[llvm-commits] [llvm] r72325 - in /llvm/trunk: include/llvm/CodeGen/SelectionDAG.h lib/CodeGen/SelectionDAG/LegalizeVectorOps.cpp lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp

[Dan Gohman]

On May 25, 2009, at 4:12 PM, Chris Lattner wrote:

>>
>>
>> +// This file implements the SelectionDAG::LegalizeVectors method.
>>
>> +//
>>
>> +// The vector legalizer looks for vector operations which might
>>
>> need to be
>>
>> +// unrolled and legalizes them.
>>
>
> s/unroll/scalarize/g?  This should never do any "splitting" of
> vectors, right?

No; unrolling is different than scalarizing, in Legalize jargon.
Scalarizing is turning a single-element vector with an illegal
type into a scalar. Unrolling is turning a (potentially)
multiple-element vector with a legal type into a flock of scalars
in order to perform an operation on them which is not legal on
the vector type.

Feel free to suggest a better name if you can think of one that
doesn't involve the words "split", "scalarize", or "expand". :-)

Dan