Don't forget to transfer implicit uses of return instruction.

[oota-llvm.git] / lib / Transforms / InstCombine / InstCombineSelect.cpp

diff --git a/lib/Transforms/InstCombine/InstCombineSelect.cpp b/lib/Transforms/InstCombine/InstCombineSelect.cpp
index bd7f40d8acaf1da3989eeaa11e96f6d1c6e3cf44..f1ea8ead1f97cc5d0b1f2c5f1e0d124a1efd4f8e 100644 (file)
--- a/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -13,6 +13,7 @@
 
 #include "InstCombine.h"
 #include "llvm/Support/PatternMatch.h"
+#include "llvm/Analysis/ConstantFolding.h"
 #include "llvm/Analysis/InstructionSimplify.h"
 using namespace llvm;
 using namespace PatternMatch;
@@ -281,7 +282,8 @@ 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;
@@ -293,17 +295,19 @@ 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.
@@ -323,9 +327,14 @@ static Value *SimplifyWithOpReplaced(Value *V, Value *Op, Value *RepOp,
     }
 
     // All operands were constants, fold it.
-    if (ConstOps.size() == I->getNumOperands())
+    if (ConstOps.size() == I->getNumOperands()) {
+      if (LoadInst *LI = dyn_cast<LoadInst>(I))
+        if (!LI->isVolatile())
+          return ConstantFoldLoadFromConstPtr(ConstOps[0], TD);
+
       return ConstantFoldInstOperands(I->getOpcode(), I->getType(),
-                                      ConstOps, TD);
+                                      ConstOps, TD, TLI);
+    }
   }
 
   return 0;
@@ -473,12 +482,18 @@ 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, 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, TLI) == TrueVal ||
+        SimplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, TD, TLI) == TrueVal)
       return ReplaceInstUsesWith(SI, TrueVal);
   }
 
@@ -667,6 +682,13 @@ 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?