[llvm-commits] [llvm] r154265 - in /llvm/trunk: lib/CodeGen/SelectionDAG/DAGCombiner.cpp test/CodeGen/ARM/vdiv_combine.ll test/CodeGen/X86/fdiv.ll

Duncan Sands baldrick at free.fr
Sun Apr 8 10:51:22 PDT 2012


Hi Benjamin,

>>> One thing to keep in mind is that we don't want to turn fdivs into fmuls with a denormal number. Denormals may be disabled on the CPU (ops always return 0.0), in other cases they are just painfully slow.
>>
>> how to tell if the reciprocal is denormal?  I don't immediately see an APFloat
>> method for that.
>
> I guess it needs a new method, there seems to be no way to check it from the outside :(

is it actually possible for a reciprocal to be denormal?

Ciao, Duncan.



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