RealView Compilation Tools Compiler Reference Guide - ARM ...

Compiler-specific Features
Note
The __fabs intrinsic is an analogue of the standard C library function fabs. It differs
from the standard library function in that a call to __fabs is guaranteed to be compiled
into a single, inline, machine instruction on an ARM architecture-based processor
equipped with a VFP coprocessor.
Syntax
double __fabs(double val)
Where:
val
is a double-precision floating-point value.
Return value
The __fabs intrinsic returns the absolute value of val as a double.
See also
• __fabsf
• VABS, VNEG, and VSQRT on page 5-89 in the Assembler Guide.
4.7.18 __fabsf
This intrinsic is a single-precision version of the __fabs intrinsic. It is functionally
equivalent to __fabs, except that:
• it takes an argument of type float instead of an argument of type double
• it returns a float value instead of a double value.
See also
• __fabs on page 4-73
• V{Q}ABS and V{Q}NEG on page 5-52 in the Assembler Guide.
4.7.19 __force_stores
This intrinsic causes all variables that are visible outside the current function, such as
variables that have pointers to them passed into or out of the function, to be written back
to memory if they have been changed.
This intrinsic also acts as a scheduling barrier.
4-74 Copyright © 2007, 2010 ARM Limited. All rights reserved. ARM DUI 0348A
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