RunTimeDebugBuilder: Allocate memory _after_ knowing how much is needed

This fixes a memory corruption issue, where we accessed more memory than
actually allocated.

llvm-svn: 252197

1 files changed, 7 insertions, 7 deletions

diff --git a/polly/lib/CodeGen/RuntimeDebugBuilder.cpp b/polly/lib/CodeGen/RuntimeDebugBuilder.cpp
index dd2432ad31d..29f113dbd0c 100644
--- a/polly/lib/CodeGen/RuntimeDebugBuilder.cpp
+++ b/polly/lib/CodeGen/RuntimeDebugBuilder.cpp
@@ -163,20 +163,20 @@ void RuntimeDebugBuilder::createGPUPrinterT(PollyIRBuilder &Builder,
                                             ArrayRef<Value *> Values) {
   std::string str;
 
-  // Allocate print buffer (assuming 2*32 bit per element)
-  auto T = ArrayType::get(Builder.getInt32Ty(), Values.size() * 2);
-  Value *Data = new AllocaInst(
-      T, "polly.vprint.buffer",
-      Builder.GetInsertBlock()->getParent()->getEntryBlock().begin());
-
   auto *Zero = Builder.getInt64(0);
-  auto *DataPtr = Builder.CreateGEP(Data, {Zero, Zero});
 
   auto ToPrint = getGPUThreadIdentifiers(Builder);
 
   ToPrint.push_back(Builder.CreateGlobalStringPtr("\n  ", "", 4));
   ToPrint.insert(ToPrint.end(), Values.begin(), Values.end());
 
+  // Allocate print buffer (assuming 2*32 bit per element)
+  auto T = ArrayType::get(Builder.getInt32Ty(), ToPrint.size() * 2);
+  Value *Data = new AllocaInst(
+      T, "polly.vprint.buffer",
+      Builder.GetInsertBlock()->getParent()->getEntryBlock().begin());
+  auto *DataPtr = Builder.CreateGEP(Data, {Zero, Zero});
+
   int Offset = 0;
   for (auto Val : ToPrint) {
     auto Ptr = Builder.CreateGEP(DataPtr, Builder.getInt64(Offset));