[llvm] r340939 - [InstCombine] Replace two calls to getNumUses() with !hasNUsesOrMore

[Craig Topper via llvm-commits]

Author: ctopper
Date: Wed Aug 29 10:09:21 2018
New Revision: 340939

URL: http://llvm.org/viewvc/llvm-project?rev=340939&view=rev
Log:
[InstCombine] Replace two calls to getNumUses() with !hasNUsesOrMore

We were calling getNumUses to check for 1 or 2 uses. But getNumUses is linear in the number of uses. We can instead use !hasNUsesOrMore(3) which will stop the linear scan as soon as it determines there are at least 3 uses even if there are more.

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp?rev=340939&r1=340938&r2=340939&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp Wed Aug 29 10:09:21 2018
@@ -1822,7 +1822,7 @@ Instruction *InstCombiner::visitSelectIn
       // MIN(~a, ~b) -> ~MAX(a, b)
       Value *A, *B;
       if (match(LHS, m_Not(m_Value(A))) && match(RHS, m_Not(m_Value(B))) &&
-          (LHS->getNumUses() <= 2 || RHS->getNumUses() <= 2)) {
+          (!LHS->hasNUsesOrMore(3) || !RHS->hasNUsesOrMore(3))) {
         CmpInst::Predicate InvertedPred = getInverseMinMaxPred(SPF);
         Value *InvertedCmp = Builder.CreateICmp(InvertedPred, A, B);
         Value *NewSel = Builder.CreateSelect(InvertedCmp, A, B);