RealView Compilation Tools Compiler Reference Guide - ARM ...

Compiler-specific Features
Return value
The __strex intrinsic returns:
0 if the STREX instruction succeeds
1 if the STREX instruction is locked out.
Errors
The compiler does not recognize the __strex intrinsic when compiling for a target that
does not support the STREX instruction. The compiler generates either a warning or an
error in this case.
The __strex intrinsic does not support access to doubleword data. The compiler
generates an error if you specify an access width that is not supported.
Example
int foo(void)
{
int loc=0xff;
}
return(!__strex(0x20, (volatile char *)loc));
Compiling this code with the command-line option --cpu=6k produces
||foo|| PROC
MOV
MOV
STREXB
RSBS
MOVCC
BX
ENDP
r0,#0xff
r2,#0x20
r1,r2,[r0]
r0,r1,#1
r0,#0
lr
See also
• __ldrex on page 4-75
• LDREX and STREX on page 4-35 in the Assembler Guide.
4.7.40 __strt
This intrinsic inserts an assembly language instruction of the form STR{size}T into the
instruction stream generated by the compiler. It enables you to store data to memory in
your C or C++ code using an STRT instruction.
4-90 Copyright © 2007, 2010 ARM Limited. All rights reserved. ARM DUI 0348A
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