[PATCH] D40130: [InstSimplify] fold and/or of fcmp ord/uno when operand is known nnan

[Sanjay Patel via Phabricator via llvm-commits]

spatel created this revision.
Herald added a subscriber: mcrosier.

The 'ord' and 'uno' predicates have a logic operation for NAN built into their definitions:

  FCMP_ORD   =  7,  ///< 0 1 1 1    True if ordered (no nans)
  FCMP_UNO   =  8,  ///< 1 0 0 0    True if unordered: isnan(X) | isnan(Y)

So we can simplify patterns like this:

  (fcmp ord NNAN, X) && (fcmp ord X, Y) --> fcmp ord X, Y
  (fcmp uno NNAN, X) || (fcmp uno X, Y) --> fcmp uno X, Y


https://reviews.llvm.org/D40130

Files:
  lib/Analysis/InstructionSimplify.cpp
  test/Transforms/InstSimplify/logic-of-fcmps.ll

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