Renaming vec_step in tree-vect-loop.c (to fix build on powerpc/clang)

[Richard Sandiford]

Gerald Pfeifer <gerald@pfeifer.com> writes:
> I have seen an increasing number of reports of GCC failing to
> build with clang on powerpc (on FreeBSD, though that's probably
> immaterial).
>
> Turns out that clang has vec_step as a reserved word on powerpc
> with AltiVec.
>
> We OTOH use vec_step s as a variable name in gcc/tree-vect-loop.c.
>
>
> The best approach I can see is to rename vec_step.  Before I prepare
> a patch: what alternate name/spelling would you prefer?

Would it work to #define vec_step to vec_step_ or something on affected
hosts, say in system.h?

I'd prefer that to renmaing since "vec_step" does seem the most natural
name for the variable.  The equivalent scalar variable is "step" and
other vector values in the surrounding code also use the "vec_" prefix.

Thanks,
Richard