[llvm-dev] Any users of -liv-reduce?

Sanjoy Das via llvm-dev llvm-dev at lists.llvm.org
Sun Apr 10 16:08:21 PDT 2016

Are people actively using the -liv-reduce option?

See IndVarSimplify.cpp:

static cl::opt<bool> ReduceLiveIVs("liv-reduce", cl::Hidden,
   cl::desc("Reduce live induction variables."));

-liv-reduce is an off-by-default internal option that splits
<op>.with.overflow intrinsics into arithmetic and explicit overflow
checks, so that SCEV can widen and optimize these.  After two recent
changes [0], "-liv-reduce" should no longer be necessary for SCEV to
recognize and optimize overflow intrinsics, so I'd prefer to remove it
unless there are people who actively depend on it.

[0]: http://reviews.llvm.org/rL265912 and http://reviews.llvm.org/rL265913

-- Sanjoy

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