[LLVMdev] "ran out of registers during register allocation"

[Philip Reames]

On 01/02/2015 02:24 PM, reed kotler wrote:
> I'm getting this error in RegAllocFast.cpp in compiling one source 
> file in test-suite as the result of a new Mips fast-isel patch
> I was testing.
>
> It apparently just generates bad code and continues?
>
>   // Nothing we can do. Report an error and keep going with a bad 
> allocation.
>   if (MI->isInlineAsm())
>     MI->emitError("inline assembly requires more registers than 
> available");
>   else
>     MI->emitError("ran out of registers during register allocation");
>
>
> How is it possible to run out of registers during register allocation? 
> Lol.
This seems to be one of the more common errors when you get a MI 
instruction definition wrong.  In particular, I saw this a lot when 
experimenting with various lowering strategies for the statepoint work.  
I'd suggest trying to reduce the example using bugpoint and looking 
closely at the machine instructions.
>
> Reed
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