1 //===----- SchedulePostRAList.cpp - list scheduler ------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Dale Johannesen and is distributed under the
6 // University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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.
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.
19 //===----------------------------------------------------------------------===//
21 #define DEBUG_TYPE "post-RA-sched"
22 #include "llvm/CodeGen/Passes.h"
23 #include "llvm/CodeGen/MachineFunctionPass.h"
24 #include "llvm/Support/Debug.h"
25 //#include "llvm/ADT/Statistic.h"
28 #include "llvm/Support/CommandLine.h"
32 bool NoPostRAScheduling;
34 // When this works it will be on by default.
36 DisablePostRAScheduler("disable-post-RA-scheduler",
37 cl::desc("Disable scheduling after register allocation"),
38 cl::location(NoPostRAScheduling),
41 class VISIBILITY_HIDDEN SchedulePostRATDList : public MachineFunctionPass {
44 SchedulePostRATDList() : MachineFunctionPass((intptr_t)&ID) {}
47 const TargetMachine *TM;
49 const char *getPassName() const {
50 return "Post RA top-down list latency scheduler (STUB)";
53 bool runOnMachineFunction(MachineFunction &Fn);
55 char SchedulePostRATDList::ID = 0;
58 bool SchedulePostRATDList::runOnMachineFunction(MachineFunction &Fn) {
59 if (NoPostRAScheduling)
62 DOUT << "SchedulePostRATDList\n";
64 TM = &MF->getTarget();
66 // Loop over all of the basic blocks
67 for (MachineFunction::iterator MBB = Fn.begin(), MBBe = Fn.end();
75 //===----------------------------------------------------------------------===//
76 // Public Constructor Functions
77 //===----------------------------------------------------------------------===//
79 FunctionPass *llvm::createPostRAScheduler() {
80 return new SchedulePostRATDList();