Atmel CAVR-4 Manual De Usuario

CAVR-4

Part 2. Compiler reference

The following example—in which 

%1

 is an operating system variable containing the 

name of the source file—will give duplicate name errors from the linker:

preproc %1.c temp.c

; preprocess source,  

 

; generating temp.c

iccavr temp.c 

; module name is  

 

; always 'temp'

To avoid this, use 

--module_name=name

 to retain the original name:

preproc %1.c temp.c

; preprocess source,  

 

; generating temp.c

iccavr temp.c --module_name=%1

; use original source 

 

; name as module name

Note: In this example, 

preproc

 is an external utility.

To set the equivalent option in IAR Embedded Workbench, select 
Project>Options>C/C++ Compiler>Output.

--no_clustering

--no_clustering

This option will disable clustering of variables. Clustered variables may be accessed 
through a common base pointer which will, in most cases, reduce the size of the 
generated code.

--no_code_motion

--no_code_motion 

Use this option to disable optimizations that move code. These optimizations, which are 
performed at optimization levels 6 and 9, normally reduce code size and execution time. 
However, the resulting code may be difficult to debug.

Note: This option has no effect at optimization levels below 6.

To set the equivalent option in IAR Embedded Workbench, select 
Project>Options>C/C++ Compiler>Code.

--no_cross_call

--no_cross_call

Use this option to disable the cross-call optimization. This is highly recommended if 
your target processor has a hardware stack or a small internal return stack segment, 

RSTACK

, since this option reduces the usage of 

RSTACK

. 

This optimization is performed at size optimization, level 7–9. Note that, although it can 
drastically reduce the code size, this option increases the execution time.