> HIR generates shl and add. Since LEA has the same semantic, we could deploy 
> it to improve performance.

Thanks for the proposal. Which phase do you suggest to implement this
optimization, IR lowering?

Thanks,
xiaofebg

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