backend/a64: Port const pool

src/backend/A64/constant_pool.cpp

@@ -0,0 +1,38 @@
+/* This file is part of the dynarmic project.
+ * Copyright (c) 2016 MerryMage
+ * This software may be used and distributed according to the terms of the GNU
+ * General Public License version 2 or any later version.
+ */
+
+#include <cstring>
+
+#include "backend/A64/block_of_code.h"
+#include "backend/A64/constant_pool.h"
+#include "common/assert.h"
+
+namespace Dynarmic::BackendA64 {
+
+ConstantPool::ConstantPool(BlockOfCode& code, size_t size) : code(code), pool_size(size) {}
+
+void ConstantPool::AllocatePool() {
+    code.BRK(0);
+    pool_begin = const_cast<u8*>(code.AlignCode16());
+    code.AllocateFromCodeSpace(pool_size);
+    current_pool_ptr = pool_begin;
+    ASSERT(code.GetCodePtr() - pool_begin == static_cast<u32>(pool_size));
+}
+
+void* ConstantPool::GetConstant(u64 lower, u64 upper) {
+    const auto constant = std::make_tuple(lower, upper);
+    auto iter = constant_info.find(constant);
+    if (iter == constant_info.end()) {
+        ASSERT(static_cast<size_t>(current_pool_ptr - pool_begin) < pool_size);
+        std::memcpy(current_pool_ptr, &lower, sizeof(u64));
+        std::memcpy(current_pool_ptr + sizeof(u64), &upper, sizeof(u64));
+        iter = constant_info.emplace(constant, current_pool_ptr).first;
+        current_pool_ptr += align_size;
+    }
+    return iter->second;
+}
+
+} // namespace Dynarmic::BackendX64

src/backend/A64/constant_pool.h

@@ -0,0 +1,40 @@
+/* This file is part of the dynarmic project.
+ * Copyright (c) 2016 MerryMage
+ * This software may be used and distributed according to the terms of the GNU
+ * General Public License version 2 or any later version.
+ */
+
+#pragma once
+
+#include <map>
+
+#include "common/common_types.h"
+
+namespace Dynarmic::BackendA64 {
+
+class BlockOfCode;
+
+/// ConstantPool allocates a block of memory from BlockOfCode.
+/// It places constants into this block of memory, returning the address
+/// of the memory location where the constant is placed. If the constant
+/// already exists, its memory location is reused.
+class ConstantPool final {
+public:
+    ConstantPool(BlockOfCode& code, size_t size);
+
+    void AllocatePool();
+
+    void* GetConstant(u64 lower, u64 upper = 0);
+
+private:
+    static constexpr size_t align_size = 16; // bytes
+
+    std::map<std::tuple<u64, u64>, void*> constant_info;
+
+    BlockOfCode& code;
+    size_t pool_size;
+    u8* pool_begin;
+    u8* current_pool_ptr;
+};
+
+} // namespace Dynarmic::BackendA64