constant_pool: Implement a constant pool

src/backend_x64/constant_pool.cpp

@@ -0,0 +1,36 @@
+/* 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_x64/block_of_code.h"
+#include "backend_x64/constant_pool.h"
+#include "common/assert.h"
+
+namespace Dynarmic {
+namespace BackendX64 {
+
+ConstantPool::ConstantPool(BlockOfCode* code, size_t size) : code(code), pool_size(size) {
+    code->int3();
+    code->align(align_size);
+    pool_begin = reinterpret_cast<u8*>(code->AllocateFromCodeSpace(size));
+    std::memset(pool_begin, 0, size);
+    current_pool_ptr = pool_begin;
+}
+
+Xbyak::Address ConstantPool::GetConstant(u64 constant) {
+    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, &constant, sizeof(u64));
+        iter = constant_info.emplace(constant, current_pool_ptr).first;
+        current_pool_ptr += align_size;
+    }
+    return code->xword[code->rip + iter->second];
+}
+
+} // namespace BackendX64
+} // namespace Dynarmic