| //===- PseudoProbe.h - Pseudo Probe IR Helpers ------------------*- C++ -*-===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Pseudo probe IR intrinsic and dwarf discriminator manipulation routines. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_IR_PSEUDOPROBE_H |
| #define LLVM_IR_PSEUDOPROBE_H |
| |
| #include "llvm/ADT/Optional.h" |
| #include <cassert> |
| #include <cstdint> |
| #include <limits> |
| |
| namespace llvm { |
| |
| class Instruction; |
| |
| constexpr const char *PseudoProbeDescMetadataName = "llvm.pseudo_probe_desc"; |
| |
| enum class PseudoProbeType { Block = 0, IndirectCall, DirectCall }; |
| |
| // The saturated distrution factor representing 100% for block probes. |
| constexpr static uint64_t PseudoProbeFullDistributionFactor = |
| std::numeric_limits<uint64_t>::max(); |
| |
| struct PseudoProbeDwarfDiscriminator { |
| public: |
| // The following APIs encodes/decodes per-probe information to/from a |
| // 32-bit integer which is organized as: |
| // [2:0] - 0x7, this is reserved for regular discriminator, |
| // see DWARF discriminator encoding rule |
| // [18:3] - probe id |
| // [25:19] - probe distribution factor |
| // [28:26] - probe type, see PseudoProbeType |
| // [31:29] - reserved for probe attributes |
| static uint32_t packProbeData(uint32_t Index, uint32_t Type, uint32_t Flags, |
| uint32_t Factor) { |
| assert(Index <= 0xFFFF && "Probe index too big to encode, exceeding 2^16"); |
| assert(Type <= 0x7 && "Probe type too big to encode, exceeding 7"); |
| assert(Flags <= 0x7); |
| assert(Factor <= 100 && |
| "Probe distribution factor too big to encode, exceeding 100"); |
| return (Index << 3) | (Factor << 19) | (Type << 26) | 0x7; |
| } |
| |
| static uint32_t extractProbeIndex(uint32_t Value) { |
| return (Value >> 3) & 0xFFFF; |
| } |
| |
| static uint32_t extractProbeType(uint32_t Value) { |
| return (Value >> 26) & 0x7; |
| } |
| |
| static uint32_t extractProbeAttributes(uint32_t Value) { |
| return (Value >> 29) & 0x7; |
| } |
| |
| static uint32_t extractProbeFactor(uint32_t Value) { |
| return (Value >> 19) & 0x7F; |
| } |
| |
| // The saturated distrution factor representing 100% for callsites. |
| constexpr static uint8_t FullDistributionFactor = 100; |
| }; |
| |
| struct PseudoProbe { |
| uint32_t Id; |
| uint32_t Type; |
| uint32_t Attr; |
| // Distribution factor that estimates the portion of the real execution count. |
| // A saturated distribution factor stands for 1.0 or 100%. A pesudo probe has |
| // a factor with the value ranged from 0.0 to 1.0. |
| float Factor; |
| }; |
| |
| Optional<PseudoProbe> extractProbe(const Instruction &Inst); |
| |
| void setProbeDistributionFactor(Instruction &Inst, float Factor); |
| } // end namespace llvm |
| |
| #endif // LLVM_IR_PSEUDOPROBE_H |