Re: [PATCH, rs6000, committed] Fix gcc.target/powerpc/p8-vec-xl-xst.c target selector

[Segher Boessenkool <segher@kernel.crashing.org>]

On Mon, May 22, 2017 at 08:14:13PM +0000, Joseph Myers wrote:
> > The subject test requires little endian, but the target selector doesn't
> > specify this.  This patch fixes that.  Tested on BE/LE P8 systems,
> > committed as obvious.
> 
> It's not obvious; it's wrong.  You can configure for a BE default while 
> supporting LE, using appropriate --enable-targets options.  That's what 
> config/rs6000/t-linux64bele is for, for example.  In such cases, this test 
> should be enabled when testing LE multilibs.  Likewise, you can configure 
> for LE default while supporting BE, and then the test should be disabled 
> when testing BE multilibs.
> 
> For any target property that can depend on the multilib, you have to use a 
> general target pattern such as powerpc*-*-*, then test effective-target 
> keywords for any per-multilib properties that are relevant (such as 
> endianness in this case).  Testing for BE/LE, or for 32-bit/64-bit, via 
> target triplet patterns, is always wrong in powerpc tests, just as it's 
> always wrong for x86 tests to support one of x86_64 and i?86 but not the 
> other (those should similarly use effective-targets as needed).

Yes, all this is true.  But the patch is an obvious improvement, and in
line with the many other tests where we have this test for powerpc64le-*-*.

As far as I know no one tests LE on a BE system, and the other way around.
But yes you are right, it should be supported, just like powerpc64 on a
non-powerpc64 system (and importantly, the other way around), for which
we currently use lp64 (which isn't exactly right), except of course the
tests that do it completely wrong :-/


Segher