1 files changed, 24 insertions, 15 deletions

diff --git a/lib/Transforms/InstCombine/InstCombineSelect.cpp b/lib/Transforms/InstCombine/InstCombineSelect.cpp
index 91e60a4..e727b2c 100644
--- a/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -184,7 +184,6 @@ Instruction *InstCombiner::FoldSelectOpOp(SelectInst &SI, Instruction *TI,
       return BinaryOperator::Create(BO->getOpcode(), NewSI, MatchOp);
   }
   llvm_unreachable("Shouldn't get here");
-  return 0;
 }
 
 static bool isSelect01(Constant *C1, Constant *C2) {
@@ -282,7 +281,8 @@ Instruction *InstCombiner::FoldSelectIntoOp(SelectInst &SI, Value *TrueVal,
 /// SimplifyWithOpReplaced - See if V simplifies when its operand Op is
 /// replaced with RepOp.
 static Value *SimplifyWithOpReplaced(Value *V, Value *Op, Value *RepOp,
-                                     const TargetData *TD) {
+                                     const TargetData *TD,
+                                     const TargetLibraryInfo *TLI) {
   // Trivial replacement.
   if (V == Op)
     return RepOp;
@@ -294,17 +294,19 @@ static Value *SimplifyWithOpReplaced(Value *V, Value *Op, Value *RepOp,
   // If this is a binary operator, try to simplify it with the replaced op.
   if (BinaryOperator *B = dyn_cast<BinaryOperator>(I)) {
     if (B->getOperand(0) == Op)
-      return SimplifyBinOp(B->getOpcode(), RepOp, B->getOperand(1), TD);
+      return SimplifyBinOp(B->getOpcode(), RepOp, B->getOperand(1), TD, TLI);
     if (B->getOperand(1) == Op)
-      return SimplifyBinOp(B->getOpcode(), B->getOperand(0), RepOp, TD);
+      return SimplifyBinOp(B->getOpcode(), B->getOperand(0), RepOp, TD, TLI);
   }
 
   // Same for CmpInsts.
   if (CmpInst *C = dyn_cast<CmpInst>(I)) {
     if (C->getOperand(0) == Op)
-      return SimplifyCmpInst(C->getPredicate(), RepOp, C->getOperand(1), TD);
+      return SimplifyCmpInst(C->getPredicate(), RepOp, C->getOperand(1), TD,
+                             TLI);
     if (C->getOperand(1) == Op)
-      return SimplifyCmpInst(C->getPredicate(), C->getOperand(0), RepOp, TD);
+      return SimplifyCmpInst(C->getPredicate(), C->getOperand(0), RepOp, TD,
+                             TLI);
   }
 
   // TODO: We could hand off more cases to instsimplify here.
@@ -330,7 +332,7 @@ static Value *SimplifyWithOpReplaced(Value *V, Value *Op, Value *RepOp,
           return ConstantFoldLoadFromConstPtr(ConstOps[0], TD);
 
       return ConstantFoldInstOperands(I->getOpcode(), I->getType(),
-                                      ConstOps, TD);
+                                      ConstOps, TD, TLI);
     }
   }
 
@@ -479,18 +481,18 @@ Instruction *InstCombiner::visitSelectInstWithICmp(SelectInst &SI,
   // arms of the select. See if substituting this value into the arm and
   // simplifying the result yields the same value as the other arm.
   if (Pred == ICmpInst::ICMP_EQ) {
-    if (SimplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, TD) == TrueVal ||
-        SimplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, TD) == TrueVal)
+    if (SimplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, TD, TLI) == TrueVal ||
+        SimplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, TD, TLI) == TrueVal)
       return ReplaceInstUsesWith(SI, FalseVal);
-    if (SimplifyWithOpReplaced(TrueVal, CmpLHS, CmpRHS, TD) == FalseVal ||
-        SimplifyWithOpReplaced(TrueVal, CmpRHS, CmpLHS, TD) == FalseVal)
+    if (SimplifyWithOpReplaced(TrueVal, CmpLHS, CmpRHS, TD, TLI) == FalseVal ||
+        SimplifyWithOpReplaced(TrueVal, CmpRHS, CmpLHS, TD, TLI) == FalseVal)
       return ReplaceInstUsesWith(SI, FalseVal);
   } else if (Pred == ICmpInst::ICMP_NE) {
-    if (SimplifyWithOpReplaced(TrueVal, CmpLHS, CmpRHS, TD) == FalseVal ||
-        SimplifyWithOpReplaced(TrueVal, CmpRHS, CmpLHS, TD) == FalseVal)
+    if (SimplifyWithOpReplaced(TrueVal, CmpLHS, CmpRHS, TD, TLI) == FalseVal ||
+        SimplifyWithOpReplaced(TrueVal, CmpRHS, CmpLHS, TD, TLI) == FalseVal)
       return ReplaceInstUsesWith(SI, TrueVal);
-    if (SimplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, TD) == TrueVal ||
-        SimplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, TD) == TrueVal)
+    if (SimplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, TD, TLI) == TrueVal ||
+        SimplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, TD, TLI) == TrueVal)
       return ReplaceInstUsesWith(SI, TrueVal);
   }
 
@@ -679,6 +681,13 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) {
       return BinaryOperator::CreateOr(CondVal, FalseVal);
     else if (CondVal == FalseVal)
       return BinaryOperator::CreateAnd(CondVal, TrueVal);
+
+    // select a, ~a, b -> (~a)&b
+    // select a, b, ~a -> (~a)|b
+    if (match(TrueVal, m_Not(m_Specific(CondVal))))
+      return BinaryOperator::CreateAnd(TrueVal, FalseVal);
+    else if (match(FalseVal, m_Not(m_Specific(CondVal))))
+      return BinaryOperator::CreateOr(TrueVal, FalseVal);
   }
 
   // Selecting between two integer constants?