RealView Compilation Tools Compiler Reference Guide - ARM ...

Compiler-specific Features
Note
This is used in the offsetof macro.
Syntax
__INTADDR(expr)
Where:
expr
is an integral constant expression.
Return value
__INTADDR__(expr) returns an integer constant equivalent to expr.
See also
• Restrictions on embedded assembly on page 6-19 in the Compiler User Guide.
4.1.10 __irq
The __irq keyword enables a C or C++ function to be used as an interrupt routine.
__irq is a function qualifier. It affects the type of the function.
Restrictions
All corrupted registers except floating-point registers are preserved, not only those that
are normally preserved under the AAPCS. The default AAPCS mode must be used.
The function exits by setting the program counter to lr-4 and the CPSR to the value in
SPSR. No arguments or return values can be used with __irq functions.
Note
When compiling for Thumb using the --thumb option or #pragma thumb, any functions
specified as __irq are compiled for ARM.
See also
• --thumb on page 2-86
• #pragma thumb on page 4-62
• Chapter 6 Handling Processor Exceptions in the Developer Guide.
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