SH/M32R T-Engine Home Page

< Question >

When the T-Kernel for the FPU-incorporating microcontroller (SH7751R or SH7760) is built with GCC4.0.0, etc., a compile error occurs.

< Answer >

Applicable compilers: GCC4.0.0, GCC4.0.2 and GCC4.1

When the T-Kernel for the FPU-incorporating microcontroller (SH7751R or SH7760) is built using GNU tools published at the present Home Page, the compile error shown below occurs.

cc1: error: invalid option ‘no-implicit-fp’

The default compile option of the SH7751R and SH7760 T-Kernel is as follows:

_CPUTYPE_FLAGS = -m4 -mno-implicit-fp

Of this, -mno-implicit-fp is an option to specify the library to be referenced, and is an option specific to the GNU environment supplied with the T-Engine development kit.
When you are using the GNU tools published at the present Home Page, please change it to one of the following options:

　-m4-nofpu　　　　　　　　　Generate SH4 FPU-less code
　-m4-single　　　　　　　　　Generate default single-precision SH4 code
　-m4-single-only　　　　　　Generate only single-precision SH4 code

<Example for the SH7751R: -m4-nofpu used>
File: tkernel_source/etc/sysdepend/std_sh7751r/makerules.sysdepend

# ----- T-Engine/SH7751R(SH4) -------------------------------------

# GCC environment
TARGET_ARCH =

# target type
#_CPUTYPE_FLAGS = -m4 -mno-implicit-fp 　← Before correction
_CPUTYPE_FLAGS = -m4-nofpu 　　　　　　　　　← After correction
_TE_SYSTEM_NAME_ = _STD_SH7751R_

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