A study on decimal floating-point arithmetic unit through fused multiply-add architecture

自从电气和电子工程师协会（IEEE） 754二进制浮点标准于1985年被采用以来，每个微处理器和许多编程语言都指定了符合IEEE 754的浮点。最近，在许多商业应用程序中，包括金融分析、税收计算、电话计费、货币转换、基于internet的应用程序和电子商务，对十进制浮点（DFP）算术运算的需求有所增加。因此，DFP算术运算的规范最近被添加到IEEE浮点运算标准（IEEE754-2008）中。由于许多十进制小数（例如，0.1）不能精确地用二进制表示，因此需要以十进制格式存储数据并使用十进制算法处理数据。即使DFP算术软件消除了转换错误，DFP软件通常比在硬件中实现的等效二进制浮点（BFP）慢100到1000倍。因此，开发DFP算法单元的高效硬件实现是非常重要的。

Since the Institute of Electrical and Electronics Engineers (IEEE) 754 binary floating-point standard was adopted in 1985, every microprocessor and many programming languages have specified IEEE 754 compliant floating-point. Recently, there has been increased demand for decimal floating-point (DFP) arithmetic operations in many commercial applications, including financial analyses, tax calculations, phone billing, currency conversion, Internet-based applications, and e-commerce. Consequently, specifications for DFP arithmetic operations have recently been added to the IEEE Standard for Floating-Point Arithmetic (IEEE754-2008). Because many decimal fractional numbers (e.g., 0.1) cannot be exactly represented in binary, storing data in a decimal format and processing data using decimal arithmetic is desirable. Even if DFP arithmetic software eliminates conversion errors, DFP software is typically 100 to 1,000 times slower than equivalent binary floating-point (BFP) implemented in hardware. Therefore, it is very important to develop efficient hardware implementations of DFP arithmetic units.