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Libraries and Floating Point Support Guide

Preface The ARM C and C++ Libraries The ARM C Micro-library Floating-point Support About floating-point support The software floating-point library, fplib Calling fplib routines fplib arithmetic on numbers in a particular format fplib conversions between floats, long longs, doub fplib comparisons between floats and doubles fplib C99 functions Controlling the ARM floating-point environment Floating-point functions for compatibility with Mi C99-compatible functions for controlling the ARM f C99 rounding mode and floating-point exception mac Exception flag handling Functions for handling rounding modes Functions for saving and restoring the whole float Functions for temporarily disabling exceptions ARM floating-point compiler extensions to the C99 Writing a custom exception trap handler Example of a custom exception handler Exception trap handling by signals mathlib double and single-precision floating-point IEEE 754 arithmetic Basic data types for IEEE 754 arithmetic Single precision data type for IEEE 754 arithmetic Double precision data type for IEEE 754 arithmetic Sample single precision floating-point values for Sample double precision floating-point values for IEEE 754 arithmetic and rounding Exceptions arising from IEEE 754 floating-point ar Exception types recognized by the ARM floating-poi Using the Vector Floating-Point (VFP) support libr The C and C++ Library Functions reference Floating-point Support Functions Reference

About floating-point support

3.1 About floating-point support

The ARM® floating-point environment is an implementation of the IEEE 754-1985 standard for binary floating-point arithmetic.

An ARM system might have:
  • A VFP coprocessor.
  • No floating-point hardware.
If you compile for a system with a hardware VFP coprocessor, the ARM compiler makes use of it. If you compile for a system without a coprocessor, the compiler implements the computations in software. For example, the compiler option --fpu=vfp selects a hardware VFP coprocessor and the option --fpu=softvfp specifies that arithmetic operations are to be performed in software, without the use of any coprocessor instructions.
Related information
Non-ConfidentialPDF file icon PDF versionARM DUI0378H
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