2.1.3 Floats

 

CMU Common Lisp supports two floating point formats:  single-float and  double-float. These are implemented with IEEE single and double float arithmetic, respectively. short-float is a synonym for single-float, and long-float is a synonym for double-float. The initial value of  *read-default-float-format* is single-float.

Both single-float and double-float are represented with a pointer descriptor, so float operations can cause number consing. Number consing is greatly reduced if programs are written to allow the use of non-descriptor representations (see section 5.11.)

 
• 2.1.3.1 IEEE Special Values
• 2.1.3.2 Negative Zero
• 2.1.3.3 Denormalized Floats
• 2.1.3.4 Floating Point Exceptions
• 2.1.3.5 Floating Point Rounding Mode
  • Warning:
• 2.1.3.6 Accessing the Floating Point Modes