PostRASchedulerList.cpp revision 459525df1e003597077197b5f802bd5d9cd7d94c 
1//===----- SchedulePostRAList.cpp - list scheduler ------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This implements a top-down list scheduler, using standard algorithms.
11// The basic approach uses a priority queue of available nodes to schedule.
12// One at a time, nodes are taken from the priority queue (thus in priority
13// order), checked for legality to schedule, and emitted if legal.
14//
15// Nodes may not be legal to schedule either due to structural hazards (e.g.
16// pipeline or resource constraints) or because an input to the instruction has
17// not completed execution.
18//
19//===----------------------------------------------------------------------===//
20
21#define DEBUG_TYPE "post-RA-sched"
22#include "llvm/CodeGen/Passes.h"
23#include "llvm/CodeGen/MachineFunctionPass.h"
24#include "llvm/Support/Compiler.h"
25#include "llvm/Support/Debug.h"
26using namespace llvm;
27
28namespace {
29  class VISIBILITY_HIDDEN SchedulePostRATDList : public MachineFunctionPass {
30  public:
31    static char ID;
32    SchedulePostRATDList() : MachineFunctionPass((intptr_t)&ID) {}
33  private:
34    MachineFunction *MF;
35    const TargetMachine *TM;
36  public:
37    const char *getPassName() const {
38      return "Post RA top-down list latency scheduler (STUB)";
39    }
40
41    bool runOnMachineFunction(MachineFunction &Fn);
42  };
43  char SchedulePostRATDList::ID = 0;
44}
45
46bool SchedulePostRATDList::runOnMachineFunction(MachineFunction &Fn) {
47  DOUT << "SchedulePostRATDList\n";
48  MF = &Fn;
49  TM = &MF->getTarget();
50
51  // Loop over all of the basic blocks
52  for (MachineFunction::iterator MBB = Fn.begin(), MBBe = Fn.end();
53       MBB != MBBe; ++MBB)
54    ;
55
56  return true;
57}
58
59
60//===----------------------------------------------------------------------===//
61//                         Public Constructor Functions
62//===----------------------------------------------------------------------===//
63
64FunctionPass *llvm::createPostRAScheduler() {
65  return new SchedulePostRATDList();
66}
67