Pull in r181286 from upstream llvm trunk:

  LoopVectorize: getConsecutiveVector must respect signed arithmetic

  We were passing an i32 to ConstantInt::get where an i64 was needed and we must
  also pass the sign if we pass negatives numbers. The start index passed to
  getConsecutiveVector must also be signed.

  Should fix PR15882.

This should fix Firefox crashes some people have been reporting, when it
is compiled with -O3.

1 files changed, 6 insertions, 5 deletions

diff --git a/contrib/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/contrib/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 8d51df4..9d65a5e 100644
--- a/contrib/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/contrib/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -214,7 +214,7 @@ private:
   /// This function adds 0, 1, 2 ... to each vector element, starting at zero.
   /// If Negate is set then negative numbers are added e.g. (0, -1, -2, ...).
   /// The sequence starts at StartIndex.
-  Value *getConsecutiveVector(Value* Val, unsigned StartIdx, bool Negate);
+  Value *getConsecutiveVector(Value* Val, int StartIdx, bool Negate);
 
   /// When we go over instructions in the basic block we rely on previous
   /// values within the current basic block or on loop invariant values.
@@ -771,7 +771,7 @@ Value *InnerLoopVectorizer::getBroadcastInstrs(Value *V) {
   return Shuf;
 }
 
-Value *InnerLoopVectorizer::getConsecutiveVector(Value* Val, unsigned StartIdx,
+Value *InnerLoopVectorizer::getConsecutiveVector(Value* Val, int StartIdx,
                                                  bool Negate) {
   assert(Val->getType()->isVectorTy() && "Must be a vector");
   assert(Val->getType()->getScalarType()->isIntegerTy() &&
@@ -784,8 +784,8 @@ Value *InnerLoopVectorizer::getConsecutiveVector(Value* Val, unsigned StartIdx,
 
   // Create a vector of consecutive numbers from zero to VF.
   for (int i = 0; i < VLen; ++i) {
-    int Idx = Negate ? (-i): i;
-    Indices.push_back(ConstantInt::get(ITy, StartIdx + Idx));
+    int64_t Idx = Negate ? (-i) : i;
+    Indices.push_back(ConstantInt::get(ITy, StartIdx + Idx, Negate));
   }
 
   // Add the consecutive indices to the vector value.
@@ -1928,7 +1928,8 @@ InnerLoopVectorizer::vectorizeBlockInLoop(LoopVectorizationLegality *Legal,
           // After broadcasting the induction variable we need to make the
           // vector consecutive by adding  ... -3, -2, -1, 0.
           for (unsigned part = 0; part < UF; ++part)
-            Entry[part] = getConsecutiveVector(Broadcasted, -VF * part, true);
+            Entry[part] = getConsecutiveVector(Broadcasted, -(int)VF * part,
+                                               true);
           continue;
         }