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Compiler-specific Features
Return value
The __ldrt intrinsic returns the data loaded from the memory address pointed to by ptr.
Errors
The compiler does not recognize the __ldrt intrinsic when compiling for a target that
does not support the LDRT instruction. The compiler generates either a warning or an
error in this case.
The __ldrt 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 __ldrt((const volatile int *)loc);
}
Compiling this code with the default options produces:
||foo|| PROC
MOV r0,#0xff
LDRBT r1,[r0],#0
MOV r2,#0x100
LDRBT r0,[r2],#0
ORR r0,r1,r0,LSL #8
BX lr
ENDP
See also
• --thumb on page 2-122
• LDR and STR (User mode) on page 4-18 in the Assembler Guide.
4.7.17 __memory_changed
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, and then to be read back from memory.
This intrinsic also acts as a scheduling barrier.
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