[llvm-commits] [llvm] r58351 - in /llvm/trunk: lib/Transforms/Scalar/InstructionCombining.cpp test/Transforms/InstCombine/logical-select.ll

[Dan Gohman]

On Oct 28, 2008, at 4:13 PM, Chris Lattner wrote:

> On Oct 28, 2008, at 3:39 PM, Dan Gohman wrote:
>> URL: http://llvm.org/viewvc/llvm-project?rev=58351&view=rev
>> Log:
>> (A & sext(C)) | (B & ~sext(C)  ->  C ? A : B
>
> Is sext from i1 really the canonical form or is select c, -1, 0?  If
> so, do we turn "c ? -1 : 0" into sext(c)?  If not, do we already do
> this xform for the ?: form?


There doesn't appear to be a canonical form yet. sext i1 to i32 is
not converted to select, and select x, -1, 0 is not converted to sext.

Also, we don't do the above xform for the ?: form.

Do you have a preference for which to make canonical?

Dan