class OptBisect

Declaration

class OptBisect : public OptPassGate { /* full declaration omitted */ };

Description

This class implements a mechanism to disable passes and individual optimizations at compile time based on a command line option (-opt-bisect-limit) in order to perform a bisecting search for optimization-related problems.

Declared at: llvm/include/llvm/IR/OptBisect.h:44

Inherits from: OptPassGate

Member Variables

private int BisectLimit = Disabled
private int LastBisectNum = 0
public static const int Disabled = std::numeric_limits<int>::max()

Method Overview

Inherited from OptPassGate:

Methods

OptBisect()

Description

Default constructor. Initializes the state to "disabled". The bisection will be enabled by the cl::opt call-back when the command line option is processed. Clients should not instantiate this class directly. All access should go through LLVMContext.

Declared at: llvm/include/llvm/IR/OptBisect.h:51

bool checkPass(const llvm::StringRef PassName,
               const llvm::StringRef TargetDesc)

Description

Checks the bisect limit to determine if the specified pass should run. If the bisect limit is set to -1, the function prints a message describing the pass and the bisect number assigned to it and return true. Otherwise, the function prints a message with the bisect number assigned to the pass and indicating whether or not the pass will be run and return true if the bisect limit has not yet been exceeded or false if it has. Most passes should not call this routine directly. Instead, they are called through helper routines provided by the pass base classes. For instance, function passes should call FunctionPass::skipFunction().

Declared at: llvm/include/llvm/IR/OptBisect.h:81

Parameters

const llvm::StringRef PassName
const llvm::StringRef TargetDesc

bool isEnabled() const

Description

isEnabled() should return true before calling shouldRunPass().

Declared at: llvm/include/llvm/IR/OptBisect.h:61

void setLimit(int Limit)

Description

Set the new optimization limit and reset the counter. Passing OptBisect::Disabled disables the limiting.

Declared at: llvm/include/llvm/IR/OptBisect.h:65

Parameters

int Limit

bool shouldRunPass(const llvm::Pass* P,
                   llvm::StringRef IRDescription)

Description

Checks the bisect limit to determine if the specified pass should run. This forwards to checkPass().

Declared at: llvm/include/llvm/IR/OptBisect.h:58

Parameters

const llvm::Pass* P
llvm::StringRef IRDescription

virtual ~OptBisect()

Declared at: llvm/include/llvm/IR/OptBisect.h:53