class IDFCalculatorBase

Declaration

template <class NodeTy, bool IsPostDom>
class IDFCalculatorBase { /* full declaration omitted */ };

Description

Determine the iterated dominance frontier, given a set of defining blocks, and optionally, a set of live-in blocks. In turn, the results can be used to place phi nodes. This algorithm is a linear time computation of Iterated Dominance Frontiers, pruned using the live-in set. By default, liveness is not used to prune the IDF computation. The template parameters should be of a CFG block type.

Declared at: llvm/include/llvm/Support/GenericIteratedDominanceFrontier.h:57

Templates

NodeTy
bool IsPostDom

Method Overview

Methods

IDFCalculatorBase<NodeTy, IsPostDom>(
    DominatorTreeBase<NodeTy, IsPostDom>& DT)

Declared at: llvm/include/llvm/Support/GenericIteratedDominanceFrontier.h:64

Parameters

DominatorTreeBase<NodeTy, IsPostDom>& DT

IDFCalculatorBase<NodeTy, IsPostDom>(
    DominatorTreeBase<NodeTy, IsPostDom>& DT,
    const llvm::IDFCalculatorBase::
        ChildrenGetterTy& C)

Declared at: llvm/include/llvm/Support/GenericIteratedDominanceFrontier.h:66

Parameters

DominatorTreeBase<NodeTy, IsPostDom>& DT
const llvm::IDFCalculatorBase::ChildrenGetterTy& C

void calculate(
    SmallVectorImpl<NodeTy*>& IDFBlocks)

Description

Calculate iterated dominance frontiers This uses the linear-time phi algorithm based on DJ-graphs mentioned in the file-level comment. It performs DF->IDF pruning using the live-in set, to avoid computing the IDF for blocks where an inserted PHI node would be dead.

Declared at: llvm/include/llvm/Support/GenericIteratedDominanceFrontier.h:102

Parameters

SmallVectorImpl<NodeTy*>& IDFBlocks

void resetLiveInBlocks()

Description

Reset the live-in block set to be empty, and tell the IDF calculator to not use liveness anymore.

Declared at: llvm/include/llvm/Support/GenericIteratedDominanceFrontier.h:91

void setDefiningBlocks(
    const SmallPtrSetImpl<NodeTy*>& Blocks)

Description

Give the IDF calculator the set of blocks in which the value is defined. This is equivalent to the set of starting blocks it should be calculating the IDF for (though later gets pruned based on liveness). Note: This set *must* live for the entire lifetime of the IDF calculator.

Declared at: llvm/include/llvm/Support/GenericIteratedDominanceFrontier.h:75

Parameters

const SmallPtrSetImpl<NodeTy*>& Blocks

void setLiveInBlocks(
    const SmallPtrSetImpl<NodeTy*>& Blocks)

Description

Give the IDF calculator the set of blocks in which the value is live on entry to the block. This is used to prune the IDF calculation to not include blocks where any phi insertion would be dead. Note: This set *must* live for the entire lifetime of the IDF calculator.

Declared at: llvm/include/llvm/Support/GenericIteratedDominanceFrontier.h:84

Parameters

const SmallPtrSetImpl<NodeTy*>& Blocks