frcpa
Instruction Type F
Format
(qp) frcpa.sf f1, p2 = f2, f3
Description
If PR qp is 0, PR p2 is cleared and f1 remains unchanged.
If PR qp is 1, the following will occur:
FR f1 is either set to an approximation (with a relative error < 2-8.886) of the reciprocal of FR f3, or to the IEEE-754 mandated quotient of FR f2/FR f3 &emdash; if either FR f2 or FR f3 is in the set {-Infinity, -0, Pseudo-zero, +0, +Infinity, NaN, Unsupported}.
If FR f1 is set to the approximation of the reciprocal of FR f3, then PR p2 is set to 1; otherwise, it is set to 0.
If FR f2 and FR f3 are such that the approximation of FR f3's reciprocal may cause the Newton-Raphson iterations to fail to produce the correct IEEE-754 result of FR f2/FR f3, then a Floating-point Exception fault for Software Assist occurs.
System software is expected to compute the IEEE-754 quotient (FR f2/FR f3), return the result in FR f1, and set PR p2 to 0.
If either FR f2 or FR f3 is a NaTVal, FR f1 is set to NaTVal instead of the computed result, and PR p2 is cleared.
For details, see Volume 3: Instruction Set Reference of the Intel(R) Itanium(R) Architecture Software Developer's Manual . For the latest updates on the instruction set information, go to the web site.