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Solving the generalized mask constraint for test generation of binary floating point add operation

✍ Scribed by Abraham Ziv; Laurent Fournier


Book ID
104325434
Publisher
Elsevier Science
Year
2003
Tongue
English
Weight
161 KB
Volume
291
Category
Article
ISSN
0304-3975

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✦ Synopsis


The mathematical problem discussed is important for generating test cases in order to debug oating point adders designs.

Floating point numbers are assumed to be written as strings of {0; 1} bits, in a format compatible with IEEE standard 754. A mask is a string of characters, composed of {'0', '1', 'x'}. A number and a mask are compatible if they have the same length and each numerical character of the mask ('0' or '1') is equal, numerically, to the bit of the number, in the same position. The problem discussed is: Given masks Ma, M b , Mc, of identical lengths, generate three oating point numbers a, b, c, which are compatible with the masks and satisfy c =round( a± b). If there are many solutions, choose one at random. A fast algorithm is given which solves the problem for all IEEE oating point data types and all rounding modes.