vendor/llvm/llvm-trunk-r375505vendor/llvm

1 files changed, 43 insertions, 0 deletions

diff --git a/include/llvm/Transforms/Utils/MisExpect.h b/include/llvm/Transforms/Utils/MisExpect.h
new file mode 100644
index 000000000000..1dbe8cb95936
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+++ b/include/llvm/Transforms/Utils/MisExpect.h
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+//===--- MisExpect.h - Check the use of llvm.expect with PGO data ---------===//
+//
+// 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 contains code to emit warnings for potentially incorrect usage of the
+// llvm.expect intrinsic. This utility extracts the threshold values from
+// metadata associated with the instrumented Branch or Switch instruction. The
+// threshold values are then used to determine if a warning should be emmited.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/LLVMContext.h"
+
+namespace llvm {
+namespace misexpect {
+
+/// verifyMisExpect - compares PGO counters to the thresholds used for
+/// llvm.expect and warns if the PGO counters are outside of the expected
+/// range.
+/// \param I The Instruction being checked
+/// \param Weights A vector of profile weights for each target block
+/// \param Ctx The current LLVM context
+void verifyMisExpect(llvm::Instruction *I,
+                     const llvm::SmallVector<uint32_t, 4> &Weights,
+                     llvm::LLVMContext &Ctx);
+
+/// checkClangInstrumentation - verify if llvm.expect matches PGO profile
+/// This function checks the frontend instrumentation in the backend when
+/// lowering llvm.expect intrinsics. It checks for existing metadata, and
+/// then validates the use of llvm.expect against the assigned branch weights.
+//
+/// \param I the Instruction being checked
+void checkFrontendInstrumentation(Instruction &I);
+
+} // namespace misexpect
+} // namespace llvm