Vendor import of llvm trunk r135360:

http://llvm.org/svn/llvm-project/llvm/trunk@135360

1 files changed, 10 insertions, 1 deletions

diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp
index 199902a..82c734e 100644
--- a/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -30,6 +30,14 @@ static Value *DecomposeSimpleLinearExpr(Value *Val, unsigned &Scale,
   }
   
   if (BinaryOperator *I = dyn_cast<BinaryOperator>(Val)) {
+    // Cannot look past anything that might overflow.
+    OverflowingBinaryOperator *OBI = dyn_cast<OverflowingBinaryOperator>(Val);
+    if (OBI && !OBI->hasNoUnsignedWrap()) {
+      Scale = 1;
+      Offset = 0;
+      return Val;
+    }
+
     if (ConstantInt *RHS = dyn_cast<ConstantInt>(I->getOperand(1))) {
       if (I->getOpcode() == Instruction::Shl) {
         // This is a value scaled by '1 << the shift amt'.
@@ -1208,7 +1216,8 @@ Instruction *InstCombiner::visitFPTrunc(FPTruncInst &CI) {
   CallInst *Call = dyn_cast<CallInst>(CI.getOperand(0));
   if (Call && Call->getCalledFunction() &&
       Call->getCalledFunction()->getName() == "sqrt" &&
-      Call->getNumArgOperands() == 1) {
+      Call->getNumArgOperands() == 1 &&
+      Call->hasOneUse()) {
     CastInst *Arg = dyn_cast<CastInst>(Call->getArgOperand(0));
     if (Arg && Arg->getOpcode() == Instruction::FPExt &&
         CI.getType()->isFloatTy() &&