[LLVMdev] X86TargetLowering::LowerToBT

[Chris Sears]

Which BTQ? There are three flavors.

BTQ reg/reg
BTQ reg/mem
BTQ reg/imm

I can imagine that the reg/reg and especially the reg/mem versions would be
slow. However the shrq/and versions *with the same operands* would be slow
as well. There's even a compiler comment about the reg/mem version saying
"this is for disassembly only".

But I doubt BTQ reg/imm would be microcoded.


-- 
Ite Ursi
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