tests/qtest: Add npcm7xx timer test
[qemu.git] / disas / libvixl / vixl / code-buffer.h
1 // Copyright 2014, ARM Limited
2 // All rights reserved.
3 //
4 // Redistribution and use in source and binary forms, with or without
5 // modification, are permitted provided that the following conditions are met:
6 //
7 // * Redistributions of source code must retain the above copyright notice,
8 // this list of conditions and the following disclaimer.
9 // * Redistributions in binary form must reproduce the above copyright notice,
10 // this list of conditions and the following disclaimer in the documentation
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12 // * Neither the name of ARM Limited nor the names of its contributors may be
13 // used to endorse or promote products derived from this software without
14 // specific prior written permission.
15 //
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
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26
27 #ifndef VIXL_CODE_BUFFER_H
28 #define VIXL_CODE_BUFFER_H
29
30 #include <string.h>
31 #include "vixl/globals.h"
32
33 namespace vixl {
34
35 class CodeBuffer {
36 public:
37 explicit CodeBuffer(size_t capacity = 4 * KBytes);
38 CodeBuffer(void* buffer, size_t capacity);
39 ~CodeBuffer();
40
41 void Reset();
42
43 ptrdiff_t OffsetFrom(ptrdiff_t offset) const {
44 ptrdiff_t cursor_offset = cursor_ - buffer_;
45 VIXL_ASSERT((offset >= 0) && (offset <= cursor_offset));
46 return cursor_offset - offset;
47 }
48
49 ptrdiff_t CursorOffset() const {
50 return OffsetFrom(0);
51 }
52
53 template <typename T>
54 T GetOffsetAddress(ptrdiff_t offset) const {
55 VIXL_ASSERT((offset >= 0) && (offset <= (cursor_ - buffer_)));
56 return reinterpret_cast<T>(buffer_ + offset);
57 }
58
59 size_t RemainingBytes() const {
60 VIXL_ASSERT((cursor_ >= buffer_) && (cursor_ <= (buffer_ + capacity_)));
61 return (buffer_ + capacity_) - cursor_;
62 }
63
64 // A code buffer can emit:
65 // * 32-bit data: instruction and constant.
66 // * 64-bit data: constant.
67 // * string: debug info.
68 void Emit32(uint32_t data) { Emit(data); }
69
70 void Emit64(uint64_t data) { Emit(data); }
71
72 void EmitString(const char* string);
73
74 // Align to kInstructionSize.
75 void Align();
76
77 size_t capacity() const { return capacity_; }
78
79 bool IsManaged() const { return managed_; }
80
81 void Grow(size_t new_capacity);
82
83 bool IsDirty() const { return dirty_; }
84
85 void SetClean() { dirty_ = false; }
86
87 private:
88 template <typename T>
89 void Emit(T value) {
90 VIXL_ASSERT(RemainingBytes() >= sizeof(value));
91 dirty_ = true;
92 memcpy(cursor_, &value, sizeof(value));
93 cursor_ += sizeof(value);
94 }
95
96 // Backing store of the buffer.
97 byte* buffer_;
98 // If true the backing store is allocated and deallocated by the buffer. The
99 // backing store can then grow on demand. If false the backing store is
100 // provided by the user and cannot be resized internally.
101 bool managed_;
102 // Pointer to the next location to be written.
103 byte* cursor_;
104 // True if there has been any write since the buffer was created or cleaned.
105 bool dirty_;
106 // Capacity in bytes of the backing store.
107 size_t capacity_;
108 };
109
110 } // namespace vixl
111
112 #endif // VIXL_CODE_BUFFER_H
113