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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181286 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 5 deletions

diff --git a/lib/Transforms/Vectorize/LoopVectorize.cpp b/lib/Transforms/Vectorize/LoopVectorize.cpp
index 491e9cc..ad4a6c7 100644
--- a/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -216,7 +216,7 @@ 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.
@@ -829,7 +829,7 @@ 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() &&
@@ -842,8 +842,8 @@ 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.
@@ -2072,7 +2072,8 @@ 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;
         }