Hi all, I need some help about assigning two structures.
The simple Function
void CopyStruct(struct A *sSrc, struct A *sDst) { *sDst = *sSrc; }
is translated to
; Variable 'sDst' assigned to Register 'R10/R11' ; Variable 'sSrc' assigned to Register 'R8/R9' 0010 F06A MOV R6,R10 0012 F048 MOV R4,R8 0014 F07B MOV R7,R11 0016 F059 MOV R5,R9 0018 E6F23600 MOV R2,#036H 001C DA000000 E CALLS SEG (?C_WCPYFF),?C_WCPYFF
How is the data copied? Where can I find the implementation of the library Function "C_WCPYFF"? (Keil C166 6.04a)
Thanks for your Help.
Regards, Marcus
"What about Data Integrity of larger Objects in Multitasking Environments?"
Even a simple assignment is not guaranteed to be atomic - so nothing special here.
"What about Performance in time-critical projects?"
If you have a time-critical project, why are you copying big structures around anyhow?
"Of course I could write my own Function, but the simple assignment is quite charming."
That's the trade-off: either write it yourself, and know what's going on, or go for convenience and delegate the control to the compiler. You can't have it both ways, I'm afraid.
Even a simple assignment is not guaranteed to be atomic - so nothing special here
What do you mean by that? In which cases can a 8 or 16 Bit assignment on a 16 Bit Platform like the XC be unsafe? Can you give me an example?
Thanks
"In which cases can a 8 or 16 Bit assignment on a 16 Bit Platform like the XC be unsafe"
I didn't say that!
All I said was, Even a simple assignment is not guaranteed to be atomic"
In fact, as you say, it probably will be safe for 8 or 16 bit assignments on a 16 Bit Platform like the XC - but that is a feature of the target environment, not a guarantee of the language. And what happens if the 16-bit value is not word-aligned...?