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Default:
The xgcc C compiler searches sub-programs in the current directory and the PATH directory.
-I<directory>
Specify include file directory
Function:
Description: This option is used to specify the directory that contains the files included in the C source.
Input <directory> immediately after -I. Multiple directories can be specified. In this case, input
as many instances of -I<directory> as necessary. The include files are searched in the order they
appear in the command line.
If the directory is registered in environment variable C_INCLUDE_PATH, the -I option is
unnecessary.
File search is performed in order of priorities, i.e., current directory, - I option, and
C_INCLUDE_PATH in that order.
Default:
The xgcc C compiler searches include files in the current directory and the C_INCLUDE_PATH
directory.
-D<macro name>[=<replacement character>]
Define macro name
Function:
Description: This option functions in the same way as #define. If there is =<replacement character>
specified, define its value in the macro. If not specified, the value of the macro is set to 1.
Input <macro name>[=<replacement character>] immediately after -D. Multiple macro names
can be specified. In this case, input as many instances of -D<macro name>[=<replacement char-
acter>] as necessary.
* About automatic generation of macro names
The macro names listed below are automatically defined during compilation. These macro
names can be referenced from any source file. Note, however, that the same macro names
cannot be used for macro definitions in the user program.
Macro name
__c17
__INT__
__POINTER24
__POINTER16
__LONG_OFFSET
__SHORT_OFFSET Indicates that the source was compiled with the -mshort-offset
-O0,-O,-O3
Optimization
Function:
Description: Specify one of the switches, then optimize.
The code generated is optimized by prioritizing speed and size. When the -O3 option is specified,
optimization prioritizes speed only.
The larger the number following "-O", the stronger the optimization applied. However, keep
in mind that large values may generate issues, such as failure to output parts of the debug
information.
Reduce this value if the optimization cannot be executed properly. Register interlocks are ignored
during optimization. Since the -O3 option is designed to optimize speed, size in certain cases can
grow larger than that resulting from the use of the -O option. In ordinary cases, we recommend
using -O when compiling.
Basic makefiles created by the IDE use the -O option as the startup command for xgcc C compiler.
The characteristics of each option are described below.
-O0
No optimization performed.
An area is secured in the stack even if an unused local variable is declared.
S5U1C17001C ManUal
(C COMPilEr PaCkagE fOr S1C17 faMily) (Ver. 1.5.0)
Contents
Indicates that the source was compiled for S1C17 processors.
Indicates the data size of int type variables (16).
Indicates that the source was compiled without the -mpointer16
compile option specified.
Indicates that the source was compiled with the -mpointer16 com-
pile option specified.
Indicates that the source was compiled without the -mshort-offset
compile option specified.
compile option specified.
EPSOn
6 C COMPilEr
6
Compiler
6-3
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