[LLVMdev] Area for improvement

[Jeff Cohen]

Chris Lattner wrote:

> On Tue, 22 Feb 2005, Jeff Cohen wrote:
>
>> Also, some of what LSR needs to decide is architecture dependent.  
>> For example, it may not want to strength reduce a multiplication 
>> which multiplies by a small power of two, as this is handled by 
>> addressing modes on some architectures.
>
>
> You're right.  However, we can choose to expose information about 
> target parameters through the Target* interfaces that llvm->llvm 
> passes can use as well, so at least this aspect is not a killer issue.
>
> -Chris

The only problem I have with this is that bytecode ought to be platform 
independent.  If I compile on an X86 with complex addressing modes, then 
take the bytecode and translate it to machine code on some RISC, that's 
not fair to the RISC.  Or vice versa.  But then this might already be a 
problem with other optimizations so it might not really introduce 
anything new (does it?).  Or delay all optimization until machine code 
generation time.