Create parallel code in a separate block

  This commit basically reverts r246427 but still solves the issue
  tackled by that commit. Instead of emitting initialization code in the
  beginning of the start block we now generate parallel code in its own
  block and thereby guarantee separation. This is necessary as we cannot
  generate code for hoisted loads prior to the start block but it still
  needs to be placed prior to everything else.

llvm-svn: 248674

1 files changed, 8 insertions, 0 deletions

diff --git a/polly/lib/CodeGen/IslNodeBuilder.cpp b/polly/lib/CodeGen/IslNodeBuilder.cpp
index 85c92402dcd..1574e6167f0 100644
--- a/polly/lib/CodeGen/IslNodeBuilder.cpp
+++ b/polly/lib/CodeGen/IslNodeBuilder.cpp
@@ -534,6 +534,14 @@ void IslNodeBuilder::createForParallel(__isl_take isl_ast_node *For) {
   Value *IV;
   CmpInst::Predicate Predicate;
 
+  // The preamble of parallel code interacts different than normal code with
+  // e.g., scalar initialization. Therefore, we ensure the parallel code is
+  // separated from the last basic block.
+  BasicBlock *ParBB =
+      SplitBlock(Builder.GetInsertBlock(), Builder.GetInsertPoint(), &DT, &LI);
+  ParBB->setName("polly.parallel.for");
+  Builder.SetInsertPoint(ParBB->begin());
+
   Body = isl_ast_node_for_get_body(For);
   Init = isl_ast_node_for_get_init(For);
   Inc = isl_ast_node_for_get_inc(For);