[PATCH] D17859: [InstCombine] convert 'isPositive' and 'isNegative' vector comparisons to shifts (PR26701, PR26819)

[Sanjay Patel via llvm-commits]

spatel added reviewers: escha, MatzeB.
spatel added a comment.

Ping * 6.

For reference, some other questions about where we draw the 'canonical IR' line:
http://lists.llvm.org/pipermail/llvm-dev/2016-April/098154.html
https://llvm.org/bugs/show_bug.cgi?id=27343
https://llvm.org/bugs/show_bug.cgi?id=24766#c2

We try to maintain our target-independent idealism in IR, particularly in InstCombine, but we do make concessions for practical target constraints.

For this (really minor!) case, I think the potentially limited range of vector functionality is reason not to try hard to canonicalize vector comparisons in the same way as integer comparisons.


http://reviews.llvm.org/D17859