Title :
Some functions computable with a fused-mac
Author :
Boldo, Sylvie ; Muller, Jean-Michel
Author_Institution :
Lab. LIP, Ecole Normale Superieure, Lyon, France
Abstract :
The fused multiply accumulate instruction (fused-mac) that is available on some current processors such as the Power PC or the Itanium eases some calculations. We give examples of some floating-point functions (such as ulp(x) or Nextafter(x, y)), or some useful tests, that are easily computable using a fused-mac. Then, we show that, with rounding to the nearest, the error of a fused-mac instruction is exactly representable as the sum of two floating-point numbers. We give an algorithm that computes that error.
Keywords :
floating point arithmetic; function evaluation; instruction sets; parallel processing; roundoff errors; Power PC; floating-point functions; floating-point numbers; fused multiply accumulate instruction; fused-mac instruction; Computer aided instruction; Error analysis; Floating-point arithmetic; Functional programming; Linear algebra; Polynomials; Portable computers; Roundoff errors; Software performance; Testing;
Conference_Titel :
Computer Arithmetic, 2005. ARITH-17 2005. 17th IEEE Symposium on
Print_ISBN :
0-7695-2366-8
DOI :
10.1109/ARITH.2005.39