Revert "[InstCombine] Delay foldICmpUsingKnownBits until simple transforms are done"

llvm-svn: 336410

1 files changed, 3 insertions, 7 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 41e4124d686..d52ea2cf6eb 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -4485,6 +4485,9 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) {
   if (Instruction *Res = foldICmpWithConstant(I))
     return Res;
 
+  if (Instruction *Res = foldICmpUsingKnownBits(I))
+    return Res;
+
   // Test if the ICmpInst instruction is used exclusively by a select as
   // part of a minimum or maximum operation. If so, refrain from doing
   // any other folding. This helps out other analyses which understand
@@ -4703,13 +4706,6 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) {
     if (match(Op1, m_Add(m_Value(X), m_ConstantInt(Cst))) && Op0 == X)
       return foldICmpAddOpConst(X, Cst, I.getSwappedPredicate());
   }
-
-  // This may be expensive in compile-time, and transforms based on known bits
-  // can make further analysis more difficult, so we use it as the last resort
-  // if we cannot do anything better.
-  if (Instruction *Res = foldICmpUsingKnownBits(I))
-    return Res;
-
   return Changed ? &I : nullptr;
 }