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// AsmJit - Machine code generation for C++
//
// * Official AsmJit Home Page: https://asmjit.com
// * Official Github Repository: https://github.com/asmjit/asmjit
//
// Copyright (c) 2008-2020 The AsmJit Authors
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would be
// appreciated but is not required.
// 2. Altered source versions must be plainly marked as such, and must not be
// misrepresented as being the original software.
// 3. This notice may not be removed or altered from any source distribution.
#ifndef ASMJIT_CORE_CONSTPOOL_H_INCLUDED
#define ASMJIT_CORE_CONSTPOOL_H_INCLUDED
#include "../core/support.h"
#include "../core/zone.h"
#include "../core/zonetree.h"
ASMJIT_BEGIN_NAMESPACE
//! \addtogroup asmjit_utilities
//! \{
// ============================================================================
// [asmjit::ConstPool]
// ============================================================================
//! Constant pool.
class ConstPool {
public:
ASMJIT_NONCOPYABLE(ConstPool)
//! Constant pool scope.
enum Scope : uint32_t {
//! Local constant, always embedded right after the current function.
kScopeLocal = 0,
//! Global constant, embedded at the end of the currently compiled code.
kScopeGlobal = 1
};
//! \cond INTERNAL
//! Index of a given size in const-pool table.
enum Index : uint32_t {
kIndex1 = 0,
kIndex2 = 1,
kIndex4 = 2,
kIndex8 = 3,
kIndex16 = 4,
kIndex32 = 5,
kIndexCount = 6
};
//! Zone-allocated const-pool gap created by two differently aligned constants.
struct Gap {
//! Pointer to the next gap
Gap* _next;
//! Offset of the gap.
size_t _offset;
//! Remaining bytes of the gap (basically a gap size).
size_t _size;
};
//! Zone-allocated const-pool node.
class Node : public ZoneTreeNodeT<Node> {
public:
ASMJIT_NONCOPYABLE(Node)
//! If this constant is shared with another.
uint32_t _shared : 1;
//! Data offset from the beginning of the pool.
uint32_t _offset;
inline Node(size_t offset, bool shared) noexcept
: ZoneTreeNodeT<Node>(),
_shared(shared),
_offset(uint32_t(offset)) {}
inline void* data() const noexcept {
return static_cast<void*>(const_cast<ConstPool::Node*>(this) + 1);
}
};
//! Data comparer used internally.
class Compare {
public:
size_t _dataSize;
inline Compare(size_t dataSize) noexcept
: _dataSize(dataSize) {}
inline int operator()(const Node& a, const Node& b) const noexcept {
return ::memcmp(a.data(), b.data(), _dataSize);
}
inline int operator()(const Node& a, const void* data) const noexcept {
return ::memcmp(a.data(), data, _dataSize);
}
};
//! Zone-allocated const-pool tree.
struct Tree {
//! RB tree.
ZoneTree<Node> _tree;
//! Size of the tree (number of nodes).
size_t _size;
//! Size of the data.
size_t _dataSize;
inline explicit Tree(size_t dataSize = 0) noexcept
: _tree(),
_size(0),
_dataSize(dataSize) {}
inline void reset() noexcept {
_tree.reset();
_size = 0;
}
inline bool empty() const noexcept { return _size == 0; }
inline size_t size() const noexcept { return _size; }
inline void setDataSize(size_t dataSize) noexcept {
ASMJIT_ASSERT(empty());
_dataSize = dataSize;
}
inline Node* get(const void* data) noexcept {
Compare cmp(_dataSize);
return _tree.get(data, cmp);
}
inline void insert(Node* node) noexcept {
Compare cmp(_dataSize);
_tree.insert(node, cmp);
_size++;
}
template<typename Visitor>
inline void forEach(Visitor& visitor) const noexcept {
Node* node = _tree.root();
if (!node) return;
Node* stack[Globals::kMaxTreeHeight];
size_t top = 0;
for (;;) {
Node* left = node->left();
if (left != nullptr) {
ASMJIT_ASSERT(top != Globals::kMaxTreeHeight);
stack[top++] = node;
node = left;
continue;
}
for (;;) {
visitor(node);
node = node->right();
if (node != nullptr)
break;
if (top == 0)
return;
node = stack[--top];
}
}
}
static inline Node* _newNode(Zone* zone, const void* data, size_t size, size_t offset, bool shared) noexcept {
Node* node = zone->allocT<Node>(sizeof(Node) + size);
if (ASMJIT_UNLIKELY(!node)) return nullptr;
node = new(node) Node(offset, shared);
memcpy(node->data(), data, size);
return node;
}
};
//! \endcond
//! Zone allocator.
Zone* _zone;
//! Tree per size.
Tree _tree[kIndexCount];
//! Gaps per size.
Gap* _gaps[kIndexCount];
//! Gaps pool
Gap* _gapPool;
//! Size of the pool (in bytes).
size_t _size;
//! Required pool alignment.
size_t _alignment;
//! \name Construction & Destruction
//! \{
ASMJIT_API ConstPool(Zone* zone) noexcept;
ASMJIT_API ~ConstPool() noexcept;
ASMJIT_API void reset(Zone* zone) noexcept;
//! \}
//! \name Accessors
//! \{
//! Tests whether the constant-pool is empty.
inline bool empty() const noexcept { return _size == 0; }
//! Returns the size of the constant-pool in bytes.
inline size_t size() const noexcept { return _size; }
//! Returns minimum alignment.
inline size_t alignment() const noexcept { return _alignment; }
//! \}
//! \name Utilities
//! \{
//! Adds a constant to the constant pool.
//!
//! The constant must have known size, which is 1, 2, 4, 8, 16 or 32 bytes.
//! The constant is added to the pool only if it doesn't not exist, otherwise
//! cached value is returned.
//!
//! AsmJit is able to subdivide added constants, so for example if you add
//! 8-byte constant 0x1122334455667788 it will create the following slots:
//!
//! 8-byte: 0x1122334455667788
//! 4-byte: 0x11223344, 0x55667788
//!
//! The reason is that when combining MMX/SSE/AVX code some patterns are used
//! frequently. However, AsmJit is not able to reallocate a constant that has
//! been already added. For example if you try to add 4-byte constant and then
//! 8-byte constant having the same 4-byte pattern as the previous one, two
//! independent slots will be generated by the pool.
ASMJIT_API Error add(const void* data, size_t size, size_t& dstOffset) noexcept;
//! Fills the destination with the content of this constant pool.
ASMJIT_API void fill(void* dst) const noexcept;
};
//! \}
ASMJIT_END_NAMESPACE
#endif // ASMJIT_CORE_CONSTPOOL_H_INCLUDED