Merge "Update prebuilt Clang to r353983." into p9.0HEADp9.0-backupp9.0

1 files changed, 36 insertions, 0 deletions

diff --git a/clang-r353983/include/llvm/CodeGen/UnreachableBlockElim.h b/clang-r353983/include/llvm/CodeGen/UnreachableBlockElim.h
new file mode 100644
index 00000000..d52d7c3c
--- /dev/null
+++ b/clang-r353983/include/llvm/CodeGen/UnreachableBlockElim.h
@@ -0,0 +1,36 @@
+//===-- UnreachableBlockElim.h - Remove unreachable blocks for codegen --===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass is an extremely simple version of the SimplifyCFG pass.  Its sole
+// job is to delete LLVM basic blocks that are not reachable from the entry
+// node.  To do this, it performs a simple depth first traversal of the CFG,
+// then deletes any unvisited nodes.
+//
+// Note that this pass is really a hack.  In particular, the instruction
+// selectors for various targets should just not generate code for unreachable
+// blocks.  Until LLVM has a more systematic way of defining instruction
+// selectors, however, we cannot really expect them to handle additional
+// complexity.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_CODEGEN_UNREACHABLEBLOCKELIM_H
+#define LLVM_LIB_CODEGEN_UNREACHABLEBLOCKELIM_H
+
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+
+class UnreachableBlockElimPass
+    : public PassInfoMixin<UnreachableBlockElimPass> {
+public:
+  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
+};
+} // end namespace llvm
+
+#endif // LLVM_LIB_CODEGEN_UNREACHABLEBLOCKELIM_H