TargetSubtargetInfo.cpp revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
1//===-- TargetSubtargetInfo.cpp - General Target Information ---------------==//
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 file describes the general parts of a Subtarget.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Support/CommandLine.h"
15#include "llvm/ADT/SmallVector.h"
16#include "llvm/Target/TargetSubtargetInfo.h"
17using namespace llvm;
18
19//---------------------------------------------------------------------------
20// TargetSubtargetInfo Class
21//
22TargetSubtargetInfo::TargetSubtargetInfo() {}
23
24TargetSubtargetInfo::~TargetSubtargetInfo() {}
25
26// Temporary option to compare overall performance change when moving from the
27// SD scheduler to the MachineScheduler pass pipeline. This is convenient for
28// benchmarking during the transition from SD to MI scheduling. Once armv7 makes
29// the switch, it should go away. The normal way to enable/disable the
30// MachineScheduling pass itself is by using -enable-misched. For targets that
31// already use MI sched (via MySubTarget::enableMachineScheduler())
32// -misched-bench=false negates the subtarget hook.
33static cl::opt<bool> BenchMachineSched("misched-bench", cl::Hidden,
34    cl::desc("Migrate from the target's default SD scheduler to MI scheduler"));
35
36bool TargetSubtargetInfo::useMachineScheduler() const {
37  if (BenchMachineSched.getNumOccurrences())
38    return BenchMachineSched;
39  return enableMachineScheduler();
40}
41
42bool TargetSubtargetInfo::enableMachineScheduler() const {
43  return false;
44}
45
46bool TargetSubtargetInfo::enablePostRAScheduler(
47          CodeGenOpt::Level OptLevel,
48          AntiDepBreakMode& Mode,
49          RegClassVector& CriticalPathRCs) const {
50  Mode = ANTIDEP_NONE;
51  CriticalPathRCs.clear();
52  return false;
53}
54
55bool TargetSubtargetInfo::useAA() const {
56  return false;
57}
58