aboutsummaryrefslogtreecommitdiff
path: root/lib/Target/ARM/ARMTargetTransformInfo.cpp
blob: 7a830dd73117a0b51aa075867391e6c7427126a7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
//===-- ARMTargetTransformInfo.cpp - ARM specific TTI pass ----------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
/// \file
/// This file implements a TargetTransformInfo analysis pass specific to the
/// ARM target machine. It uses the target's detailed information to provide
/// more precise answers to certain TTI queries, while letting the target
/// independent and default TTI implementations handle the rest.
///
//===----------------------------------------------------------------------===//

#define DEBUG_TYPE "armtti"
#include "ARM.h"
#include "ARMTargetMachine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/TargetTransformInfo.h"
using namespace llvm;

// Declare the pass initialization routine locally as target-specific passes
// don't havve a target-wide initialization entry point, and so we rely on the
// pass constructor initialization.
namespace llvm {
void initializeARMTTIPass(PassRegistry &);
}

namespace {

class ARMTTI : public ImmutablePass, public TargetTransformInfo {
  const ARMBaseTargetMachine *TM;
  const ARMSubtarget *ST;

  /// Estimate the overhead of scalarizing an instruction. Insert and Extract
  /// are set if the result needs to be inserted and/or extracted from vectors.
  unsigned getScalarizationOverhead(Type *Ty, bool Insert, bool Extract) const;

public:
  ARMTTI() : ImmutablePass(ID), TM(0), ST(0) {
    llvm_unreachable("This pass cannot be directly constructed");
  }

  ARMTTI(const ARMBaseTargetMachine *TM)
      : ImmutablePass(ID), TM(TM), ST(TM->getSubtargetImpl()) {
    initializeARMTTIPass(*PassRegistry::getPassRegistry());
  }

  virtual void initializePass() {
    pushTTIStack(this);
  }

  virtual void finalizePass() {
    popTTIStack();
  }

  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
    TargetTransformInfo::getAnalysisUsage(AU);
  }

  /// Pass identification.
  static char ID;

  /// Provide necessary pointer adjustments for the two base classes.
  virtual void *getAdjustedAnalysisPointer(const void *ID) {
    if (ID == &TargetTransformInfo::ID)
      return (TargetTransformInfo*)this;
    return this;
  }

  /// \name Scalar TTI Implementations
  /// @{

  virtual unsigned getIntImmCost(const APInt &Imm, Type *Ty) const;

  /// @}
};

} // end anonymous namespace

INITIALIZE_AG_PASS(ARMTTI, TargetTransformInfo, "armtti",
                   "ARM Target Transform Info", true, true, false)
char ARMTTI::ID = 0;

ImmutablePass *
llvm::createARMTargetTransformInfoPass(const ARMBaseTargetMachine *TM) {
  return new ARMTTI(TM);
}


unsigned ARMTTI::getIntImmCost(const APInt &Imm, Type *Ty) const {
  assert(Ty->isIntegerTy());

  unsigned Bits = Ty->getPrimitiveSizeInBits();
  if (Bits == 0 || Bits > 32)
    return 4;

  int32_t SImmVal = Imm.getSExtValue();
  uint32_t ZImmVal = Imm.getZExtValue();
  if (!ST->isThumb()) {
    if ((SImmVal >= 0 && SImmVal < 65536) ||
        (ARM_AM::getSOImmVal(ZImmVal) != -1) ||
        (ARM_AM::getSOImmVal(~ZImmVal) != -1))
      return 1;
    return ST->hasV6T2Ops() ? 2 : 3;
  } else if (ST->isThumb2()) {
    if ((SImmVal >= 0 && SImmVal < 65536) ||
        (ARM_AM::getT2SOImmVal(ZImmVal) != -1) ||
        (ARM_AM::getT2SOImmVal(~ZImmVal) != -1))
      return 1;
    return ST->hasV6T2Ops() ? 2 : 3;
  } else /*Thumb1*/ {
    if (SImmVal >= 0 && SImmVal < 256)
      return 1;
    if ((~ZImmVal < 256) || ARM_AM::isThumbImmShiftedVal(ZImmVal))
      return 2;
    // Load from constantpool.
    return 3;
  }
  return 2;
}