HP-UX Floating-Point Guide

Chapter 2 47
Floating-Point Principles and the IEEE Standard for Binary Floating-Point Arithmetic
Floating-Point Formats
Table 2-5 Operations With Zero
NOTE In multiplication and division operations with positive and negative zero
operands, the sign is determined by the usual arithmetic rules.
The result of some operations is dependent on the rounding mode. The
table assumes that the rounding is set to the default round-to-nearest
mode. See “Inexact Result (Rounding)” on page 53.
Complex Data Types
The IEEE standard does not address the topic of complex arithmetic, so
it does not define complex data type formats. HP Fortran 90 and HP
FORTRAN/9000 implement two complex data types, single-precision
complex (COMPLEX, COMPLEX(KIND=4)) and double-precision complex
(COMPLEX(KIND=8)). The COMPLEX type consists of a real and an
imaginary component, each of which is a single-precision IEEE operand.
The COMPLEX(KIND=8) data type is analogous to COMPLEX, except that
Operand Operator Operand Result
+Zero .EQ. −Zero True
+Zero
−Zero
+Zero
−Zero
+
+
+
+
+Zero
−Zero
−Zero
+Zero
+Zero
−Zero
+Zero (in round-to-nearest
mode)
+Zero (in round-to-nearest
mode)
+Zero
−Zero
+Zero
−Zero
−
−
−
−
+Zero
−Zero
−Zero
+Zero
+Zero (in round-to-nearest
mode)
+Zero (in round-to-nearest
mode)
+Zero
−Zero
+Zero * −Zero −Zero
±Infinity
±Finite Value
/
/
±Zero
±Zero
±Infinity
±Infinity
−Zero sqrt() −Zero