[Bug driver/83193] Help for invalid -march= options from cc1 omits -march=native on x86-64, arm. aarch64, output also inconsistent

[andrewm.roberts at sky dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83193

--- Comment #1 from Andrew Roberts <andrewm.roberts at sky dot com> ---
The same comments also apply to the -mcpu and -mtune options as well. Double
output on arm for -mcpu, and missing help for native.

also:

gcc -Q --help=target
used to document the allowable -mcpu/-mtune options, but now only documents the
allowable -mfpu/-mfpmath= options (across ARM, AARCH64 and X86-64). This was
really helpful.

And on aarch64 the -Q --help-target option doesn't properly display -march,
-mcpu -mtune, it displays -march=ARCH, -mcpu=CPU, -mtune=CPU, rather than
-march=, -mcpu=, -mtune= as other systems do.

AARCH64
/usr/local/gcc/bin/gcc -Q --help=target
The following options are target specific:
...  
  -march=ARCH                           armv8-a
...
  -mcpu=CPU
...
  -mtune=CPU

ARM
/usr/local/gcc/bin/gcc -Q --help=target
The following options are target specific:
...
  -march=                               armv7-a+fp
...
  -mcpu=
...
  -mtune=



X86-64
/usr/local/gcc/bin/gcc -Q --help=target
The following options are target specific:
...
  -march=                               x86-64
...
  -mcpu=                                             
...             
  -mtune=                               generic

Sorry to be so pedantic.