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[IndVars, RLEV] Support rewriting exit values in loops without known exits…

Description

[IndVars, RLEV] Support rewriting exit values in loops without known exits (prep work)

This is a prepatory patch for future work on support exit value rewriting in loops with a mixture of computable and non-computable exit counts. The intention is to be "mostly NFC" - i.e. not enable any interesting new transforms - but in practice, there are some small output changes.

The test differences are caused by cases wherewhere getSCEVAtScope can simplify a single entry phi without needing any knowledge of the loop.

Details

Committed
reamesJul 31 2019, 2:15 PM
Parents
rL367484: [NFC] allow creating error strings from a Twine
Branches
Unknown
Tags
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Event Timeline

thakis added inline comments.
/llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp
2784

This causes

/Users/buildslave/as-bldslv9_new/lld-x86_64-darwin13/llvm.src/lib/Transforms/Scalar/IndVarSimplify.cpp:2761:15: error: unused variable 'BackedgeTakenCount' [-Werror,-Wunused-variable]
  const SCEV *BackedgeTakenCount = SE->getBackedgeTakenCount(L);
              ^
reames marked an inline comment as done.Jul 31 2019, 6:16 PM
reames added inline comments.
/llvm/trunk/lib/Transforms/Scalar/IndVarSimplify.cpp
2784

Fixed in revision 367499.

Is there a reason I'm not getting direct notice from the buildbots on these?