[llvm-commits] [llvm] r92411 - in /llvm/trunk: lib/Transforms/Scalar/InstructionCombining.cpp test/Transforms/InstCombine/load-cmp.ll

Duncan Sands baldrick at free.fr
Sun Jan 3 23:40:01 PST 2010


Hi Chris,

> if ("foobar"[i] == '\0') ...
> 
> which we compile into: if (i == 6), saving a load and 
> materialization of the global address.  This also exposes 
> loop trip count information to later passes in many cases.

nice transform.  However if this is not an inbounds GEP and the index "i" is
64 bits on a 32 bit machine, then there are other possible values for "i",
such as i == 6 + 2^32.

Ciao,

Duncan.



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