提出利用雙倍暫存器，使得編譯器或程式設計師可以使用更多的暫存器提高程式的效率，更重要的是此指令格式不會增加額外的位元使指令長度增加。利用這方法我們可以將 ARM 微處理器中暫存器的數目增為原本的 2 倍，讓 32 位元的指令可以使用的暫存器從 16 個增加到 32 個，使得編譯器或程式設計師可以使用 32 個暫存器來存放變數或計算結果，提高程式的效率。

雖然藉由增加暫存器，提升程式效率是很普遍的方式，但如果不增加額外的位元在指令中處理所增加的暫存器數目，那勢必在程式中必須替換 ARM 處理器原有的功能，使暫存器增加。而在本篇論文中我們提出兩個方法，希望保留 ARM 原有的功能並且增加一倍的暫存器數目，進而使程式效率提升。

Proposed use of the double registers, the compiler or the programmer can use more registers to improve the efficiency of the program. It is important the instruction format does not add an extra bit instruction length increases. This method can be ARM micro processor registers the number increased to 2-fold, 32-bit instruction register that can be used from 16 to 32, making the compiler or the programmer 32 registers for storing variables or calculated results, improve the efficiency of the program.

By additional registers, improve program efficiency is very common, but if you do not increase the number of extra bits in the instruction register to handle the increased, it is bound to replace the ARM processor in the program must be original function, so that register increases. In this paper, we propose two methods, and want to preserve the original features of the ARM and doubling the register number, and thus make the program efficiency.

論文摘要 1
誌謝 2
第一章 序論 6
1.1 研究背景 6
1.2 研究動機 6
1.3 研究目的 8
1.4 研究方法 8
1.5 論文架構 9
第二章 文獻回顧 10
2.1 微處理器硬體架構 10
2.2 增加暫存器數目相關 13
2.2.1 Change Register Bank 13
2.2.2 Trading conditional execution 14
2.2.3 指令編碼方式 15
第三章 方法 21
3.1 概念 21
3.2 Doubling the number of registers with IT Instruction 23
3.2.1 GCC retargeted 24
3.2.2 Thumb2 IT instruction 25
3.2.3 GCC 相關部分 28
3.3 Doubling the number of registers with mode change 30
3.3.1 兩種模式架構 30
3.3.2 切換模式策略 33
3.3.3 Compiler - IRA 35
3.3.4 選擇最佳模式 37
第四章 實驗結果 39
4.1 實驗平台 39
4.2 效能評估 40
第五章 結論 45
5.1 結論 45
5.2 未來展望 45
參考文獻 46

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