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| Rev | Author | Line No. | Line |
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| 14 | pmbaty | 1 | //===--- MisExpect.h - Check the use of llvm.expect with PGO data ---------===// |
| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | // This contains code to emit diagnostic messages for potentially incorrect |
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| 10 | // usage of the llvm.expect intrinsic. This utility extracts the threshold |
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| 11 | // values from metadata associated with the instrumented Branch or Switch |
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| 12 | // instruction. The threshold values are then used to determine if a diagnostic |
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| 13 | // should be emitted. |
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| 14 | // |
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| 15 | //===----------------------------------------------------------------------===// |
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| 16 | |||
| 17 | #ifndef LLVM_TRANSFORMS_UTILS_MISEXPECT_H |
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| 18 | #define LLVM_TRANSFORMS_UTILS_MISEXPECT_H |
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| 19 | |||
| 20 | #include "llvm/ADT/SmallVector.h" |
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| 21 | #include "llvm/IR/Function.h" |
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| 22 | #include "llvm/IR/Instructions.h" |
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| 23 | #include "llvm/IR/LLVMContext.h" |
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| 24 | |||
| 25 | namespace llvm { |
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| 26 | namespace misexpect { |
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| 27 | |||
| 28 | /// checkBackendInstrumentation - compares PGO counters to the thresholds used |
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| 29 | /// for llvm.expect and warns if the PGO counters are outside of the expected |
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| 30 | /// range. It extracts the expected weights from the MD_prof weights attatched |
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| 31 | /// to the instruction, which are are assumed to come from lowered llvm.expect |
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| 32 | /// intrinsics. The RealWeights parameter and the extracted expected weights are |
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| 33 | /// then passed to verifyMisexpect() for verification |
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| 34 | /// |
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| 35 | /// \param I The Instruction being checked |
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| 36 | /// \param RealWeights A vector of profile weights for each target block |
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| 37 | void checkBackendInstrumentation(Instruction &I, |
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| 38 | const llvm::ArrayRef<uint32_t> RealWeights); |
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| 39 | |||
| 40 | /// checkFrontendInstrumentation - compares PGO counters to the thresholds used |
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| 41 | /// for llvm.expect and warns if the PGO counters are outside of the expected |
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| 42 | /// range. It extracts the expected weights from the MD_prof weights attatched |
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| 43 | /// to the instruction, which are are assumed to come from profiling data |
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| 44 | /// attached by the frontend prior to llvm.expect intrinsic lowering. The |
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| 45 | /// ExpectedWeights parameter and the extracted real weights are then passed to |
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| 46 | /// verifyMisexpect() for verification |
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| 47 | /// |
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| 48 | /// \param I The Instruction being checked |
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| 49 | /// \param ExpectedWeights A vector of the expected weights for each target |
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| 50 | /// block, this determines the threshold values used when emiting diagnostics |
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| 51 | void checkFrontendInstrumentation(Instruction &I, |
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| 52 | const ArrayRef<uint32_t> ExpectedWeights); |
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| 53 | |||
| 54 | /// veryifyMisExpect - compares RealWeights to the thresholds used |
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| 55 | /// for llvm.expect and warns if the PGO counters are outside of the expected |
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| 56 | /// range. |
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| 57 | /// |
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| 58 | /// \param I The Instruction being checked |
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| 59 | /// \param RealWeights A vector of profile weights from the profile data |
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| 60 | /// \param ExpectedWeights A vector of the weights attatch by llvm.expect |
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| 61 | void verifyMisExpect(Instruction &I, ArrayRef<uint32_t> RealWeights, |
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| 62 | const ArrayRef<uint32_t> ExpectedWeights); |
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| 63 | |||
| 64 | /// checkExpectAnnotations - compares PGO counters to the thresholds used |
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| 65 | /// for llvm.expect and warns if the PGO counters are outside of the expected |
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| 66 | /// range. It extracts the expected weights from the MD_prof weights attatched |
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| 67 | /// to the instruction, which are are assumed to come from lowered llvm.expect |
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| 68 | /// intrinsics. The RealWeights parameter and the extracted expected weights are |
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| 69 | /// then passed to verifyMisexpect() for verification. It is a thin wrapper |
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| 70 | /// around the checkFrontendInstrumentation and checkBackendInstrumentation APIs |
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| 71 | /// |
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| 72 | /// \param I The Instruction being checked |
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| 73 | /// \param ExistingWeights A vector of profile weights for each target block |
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| 74 | /// \param IsFrontend A boolean describing if this is Frontend instrumentation |
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| 75 | void checkExpectAnnotations(Instruction &I, |
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| 76 | const ArrayRef<uint32_t> ExistingWeights, |
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| 77 | bool IsFrontend); |
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| 78 | |||
| 79 | } // namespace misexpect |
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| 80 | } // namespace llvm |
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| 81 | |||
| 82 | #endif |