class MachineOptimizationRemarkEmitter

Declaration

class MachineOptimizationRemarkEmitter { /* full declaration omitted */ };

Description

The optimization diagnostic interface. It allows reporting when optimizations are performed and when they are not along with the reasons for it. Hotness information of the corresponding code region can be included in the remark if DiagnosticsHotnessRequested is enabled in the LLVM context.

Declared at: llvm/include/llvm/CodeGen/MachineOptimizationRemarkEmitter.h:151

Member Variables

private llvm::MachineFunction& MF

private llvm::MachineBlockFrequencyInfo* MBFI

MBFI is only set if hotness is requested.

Method Overview

• public MachineOptimizationRemarkEmitter(llvm::MachineFunction & MF, llvm::MachineBlockFrequencyInfo * MBFI)
• public bool allowExtraAnalysis(llvm::StringRef PassName) const
• private Optional<uint64_t> computeHotness(const llvm::MachineBasicBlock & MBB)
• private void computeHotness(llvm::DiagnosticInfoMIROptimization & Remark)
• public void emit(llvm::DiagnosticInfoOptimizationBase & OptDiag)
• public template <typename T>void emit(T RemarkBuilder, decltype(RemarkBuilder()) * = nullptr)
• public llvm::MachineBlockFrequencyInfo * getBFI()
• private bool shouldEmitVerbose()

Methods

¶MachineOptimizationRemarkEmitter(
    llvm::MachineFunction& MF,
    llvm::MachineBlockFrequencyInfo* MBFI)

Declared at: llvm/include/llvm/CodeGen/MachineOptimizationRemarkEmitter.h:153

Parameters

llvm::MachineFunction& MF

llvm::MachineBlockFrequencyInfo* MBFI

¶bool allowExtraAnalysis(
    llvm::StringRef PassName) const

Description

Whether we allow for extra compile-time budget to perform more analysis to be more informative. This is useful to enable additional missed optimizations to be reported that are normally too noisy. In this mode, we can use the extra analysis (1) to filter trivial false positives or (2) to provide more context so that non-trivial false positives can be quickly detected by the user.

Declared at: llvm/include/llvm/CodeGen/MachineOptimizationRemarkEmitter.h:167

Parameters

llvm::StringRef PassName

¶Optional<uint64_t> computeHotness(
    const llvm::MachineBasicBlock& MBB)

Description

Compute hotness from IR value (currently assumed to be a block) if PGO is available.

Declared at: llvm/include/llvm/CodeGen/MachineOptimizationRemarkEmitter.h:204

Parameters

const llvm::MachineBasicBlock& MBB

¶void computeHotness(
    llvm::DiagnosticInfoMIROptimization& Remark)

Description

Similar but use value from \p OptDiag and update hotness there.

Declared at: llvm/include/llvm/CodeGen/MachineOptimizationRemarkEmitter.h:207

Parameters

llvm::DiagnosticInfoMIROptimization& Remark

¶void emit(
    llvm::DiagnosticInfoOptimizationBase& OptDiag)

Description

Emit an optimization remark.

Declared at: llvm/include/llvm/CodeGen/MachineOptimizationRemarkEmitter.h:158

Parameters

llvm::DiagnosticInfoOptimizationBase& OptDiag

¶template <typename T>
void emit(T RemarkBuilder,
          decltype(RemarkBuilder())* = nullptr)

Description

Take a lambda that returns a remark which will be emitted. Second argument is only used to restrict this to functions.

Declared at: llvm/include/llvm/CodeGen/MachineOptimizationRemarkEmitter.h:177

Templates

T

Parameters

T RemarkBuilder

decltype(RemarkBuilder())* = nullptr

¶llvm::MachineBlockFrequencyInfo* getBFI()

Declared at: llvm/include/llvm/CodeGen/MachineOptimizationRemarkEmitter.h:192

¶bool shouldEmitVerbose()

Description

Only allow verbose messages if we know we're filtering by hotness (BFI is only set in this case).

Declared at: llvm/include/llvm/CodeGen/MachineOptimizationRemarkEmitter.h:211