[Bug target/64008] [SH] sh4-linux configured compiler rejects -m4-nofpu

[olegendo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64008

Oleg Endo <olegendo at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |iwamatsu at nigauri dot org

--- Comment #2 from Oleg Endo <olegendo at gcc dot gnu.org> ---
I guess the SUPPORT_* macros are there to prevent scenarios like:

- SH4 machine with a GCC configured to produce SH4 code (with FPU, double
precision by default) without any -m options.

- No soft-fpu support code nor other multilib support code is present on the
SH4 machine

- Compiling a program with -m2 would produce SH2 code which might use soft-fpu
support code and various libgcc functions (e.g. dynamic shifts)

- Link error

Looking at config.gcc, it seems that specifying --enable-incomplete-targets
solves the problem, as it effectively enables all the target options.

Some related links:

https://lkml.org/lkml/2014/7/8/732
http://lists.openwall.net/linux-kernel/2014/07/08/1071

and a patch from somewhere else that seems related:

http://cgit.openembedded.org/openembedded/plain/recipes/gcc/gcc-4.5/sh4-multilib.patch

Maybe Nobuhiro has some comments regarding this issue...