maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[MachineBlockPlacement] Clean up data structures a bit. 

No functionality change intended.

llvm-svn: 300059
This commit is contained in:
Benjamin Kramer 2017-04-12 13:26:28 +00:00
parent 592dbea779
commit d71461c209
1 changed files with 17 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
llvm/lib/CodeGen/MachineBlockPlacement.cpp
View File

@ -50,7 +50,6 @@
#include "llvm/Target/TargetLowering.h" #include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetSubtargetInfo.h" #include "llvm/Target/TargetSubtargetInfo.h"
#include <algorithm> #include <algorithm>
#include <forward_list>
#include <functional> #include <functional>
#include <utility> #include <utility>
using namespace llvm; using namespace llvm;
@ -459,7 +458,7 @@ class MachineBlockPlacement : public MachineFunctionPass {
/// Get the best pair of non-conflicting edges. /// Get the best pair of non-conflicting edges.
static std::pair<WeightedEdge, WeightedEdge> getBestNonConflictingEdges( static std::pair<WeightedEdge, WeightedEdge> getBestNonConflictingEdges(
const MachineBasicBlock *BB, const MachineBasicBlock *BB,
SmallVector<SmallVector<WeightedEdge, 8>, 2> &Edges); MutableArrayRef<SmallVector<WeightedEdge, 8>> Edges);
/// Returns true if a block can tail duplicate into all unplaced /// Returns true if a block can tail duplicate into all unplaced
/// predecessors. Filters based on loop. /// predecessors. Filters based on loop.
bool canTailDuplicateUnplacedPreds( bool canTailDuplicateUnplacedPreds(
@ -882,8 +881,8 @@ std::pair<MachineBlockPlacement::WeightedEdge,
MachineBlockPlacement::WeightedEdge> MachineBlockPlacement::WeightedEdge>
MachineBlockPlacement::getBestNonConflictingEdges( MachineBlockPlacement::getBestNonConflictingEdges(
const MachineBasicBlock *BB, const MachineBasicBlock *BB,
SmallVector<SmallVector<MachineBlockPlacement::WeightedEdge, 8>, 2> MutableArrayRef<SmallVector<MachineBlockPlacement::WeightedEdge, 8>>
&Edges) { Edges) {
// Sort the edges, and then for each successor, find the best incoming // Sort the edges, and then for each successor, find the best incoming
// predecessor. If the best incoming predecessors aren't the same, // predecessor. If the best incoming predecessors aren't the same,
// then that is clearly the best layout. If there is a conflict, one of the // then that is clearly the best layout. If there is a conflict, one of the
@ -941,7 +940,7 @@ MachineBlockPlacement::getBestTrellisSuccessor(
return Result; return Result;
// Collect the edge frequencies of all edges that form the trellis. // Collect the edge frequencies of all edges that form the trellis.
SmallVector<SmallVector<WeightedEdge, 8>, 2> Edges(2); SmallVector<WeightedEdge, 8> Edges[2];
int SuccIndex = 0; int SuccIndex = 0;
for (auto Succ : ViableSuccs) { for (auto Succ : ViableSuccs) {
for (MachineBasicBlock *SuccPred : Succ->predecessors()) { for (MachineBasicBlock *SuccPred : Succ->predecessors()) {
@ -1085,23 +1084,20 @@ bool MachineBlockPlacement::canTailDuplicateUnplacedPreds(
/// We believe that 2 and 3 are common enough to justify the small margin in 1. /// We believe that 2 and 3 are common enough to justify the small margin in 1.
void MachineBlockPlacement::precomputeTriangleChains() { void MachineBlockPlacement::precomputeTriangleChains() {
struct TriangleChain { struct TriangleChain {
unsigned Count; std::vector<MachineBasicBlock *> Edges;
std::forward_list<MachineBasicBlock*> Edges; TriangleChain(MachineBasicBlock *src, MachineBasicBlock *dst)
TriangleChain(MachineBasicBlock* src, MachineBasicBlock *dst) { : Edges({src, dst}) {}
Edges.push_front(src);
Edges.push_front(dst);
Count = 1;
}
void append(MachineBasicBlock *dst) { void append(MachineBasicBlock *dst) {
assert(!Edges.empty() && Edges.front()->isSuccessor(dst) && assert(getKey()->isSuccessor(dst) &&
"Attempting to append a block that is not a successor."); "Attempting to append a block that is not a successor.");
Edges.push_front(dst); Edges.push_back(dst);
++Count;
} }
MachineBasicBlock *getKey() { unsigned count() const { return Edges.size() - 1; }
return Edges.front();
MachineBasicBlock *getKey() const {
return Edges.back();
} }
}; };
@ -1174,11 +1170,11 @@ void MachineBlockPlacement::precomputeTriangleChains() {
// Benchmarking has shown that due to branch correlation duplicating 2 or // Benchmarking has shown that due to branch correlation duplicating 2 or
// more triangles is profitable, despite the calculations assuming // more triangles is profitable, despite the calculations assuming
// independence. // independence.
if (Chain.Count < TriangleChainCount) if (Chain.count() < TriangleChainCount)
continue; continue;
MachineBasicBlock *dst = Chain.Edges.front(); MachineBasicBlock *dst = Chain.Edges.back();
Chain.Edges.pop_front(); Chain.Edges.pop_back();
for (MachineBasicBlock *src : Chain.Edges) { for (MachineBasicBlock *src : reverse(Chain.Edges)) {
DEBUG(dbgs() << "Marking edge: " << getBlockName(src) << "->" << DEBUG(dbgs() << "Marking edge: " << getBlockName(src) << "->" <<
getBlockName(dst) << " as pre-computed based on triangles.\n"); getBlockName(dst) << " as pre-computed based on triangles.\n");
ComputedEdges[src] = { dst, true }; ComputedEdges[src] = { dst, true };