[llvm] [CodeGen] Add OffloadBlockUniformityAnalysis for offload PGO (PR #178417)

[Matt Arsenault via llvm-commits]

================
@@ -0,0 +1,121 @@
+//===- BlockUniformityProfile.cpp - Block uniformity from PGO -----------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/BlockUniformityProfile.h"
+#include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Metadata.h"
+#include "llvm/Support/raw_ostream.h"
+#include <optional>
+
+using namespace llvm;
+
+static std::optional<bool> getIRBlockUniformity(const BasicBlock &BB) {
+  const Instruction *TI = BB.getTerminator();
+  if (!TI)
----------------
arsenm wrote:

Shouldn't need to tolerate ill-formed IR 

https://github.com/llvm/llvm-project/pull/178417