[Bug target/88535] sparcv9 gcc 7 causes comparison failure in sparc gcc 8 dwarf2out.o

[ro at CeBiTec dot Uni-Bielefeld.DE]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88535

--- Comment #14 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> ---
> --- Comment #11 from john henning <mailboxnotfound at yahoo dot com> ---
>> There are 3 different switches: --build, --host and --target.
>
> Hmm.  I must be looking in the wrong place for documentation; are these
> explained somewhere?  
>
> At https://gcc.gnu.org/install/configure.html I see a description of 
>    --target
> and a brief mention of 
>    --host
> but no definition.  There doesn't seem to be a description for --build.

That's because all three are common configure switches, thus described
in the autoconf manual.

If none is given, config.guess tries it's best to determine them.
Otherwise, the --host value defaults to the --build one if not given
explicitly, and likewise --target to --host.

I've seen cases (don't remember the details) when this didn't work as
expected, so I tend to pass all three to avoid trouble (like configure
configure wrongly assuming it's a cross build when in fact it's a native
one).