20.5 Note Concerning system.context
The recommendation setting of system.context is indicated from now on. If other than recommended setting is specified, the RI600PX performance may be slightly deteriorated, compared to the recommended settings case.
1 ) When using MCU that incorporates FPU and DSP (accumulator)
Corresponding MCUs: RX600 series, etc.
Corresponding MCUs: RX600 series, etc.
2 ) When using MCU that does not incorporate FPU, but incorporates DSP (accumulator)
Corresponding MCUs: RX200 series, etc.
Corresponding MCUs: RX200 series, etc.
3 ) When using MCU that incorporates FPU, but does not incorporate DSP (accumulator)
Corresponding MCUs: MCUs that corresponds to this doesn't exist at the time of making of this manual.
Corresponding MCUs: MCUs that corresponds to this doesn't exist at the time of making of this manual.
4 ) When using MCU that incorporate neither FPU nor DSP (accumulator)
Corresponding MCUs: MCUs that corresponds to this doesn't exist at the time of making of this manual.
Corresponding MCUs: MCUs that corresponds to this doesn't exist at the time of making of this manual.
Note The compiler outputs floating-point arithmetic instructions only when the -fpu option is specified. If the -chkfpu option is specified in the assembler, the floating-point arithmetic instructions written in a program are detected as warning.
In no case does the compiler output the DSP function instructions. If the -chkdsp option is specified in the assembler, the DSP function instructions written in a program are detected as warning.
In no case does the compiler output the DSP function instructions. If the -chkdsp option is specified in the assembler, the DSP function instructions written in a program are detected as warning.
n system.context, by selecting one of choices "MIN," "MIN, ACC", "MIN, FPSW," or "MIN, ACC, FPSW," it is possible to configure the registers so that R8- R13 registers will not be saved as task context. This results in an increased processing speed.
Note, however, that such a setting of system.context is permitted in only the case where all of R8 - R13 registers are specified to be used by the compiler options "-fint_register", "-base" and "-pid".