CalledValuePropagation.cpp File Reference

#include "llvm/Transforms/IPO/CalledValuePropagation.h"
#include "llvm/Analysis/SparsePropagation.h"
#include "llvm/Analysis/ValueLatticeUtils.h"
#include "llvm/IR/MDBuilder.h"
#include "llvm/InitializePasses.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Transforms/IPO.h"

Include dependency graph for CalledValuePropagation.cpp:

Go to the source code of this file.

Classes
struct	llvm::LatticeKeyInfo< CVPLatticeKey >
	A specialization of LatticeKeyInfo for CVPLatticeKeys. More...

Namespaces
	llvm
	---------------------— PointerInfo ------------------------------------—

Macros
#define	DEBUG_TYPE   "called-value-propagation"

Functions
static bool	runCVP (Module &M)
	INITIALIZE_PASS (CalledValuePropagationLegacyPass, "called-value-propagation", "Called Value Propagation", false, false) ModulePass *llvm

Variables
static cl::opt< unsigned >	MaxFunctionsPerValue ("cvp-max-functions-per-value", cl::Hidden, cl::init(4), cl::desc("The maximum number of functions to track per lattice value"))
	The maximum number of functions to track per lattice value. More...

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "called-value-propagation"

Definition at line 28 of file CalledValuePropagation.cpp.

Function Documentation

INITIALIZE_PASS()

INITIALIZE_PASS	(	CalledValuePropagationLegacyPass	,
		"called-value-propagation"	,
		"Called Value Propagation"	,
		false	,
		false
	)

Definition at line 429 of file CalledValuePropagation.cpp.

runCVP()

static bool runCVP ( Module &  M )

static

Definition at line 368 of file CalledValuePropagation.cpp.

References llvm::canTrackArgumentsInterprocedurally(), llvm::MDBuilder::createCallees(), F, llvm::SparseSolver< LatticeKey, LatticeVal, KeyInfo >::getExistingValueState(), M, llvm::SparseSolver< LatticeKey, LatticeVal, KeyInfo >::MarkBlockExecutable(), Register, and llvm::SparseSolver< LatticeKey, LatticeVal, KeyInfo >::Solve().

Referenced by llvm::CalledValuePropagationPass::run().

Variable Documentation

MaxFunctionsPerValue

cl::opt<unsigned> MaxFunctionsPerValue("cvp-max-functions-per-value", cl::Hidden, cl::init(4), cl::desc("The maximum number of functions to track per lattice value"))

static

The maximum number of functions to track per lattice value.

Once the number of functions a call site can possibly target exceeds this threshold, it's lattice value becomes overdefined. The number of possible lattice values is bounded by Ch(F, M), where F is the number of functions in the module and M is MaxFunctionsPerValue. As such, this value should be kept very small. We likely can't do anything useful for call sites with a large number of possible targets, anyway.