On 12/5/19 2:44 AM, Iain Sandoe wrote:
> Segher Boessenkool <seg...@kernel.crashing.org> wrote:
>> On Wed, Dec 04, 2019 at 03:53:30PM -0600, Peter Bergner wrote:
>>> Sure, I can add a test in gcc.target/powerpc/ that uses both a builtin
>>> and an overloaded builtin to make sure we don't ICE when DFP is disabled.
>>
>> Great, thanks!
>
> so that would be a/some dg-do compile test(s), then?
> (presumably, gated on effective_target_dfp … see below)
Yes, only a dg-do compile test. For DFP enabled targets, they shouldn't
see any errors at all and for DFP disabled targets, I'd insert some
dg-error checks gated on ![check_effective_target_dfp] looking for the
"error: decimal floating-point not supported for this target" errors.
Any ICE would flag a real test case error.
> (on r278957, with the system assembler which doesn’t support DFP insns
> and gcc.target dfp.exp not yet renamed)
>
> # Skip these tests for targets that don't support this extension.
> if { ![check_effective_target_dfp] } {
> return;
> }
>
> Works on Darwin to skip the entire set (not too much of a surprise, since
> it’s used for the GCC and G++ cases already).
Great, thanks for checking.
> It’s possible (even likely) that Darwin can be built with an assembler that
> supports DFP instructions, even tho it has no OS support. Usually, my policy
> is that we would do compile tests then, since that excercises more code.
My --disable-decimal-float run also worked and I had an assembler that
supports all of the DFP insns, so I'd expect it to work for you too.
The check_effective_target_dfp tests really is checking for whether the
DFP modes exist in the compiler and that isn't gated on the assembler...
at least fully.
> ..but then we need to gate run tests on the availability of runtime support.
There exists check_effective_target_dfprt for that.
> I see that the GCC and G++ testsuites have also….
>
> # If the decimal float is supported in the compiler but not yet in the
> # runtime, treat all tests as compile-only.
> global dg-do-what-default
> set save-dg-do-what-default ${dg-do-what-default}
> if { ![check_effective_target_dfprt] } {
> verbose "dfp.exp: runtime support for decimal float does not exist" 2
> set dg-do-what-default compile
> } else {
> verbose "dfp.exp: runtime support for decimal float exists, use it" 2
> set dg-do-what-default run
> }
> verbose "dfp.exp: dg-do-what-default is ${dg-do-what-default}” 2
>
> Do you think there’s any merit in doing something like that here too?
Adding this to powerpc/dfp/dfp.exp won't do anything, since all of the
powerpc/dfp/ tests are dg-do compile tests.
> (I guess a finer-grained alternative is check_effective_target_dfprt in any
> run-tests)
>
> .. or I can just force a false return from effective_target_dfp as we
> do for other cases where assembler support does not imply system
> support.
I've already verified that if decimal float is disabled, but you do
have an assembler that supports dfp insns, check_effective_target_dfp
still works correctly.
Peter
