| //===--- 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 |
