公开(公告)号：WO2016207595A1

公开(公告)日：2016-12-29

申请号：PCT/GB2016/051421

申请日：2016-05-17

Applicant: ARM LIMITED

Inventor： STEWART, Daryl John ,  GROCUTT, Thomas Christopher

IPC: G06F7/485 ,  G06F7/499 ,  G06F7/544

CPC classification number: G06F7/485 ,  G06F5/012 ,  G06F7/49905 ,  G06F7/4991 ,  G06F7/49942 ,  G06F7/5443

Abstract: An apparatus and method are provided for processing floating point values using an intermediate representation which has significand, exponent and shadow sections. A less significant portion of the exponent of the floating point value defines a range of positions within the significand section where the representation of the significand is to be held. The exponent section holds a representation of a more significant portion of the exponent indicating a selected window of multiple contiguous windows spanning a value range of a format of the floating point value. A first portion of the significand section corresponds to the selected window and a second portion corresponds to an overlap into a further window which is adjacent to and lower in the value range. The shadow section holds values for populating the second portion of the significand section when the representation of the significand of the floating point value is moved to a higher window which is adjacent to and higher in the value range than the selected window. The shadow section allows the selected window to be shifted, such that the summation of multiple values produces the same result independent of the order in which the values are summed.

Abstract translation: 提供了一种使用具有有效数，指数和阴影部分的中间表示来处理浮点值的装置和方法。 浮点值的指数的不太重要部分定义要保持有效数的表示的有效位数段内的位置范围。 指数部分保持指数的更重要部分的表示，指示跨越浮点值格式的值范围的多个连续窗口的选定窗口。 有效部分的第一部分对应于所选择的窗口，第二部分对应于与值范围相邻且较低的另一窗口的重叠。 当浮点值的有效位数的表示被移动到与所选择的窗口相邻且在值范围内的较高窗口时，阴影部分保持用于填充有效部分的第二部分的值。 阴影部分允许所选择的窗口被移动，使得多个值的求和产生相同的结果，而不依赖于求和值的顺序。