GENERAL: What Is a Floating-point Operation?

Information in this article applies to:

• C166 Version 4.05
• C251 Version 2.14
• C51 Version 6.01

QUESTION

What, in plain English, is a floating-point operation and how does it work within the computer system?

ANSWER

In C, an operation is the effect of an operator on an expression. Specific to floating-point numbers, a floating-point operation is any mathematical operation (such as +, -, *, /) or assignment that involves floating-point numbers (as opposed to binary integer operations).

Floating-point numbers have decimal points in them. The number 2.0 is a floating-point number because it has a decimal in it. The number 2 (without a decimal point) is a binary integer.

Floating-point operations involve floating-point numbers and typically take longer to execute than simple binary integer operations. For this reason, most embedded applications avoid wide-spread usage of floating-point math in favor of faster, smaller integer operations.

MORE INFORMATION

• Refer to the IEEE Standard 754 Floating Point Numbers for more details.
• Refer to Floating-point Numbers in the Cx51 User's Guide.

SEE ALSO

• C51: Support for Floating-point Numbers
• GENERAL: Floating-point Standard
• GENERAL: Converting Floating-point Number to Integer
• GENERAL: byte-wise access to float variables
• GENERAL: Precision of printf %f Format String

Last Reviewed: Thursday, February 25, 2021