1 files changed, 37 insertions, 11 deletions

diff --git a/lib/Transforms/InstCombine/InstCombineSelect.cpp b/lib/Transforms/InstCombine/InstCombineSelect.cpp
index 97abc76..61a433a 100644
--- a/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -214,7 +214,7 @@ Instruction *InstCombiner::FoldSelectIntoOp(SelectInst &SI, Value *TrueVal,
         unsigned OpToFold = 0;
         if ((SFO & 1) && FalseVal == TVI->getOperand(0)) {
           OpToFold = 1;
-        } else  if ((SFO & 2) && FalseVal == TVI->getOperand(1)) {
+        } else if ((SFO & 2) && FalseVal == TVI->getOperand(1)) {
           OpToFold = 2;
         }
 
@@ -227,9 +227,16 @@ Instruction *InstCombiner::FoldSelectIntoOp(SelectInst &SI, Value *TrueVal,
             Instruction *NewSel = SelectInst::Create(SI.getCondition(), OOp, C);
             InsertNewInstBefore(NewSel, SI);
             NewSel->takeName(TVI);
-            if (BinaryOperator *BO = dyn_cast<BinaryOperator>(TVI))
-              return BinaryOperator::Create(BO->getOpcode(), FalseVal, NewSel);
-            llvm_unreachable("Unknown instruction!!");
+            BinaryOperator *TVI_BO = cast<BinaryOperator>(TVI);
+            BinaryOperator *BO = BinaryOperator::Create(TVI_BO->getOpcode(),
+                                                        FalseVal, NewSel);
+            if (isa<PossiblyExactOperator>(BO))
+              BO->setIsExact(TVI_BO->isExact());
+            if (isa<OverflowingBinaryOperator>(BO)) {
+              BO->setHasNoUnsignedWrap(TVI_BO->hasNoUnsignedWrap());
+              BO->setHasNoSignedWrap(TVI_BO->hasNoSignedWrap());
+            }
+            return BO;
           }
         }
       }
@@ -243,7 +250,7 @@ Instruction *InstCombiner::FoldSelectIntoOp(SelectInst &SI, Value *TrueVal,
         unsigned OpToFold = 0;
         if ((SFO & 1) && TrueVal == FVI->getOperand(0)) {
           OpToFold = 1;
-        } else  if ((SFO & 2) && TrueVal == FVI->getOperand(1)) {
+        } else if ((SFO & 2) && TrueVal == FVI->getOperand(1)) {
           OpToFold = 2;
         }
 
@@ -256,9 +263,16 @@ Instruction *InstCombiner::FoldSelectIntoOp(SelectInst &SI, Value *TrueVal,
             Instruction *NewSel = SelectInst::Create(SI.getCondition(), C, OOp);
             InsertNewInstBefore(NewSel, SI);
             NewSel->takeName(FVI);
-            if (BinaryOperator *BO = dyn_cast<BinaryOperator>(FVI))
-              return BinaryOperator::Create(BO->getOpcode(), TrueVal, NewSel);
-            llvm_unreachable("Unknown instruction!!");
+            BinaryOperator *FVI_BO = cast<BinaryOperator>(FVI);
+            BinaryOperator *BO = BinaryOperator::Create(FVI_BO->getOpcode(),
+                                                        TrueVal, NewSel);
+            if (isa<PossiblyExactOperator>(BO))
+              BO->setIsExact(FVI_BO->isExact());
+            if (isa<OverflowingBinaryOperator>(BO)) {
+              BO->setHasNoUnsignedWrap(FVI_BO->hasNoUnsignedWrap());
+              BO->setHasNoSignedWrap(FVI_BO->hasNoSignedWrap());
+            }
+            return BO;
           }
         }
       }
@@ -424,6 +438,19 @@ Instruction *InstCombiner::visitSelectInstWithICmp(SelectInst &SI,
       return ReplaceInstUsesWith(SI, TrueVal);
     /// NOTE: if we wanted to, this is where to detect integer MIN/MAX
   }
+
+  if (isa<Constant>(CmpRHS)) {
+    if (CmpLHS == TrueVal && Pred == ICmpInst::ICMP_EQ) {
+      // Transform (X == C) ? X : Y -> (X == C) ? C : Y
+      SI.setOperand(1, CmpRHS);
+      Changed = true;
+    } else if (CmpLHS == FalseVal && Pred == ICmpInst::ICMP_NE) {
+      // Transform (X != C) ? Y : X -> (X != C) ? Y : C
+      SI.setOperand(2, CmpRHS);
+      Changed = true;
+    }
+  }
+
   return Changed ? &SI : 0;
 }
 
@@ -503,9 +530,8 @@ static Value *foldSelectICmpAnd(const SelectInst &SI, ConstantInt *TrueVal,
   if (!IC || !IC->isEquality())
     return 0;
 
-  if (ConstantInt *C = dyn_cast<ConstantInt>(IC->getOperand(1)))
-    if (!C->isZero())
-      return 0;
+  if (!match(IC->getOperand(1), m_Zero()))
+    return 0;
 
   ConstantInt *AndRHS;
   Value *LHS = IC->getOperand(0);