[PATCH] D17859: [InstCombine] convert 'isPositive' and 'isNegative' vector comparisons to shifts (PR26701, PR26819)
Mehdi AMINI via llvm-commits
llvm-commits at lists.llvm.org
Thu Mar 24 16:26:10 PDT 2016
joker.eph added inline comments.
Comment at: lib/Transforms/InstCombine/InstCombineCasts.cpp:985
@@ +984,3 @@
+ // because vector ISAs may not have a full range of comparison
+ // operators. This cmp+sext transform, however, will simplify the IR, so
+ // we always do it.
I usually see canonicalization as something that is target independent, and then after optimization the lowering can adjust toward something that the target will "like" (ultimately the SDAG legalizer is doing this). Any comment?
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