[LLVMdev] canonicalizing add in constant expressions

[Chris Lattner]

On Fri, 2 May 2008, Jay Foad wrote:
> I wrote some code that fell over when it encountered this ConstantExpr:
>  i32 add (i32 24, i32 ptrtoint ([20 x %"struct.stlpmtx_std::string"]*
> @_ZN12BulletMLNode11name2stringE to i32)))
>
> because it expected the LHS of the add to be another ConstantExpr. (This is
> the first time that bit of code has fallen over, despite having compiled
> thousands of test cases and many megabytes of C and C++ source, so constant
> expressions like this must at least be pretty rare.)
>
> Is there a rule, or a convention, that the plain old constant should go on
> the RHS of an add like this? If so, I'll try to track down what created this
> constant expression. Otherwise I won't bother!

The compiler shouldn't crash, VMCore or ConstantFolding in this case 
(which I assume is what is crashing) should do the canonicalization. 
Please file a bug!

-Chris

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