114 lines
3.5 KiB
C++
114 lines
3.5 KiB
C++
//===- GISelWorkList.h - Worklist for GISel passes ----*- C++ -*-===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_GISEL_WORKLIST_H
|
|
#define LLVM_GISEL_WORKLIST_H
|
|
|
|
#include "llvm/ADT/DenseMap.h"
|
|
#include "llvm/ADT/SmallVector.h"
|
|
|
|
namespace llvm {
|
|
|
|
class MachineInstr;
|
|
class MachineFunction;
|
|
|
|
// Worklist which mostly works similar to InstCombineWorkList, but on
|
|
// MachineInstrs. The main difference with something like a SetVector is that
|
|
// erasing an element doesn't move all elements over one place - instead just
|
|
// nulls out the element of the vector.
|
|
//
|
|
// FIXME: Does it make sense to factor out common code with the
|
|
// instcombinerWorkList?
|
|
template<unsigned N>
|
|
class GISelWorkList {
|
|
SmallVector<MachineInstr *, N> Worklist;
|
|
DenseMap<MachineInstr *, unsigned> WorklistMap;
|
|
|
|
#ifndef NDEBUG
|
|
bool Finalized = true;
|
|
#endif
|
|
|
|
public:
|
|
GISelWorkList() : WorklistMap(N) {}
|
|
|
|
bool empty() const { return WorklistMap.empty(); }
|
|
|
|
unsigned size() const { return WorklistMap.size(); }
|
|
|
|
// Since we don't know ahead of time how many instructions we're going to add
|
|
// to the worklist, and migrating densemap's elements is quite expensive
|
|
// everytime we resize, only insert to the smallvector (typically during the
|
|
// initial phase of populating lists). Before the worklist can be used,
|
|
// finalize should be called. Also assert with NDEBUG if list is ever used
|
|
// without finalizing. Note that unlike insert, we won't check for duplicates
|
|
// - so the ideal place to use this is during the initial prepopulating phase
|
|
// of most passes.
|
|
void deferred_insert(MachineInstr *I) {
|
|
Worklist.push_back(I);
|
|
#ifndef NDEBUG
|
|
Finalized = false;
|
|
#endif
|
|
}
|
|
|
|
// This should only be called when using deferred_insert.
|
|
// This asserts that the WorklistMap is empty, and then
|
|
// inserts all the elements in the Worklist into the map.
|
|
// It also asserts if there are any duplicate elements found.
|
|
void finalize() {
|
|
assert(WorklistMap.empty() && "Expecting empty worklistmap");
|
|
if (Worklist.size() > N)
|
|
WorklistMap.reserve(Worklist.size());
|
|
for (unsigned i = 0; i < Worklist.size(); ++i)
|
|
if (!WorklistMap.try_emplace(Worklist[i], i).second)
|
|
llvm_unreachable("Duplicate elements in the list");
|
|
#ifndef NDEBUG
|
|
Finalized = true;
|
|
#endif
|
|
}
|
|
|
|
/// Add the specified instruction to the worklist if it isn't already in it.
|
|
void insert(MachineInstr *I) {
|
|
assert(Finalized && "GISelWorkList used without finalizing");
|
|
if (WorklistMap.try_emplace(I, Worklist.size()).second)
|
|
Worklist.push_back(I);
|
|
}
|
|
|
|
/// Remove I from the worklist if it exists.
|
|
void remove(const MachineInstr *I) {
|
|
assert((Finalized || WorklistMap.empty()) && "Neither finalized nor empty");
|
|
auto It = WorklistMap.find(I);
|
|
if (It == WorklistMap.end())
|
|
return; // Not in worklist.
|
|
|
|
// Don't bother moving everything down, just null out the slot.
|
|
Worklist[It->second] = nullptr;
|
|
|
|
WorklistMap.erase(It);
|
|
}
|
|
|
|
void clear() {
|
|
Worklist.clear();
|
|
WorklistMap.clear();
|
|
}
|
|
|
|
MachineInstr *pop_back_val() {
|
|
assert(Finalized && "GISelWorkList used without finalizing");
|
|
MachineInstr *I;
|
|
do {
|
|
I = Worklist.pop_back_val();
|
|
} while(!I);
|
|
assert(I && "Pop back on empty worklist");
|
|
WorklistMap.erase(I);
|
|
return I;
|
|
}
|
|
};
|
|
|
|
} // end namespace llvm.
|
|
|
|
#endif
|