blob: c2103fb233f82e8144a298125e3cc88853c2daf0 (
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
125
126
|
//=- llvm/CodeGen/ScoreboardHazardRecognizer.h - Schedule Support -*- C++ -*-=//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the ScoreboardHazardRecognizer class, which
// encapsulates hazard-avoidance heuristics for scheduling, based on the
// scheduling itineraries specified for the target.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_SCOREBOARDHAZARDRECOGNIZER_H
#define LLVM_CODEGEN_SCOREBOARDHAZARDRECOGNIZER_H
#include "llvm/CodeGen/ScheduleHazardRecognizer.h"
#include "llvm/Support/DataTypes.h"
#include <cassert>
#include <cstring>
namespace llvm {
class InstrItineraryData;
class ScheduleDAG;
class SUnit;
class ScoreboardHazardRecognizer : public ScheduleHazardRecognizer {
// Scoreboard to track function unit usage. Scoreboard[0] is a
// mask of the FUs in use in the cycle currently being
// schedule. Scoreboard[1] is a mask for the next cycle. The
// Scoreboard is used as a circular buffer with the current cycle
// indicated by Head.
//
// Scoreboard always counts cycles in forward execution order. If used by a
// bottom-up scheduler, then the scoreboard cycles are the inverse of the
// scheduler's cycles.
class Scoreboard {
unsigned *Data;
// The maximum number of cycles monitored by the Scoreboard. This
// value is determined based on the target itineraries to ensure
// that all hazards can be tracked.
size_t Depth;
// Indices into the Scoreboard that represent the current cycle.
size_t Head;
public:
Scoreboard():Data(NULL), Depth(0), Head(0) { }
~Scoreboard() {
delete[] Data;
}
size_t getDepth() const { return Depth; }
unsigned& operator[](size_t idx) const {
// Depth is expected to be a power-of-2.
assert(Depth && !(Depth & (Depth - 1)) &&
"Scoreboard was not initialized properly!");
return Data[(Head + idx) & (Depth-1)];
}
void reset(size_t d = 1) {
if (Data == NULL) {
Depth = d;
Data = new unsigned[Depth];
}
memset(Data, 0, Depth * sizeof(Data[0]));
Head = 0;
}
void advance() {
Head = (Head + 1) & (Depth-1);
}
void recede() {
Head = (Head - 1) & (Depth-1);
}
// Print the scoreboard.
void dump() const;
};
#ifndef NDEBUG
// Support for tracing ScoreboardHazardRecognizer as a component within
// another module. Follows the current thread-unsafe model of tracing.
static const char *DebugType;
#endif
// Itinerary data for the target.
const InstrItineraryData *ItinData;
const ScheduleDAG *DAG;
/// IssueWidth - Max issue per cycle. 0=Unknown.
unsigned IssueWidth;
/// IssueCount - Count instructions issued in this cycle.
unsigned IssueCount;
Scoreboard ReservedScoreboard;
Scoreboard RequiredScoreboard;
public:
ScoreboardHazardRecognizer(const InstrItineraryData *ItinData,
const ScheduleDAG *DAG,
const char *ParentDebugType = "");
/// atIssueLimit - Return true if no more instructions may be issued in this
/// cycle.
virtual bool atIssueLimit() const;
// Stalls provides an cycle offset at which SU will be scheduled. It will be
// negative for bottom-up scheduling.
virtual HazardType getHazardType(SUnit *SU, int Stalls);
virtual void Reset();
virtual void EmitInstruction(SUnit *SU);
virtual void AdvanceCycle();
virtual void RecedeCycle();
};
}
#endif //!LLVM_CODEGEN_SCOREBOARDHAZARDRECOGNIZER_H
|
