RealView Compilation Tools Compiler Reference Guide - ARM ...

Compiler-specific Features
MOV r2,#0x100
LDRBT r0,[r2],#0
ORR r0,r1,r0,LSL #8
BX lr
ENDP
See also
• --thumb on page 2-86
• LDR and STR (User mode) on page 4-18 in the Assembler Guide.
4.7.22 __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.
Syntax
void __memory_changed(void)
See also
• __force_stores on page 4-74
• __schedule_barrier on page 4-85.
4.7.23 __nop
This intrinsic inserts a NOP instruction or an equivalent code sequence into the
instruction stream generated by the compiler. One NOP instruction is generated for each
__nop intrinsic in the source.
The compiler does not optimize-away the NOP instructions, except for normal
unreachable-code elimination. The __nop intrinsic also acts as a barrier for instruction
scheduling in the compiler. That is, instructions are not moved from one side of the NOP
to the other as a result of optimization.
Note
You can use the __schedule_barrier intrinsic to insert a scheduling barrier without
generating a NOP instruction.
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