[InstCombine] Refactor getFlippedStrictnessPredicateAndConstant() out of canonicalizeCmpWithConstant(), NFCI

I'd like to use it elsewhere, hopefully without reinventing the wheel.
No functional change intended so far.

llvm-svn: 368820

1 files changed, 3 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
index 957fcd1b9f5..f8225b82ed1 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
+++ b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
@@ -113,6 +113,9 @@ static inline bool isCanonicalPredicate(CmpInst::Predicate Pred) {
   }
 }
 
+llvm::Optional<std::pair<CmpInst::Predicate, Constant *>>
+getFlippedStrictnessPredicateAndConstant(CmpInst::Predicate Pred, Constant *C);
+
 /// Return the source operand of a potentially bitcasted value while optionally
 /// checking if it has one use. If there is no bitcast or the one use check is
 /// not met, return the input value itself.