Changes between Version 19 and Version 20 of Commentary/Compiler/NewCodeGenStupidity


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Timestamp:
Apr 16, 2011 7:29:11 PM (4 years ago)
Author:
ezyang
Comment:

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  • Commentary/Compiler/NewCodeGenStupidity

    v19 v20  
    99~~At least one major culprit for this is `allocDynClosure`, described in Note `Return a LocalReg`; this pins down the value of the `CmmExpr` to be something for one particular time, but for a vast majority of use-cases the expression is used immediately afterwards. Actually, this is mostly my patches fault, because the extra rewrite means that the inline pass is broken.~~ Fixed in latest version of the pass; we don't quite manage to inline enough but there's only one extra temporary. 
    1010 
    11 Another cause of all of these temporary variables is that the new code generator immediately assigns any variables that were on the stack to temporaries immediately upon entry to a function. 
     11Another cause of all of these temporary variables is that the new code generator immediately assigns any variables that were on the stack to temporaries immediately upon entry to a function. This is on purpose. The idea is we optimize these temporary variables away. 
    1212 
    1313== Rewriting stacks ==