Merge XXXGenRegisterDesc.inc XXXGenRegisterNames.inc XXXGenRegisterInfo.h.inc

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

diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp
index 77ad82895853f0f999efd5d355112fdcfea5fab7..601d9b42f31454c4157c0344a75b6342bde41730 100644 (file)
--- a/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -71,6 +71,11 @@ Instruction *InstCombiner::PromoteCastOfAllocation(BitCastInst &CI,
   // This requires TargetData to get the alloca alignment and size information.
   if (!TD) return 0;
 
+  // Insist that the amount-to-allocate not overflow.
+  OverflowingBinaryOperator *OBI =
+    dyn_cast<OverflowingBinaryOperator>(AI.getOperand(0));
+  if (OBI && !(OBI->hasNoSignedWrap() || OBI->hasNoUnsignedWrap())) return 0;
+
   const PointerType *PTy = cast<PointerType>(CI.getType());
   
   BuilderTy AllocaBuilder(*Builder);
@@ -133,7 +138,7 @@ Instruction *InstCombiner::PromoteCastOfAllocation(BitCastInst &CI,
     // New is the allocation instruction, pointer typed. AI is the original
     // allocation instruction, also pointer typed. Thus, cast to use is BitCast.
     Value *NewCast = AllocaBuilder.CreateBitCast(New, AI.getType(), "tmpcast");
-    AI.replaceAllUsesWith(NewCast);
+    ReplaceInstUsesWith(AI, NewCast);
   }
   return ReplaceInstUsesWith(CI, New);
 }
@@ -211,7 +216,7 @@ Value *InstCombiner::EvaluateInDifferentType(Value *V, const Type *Ty,
   }
   
   Res->takeName(I);
-  return InsertNewInstBefore(Res, *I);
+  return InsertNewInstWith(Res, *I);
 }
 
 
@@ -882,13 +887,9 @@ Instruction *InstCombiner::transformSExtICmp(ICmpInst *ICI, Instruction &CI) {
   Value *Op0 = ICI->getOperand(0), *Op1 = ICI->getOperand(1);
   ICmpInst::Predicate Pred = ICI->getPredicate();
 
-  // Transforming icmps with more than one use is not profitable.
-  if (!ICI->hasOneUse())
-    return 0;
-
   if (ConstantInt *Op1C = dyn_cast<ConstantInt>(Op1)) {
-    // (x <s 0) ? -1 : 0 -> ashr x, 31   -> all ones if signed
-    // (x >s -1) ? -1 : 0 -> ashr x, 31  -> all ones if not signed
+    // (x <s  0) ? -1 : 0 -> ashr x, 31        -> all ones if negative
+    // (x >s -1) ? -1 : 0 -> not (ashr x, 31)  -> all ones if positive
     if ((Pred == ICmpInst::ICMP_SLT && Op1C->isZero()) ||
         (Pred == ICmpInst::ICMP_SGT && Op1C->isAllOnesValue())) {
 
@@ -906,7 +907,8 @@ Instruction *InstCombiner::transformSExtICmp(ICmpInst *ICI, Instruction &CI) {
     // If we know that only one bit of the LHS of the icmp can be set and we
     // have an equality comparison with zero or a power of 2, we can transform
     // the icmp and sext into bitwise/integer operations.
-    if (ICI->isEquality() && (Op1C->isZero() || Op1C->getValue().isPowerOf2())){
+    if (ICI->hasOneUse() &&
+        ICI->isEquality() && (Op1C->isZero() || Op1C->getValue().isPowerOf2())){
       unsigned BitWidth = Op1C->getType()->getBitWidth();
       APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
       APInt TypeMask(APInt::getAllOnesValue(BitWidth));
@@ -916,6 +918,14 @@ Instruction *InstCombiner::transformSExtICmp(ICmpInst *ICI, Instruction &CI) {
       if (KnownZeroMask.isPowerOf2()) {
         Value *In = ICI->getOperand(0);
 
+        // If the icmp tests for a known zero bit we can constant fold it.
+        if (!Op1C->isZero() && Op1C->getValue() != KnownZeroMask) {
+          Value *V = Pred == ICmpInst::ICMP_NE ?
+                       ConstantInt::getAllOnesValue(CI.getType()) :
+                       ConstantInt::getNullValue(CI.getType());
+          return ReplaceInstUsesWith(CI, V);
+        }
+
         if (!Op1C->isZero() == (Pred == ICmpInst::ICMP_NE)) {
           // sext ((x & 2^n) == 0)   -> (x >> n) - 1
           // sext ((x & 2^n) != 2^n) -> (x >> n) - 1
@@ -932,7 +942,7 @@ Instruction *InstCombiner::transformSExtICmp(ICmpInst *ICI, Instruction &CI) {
                                   "sext");
         } else {
           // sext ((x & 2^n) != 0)   -> (x << bitwidth-n) a>> bitwidth-1
-          // sext ((x & 2^n) != 2^n) -> (x << bitwidth-n) a>> bitwidth-1
+          // sext ((x & 2^n) == 2^n) -> (x << bitwidth-n) a>> bitwidth-1
           unsigned ShiftAmt = KnownZeroMask.countLeadingZeros();
           // Perform a left shift to place the desired bit in the MSB.
           if (ShiftAmt)
@@ -1223,7 +1233,7 @@ Instruction *InstCombiner::visitFPTrunc(FPTruncInst &CI) {
       
       
       // Remove the old Call.  With -fmath-errno, it won't get marked readnone.
-      Call->replaceAllUsesWith(UndefValue::get(Call->getType()));
+      ReplaceInstUsesWith(*Call, UndefValue::get(Call->getType()));
       EraseInstFromFunction(*Call);
       return ret;
     }
@@ -1679,8 +1689,7 @@ Instruction *InstCombiner::visitBitCast(BitCastInst &CI) {
     // If we found a path from the src to dest, create the getelementptr now.
     if (SrcElTy == DstElTy) {
       SmallVector<Value*, 8> Idxs(NumZeros+1, ZeroUInt);
-      return GetElementPtrInst::CreateInBounds(Src, Idxs.begin(), Idxs.end(),"",
-                                               ((Instruction*)NULL));
+      return GetElementPtrInst::CreateInBounds(Src, Idxs.begin(), Idxs.end());
     }
   }