blob: 4f5eb223d42fffbbec248e4fba07c576d264ea0f (
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
|
// Copyright 2013 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_CRANKSHAFT_ARM64_LITHIUM_GAP_RESOLVER_ARM64_H_
#define V8_CRANKSHAFT_ARM64_LITHIUM_GAP_RESOLVER_ARM64_H_
#include "src/crankshaft/arm64/delayed-masm-arm64.h"
#include "src/crankshaft/lithium.h"
namespace v8 {
namespace internal {
class LCodeGen;
class LGapResolver;
class DelayedGapMasm : public DelayedMasm {
public:
DelayedGapMasm(LCodeGen* owner, MacroAssembler* masm)
: DelayedMasm(owner, masm, root) {
// We use the root register as an extra scratch register.
// The root register has two advantages:
// - It is not in crankshaft allocatable registers list, so it can't
// interfere with the allocatable registers.
// - We don't need to push it on the stack, as we can reload it with its
// value once we have finish.
}
void EndDelayedUse();
};
class LGapResolver BASE_EMBEDDED {
public:
explicit LGapResolver(LCodeGen* owner);
// Resolve a set of parallel moves, emitting assembler instructions.
void Resolve(LParallelMove* parallel_move);
private:
// Build the initial list of moves.
void BuildInitialMoveList(LParallelMove* parallel_move);
// Perform the move at the moves_ index in question (possibly requiring
// other moves to satisfy dependencies).
void PerformMove(int index);
// If a cycle is found in the series of moves, save the blocking value to
// a scratch register. The cycle must be found by hitting the root of the
// depth-first search.
void BreakCycle(int index);
// After a cycle has been resolved, restore the value from the scratch
// register to its proper destination.
void RestoreValue();
// Emit a move and remove it from the move graph.
void EmitMove(int index);
// Emit a move from one stack slot to another.
void EmitStackSlotMove(int index) {
masm_.StackSlotMove(moves_[index].source(), moves_[index].destination());
}
// Verify the move list before performing moves.
void Verify();
// Registers used to solve cycles.
const Register& SavedValueRegister() {
DCHECK(!masm_.ScratchRegister().IsAllocatable());
return masm_.ScratchRegister();
}
// The scratch register is used to break cycles and to store constant.
// These two methods switch from one mode to the other.
void AcquireSavedValueRegister() { masm_.AcquireScratchRegister(); }
void ReleaseSavedValueRegister() { masm_.ReleaseScratchRegister(); }
const FPRegister& SavedFPValueRegister() {
// We use the Crankshaft floating-point scratch register to break a cycle
// involving double values as the MacroAssembler will not need it for the
// operations performed by the gap resolver.
DCHECK(!crankshaft_fp_scratch.IsAllocatable());
return crankshaft_fp_scratch;
}
LCodeGen* cgen_;
DelayedGapMasm masm_;
// List of moves not yet resolved.
ZoneList<LMoveOperands> moves_;
int root_index_;
bool in_cycle_;
LOperand* saved_destination_;
};
} // namespace internal
} // namespace v8
#endif // V8_CRANKSHAFT_ARM64_LITHIUM_GAP_RESOLVER_ARM64_H_
|
