[LLVMdev] JIT machine code deletion

[Chris Lattner]

On Fri, 12 May 2006, Ralph Corderoy wrote:
>> If you don't *know* that all (e.g.) function pointers to this code are
>> dead (which means that execution could come back to the function), you
>> should use the ExecutionEngine::recompileAndRelinkFunction(F) method.
>
> recompileAndRelinkFunction() overwrites the old machine code with a
> branch to the new.  Is it always guaranteed that there's space to write
> the new branch instructions?

Yes.

> A quick look suggests the x86 takes five
> bytes, PowerPC 16,

PPC should be 4 bytes in the normal case.  It is up to the backend to 
implement this API correctly... if it doesn't, that's a bug: please 
report it!

-Chris

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