ABataev added inline comments.
================
Comment at: clang/lib/Sema/SemaOpenMP.cpp:1596
<< Ty << E->getSourceRange();
+ if (Ty->isRealFloatingType()) {
+ llvm::APFloatBase::Semantics Sem = llvm::APFloatBase::SemanticsToEnum(
----------------
jdenny wrote:
> ABataev wrote:
> > jdenny wrote:
> > > ABataev wrote:
> > > > jdenny wrote:
> > > > > ABataev wrote:
> > > > > > jdenny wrote:
> > > > > > > ABataev wrote:
> > > > > > > > Why do we need all this stuff? I think the original code works
> > > > > > > > good here, we just need to improve the message.
> > > > > > > > Why do we need all this stuff? I think the original code works
> > > > > > > > good here, we just need to improve the message.
> > > > > > >
> > > > > > > It seems we've been miscommunicating. Let's review the
> > > > > > > discussion so far, point by point, and I'll show you how I
> > > > > > > arrived at this code. I think the first major point is as
> > > > > > > follows.
> > > > > > >
> > > > > > > I asked:
> > > > > > > > Are you intentionally requiring support for __float128 when the
> > > > > > > > source type is 128-bit long double? That seems to mean
> > > > > > > > powerpc64le cannot offload to itself.
> > > > > > >
> > > > > > > You replied:
> > > > > > > > No, if the host has 128 bit long double, the device must also
> > > > > > > > have 128 bit long double. It has nothing to do with the
> > > > > > > > float128 type itself.
> > > > > > >
> > > > > > > I thought you were agreeing with my understanding. That is, the
> > > > > > > original code requires `__float128` support even when 128-bit
> > > > > > > `long double` is in use. That's why powerpc64le cannot offload
> > > > > > > to itself. How does the original code require `__float128`? It
> > > > > > > checks `Context.getTargetInfo().hasFloat128Type()`. As far as I
> > > > > > > can tell, that checks for `__float128` support, and it does not
> > > > > > > check for 128-bit `long double` support. That's why powerpc64le
> > > > > > > cannot offload to itself.
> > > > > > >
> > > > > > > I'll review other points later so we can discuss them. First,
> > > > > > > let's see if we can agree on this point.
> > > > > > >
> > > > > > My point about ppc64le is:
> > > > > > If the host code uses long double 128 bit long, tbe device long
> > > > > > double also must be 128 bit long. But if device does not support
> > > > > > 128bit FP type naturally, user cannot do any operations with it
> > > > > > except just load/stores.
> > > > > > Forget about float128 type, we talk about 128bit long double here.
> > > > > This patch adds new testing for powerpc64le. Without the rest of
> > > > > this patch (and without the `expected-error` change), should that
> > > > > pass? It does not for me.
> > > > Just like I said before, it means that your device config does not
> > > > match the expected one. It means that either you specified incorrect
> > > > triple, or the device is not configured properly.
> > > The triple is in the new test code. Is it incorrect?
> > >
> > > When you discussed device configuration earlier, you made a comment about
> > > 64 bit FP, and I couldn't find evidence of that anywhere.
> > >
> > > When I explore the device config as you suggested earlier, as far as I
> > > can tell, the only issue here is that it claims powerpc64le does not
> > > support `__float128`, but the original logic in
> > > `Sema::checkOpenMPDeviceExpr` requires `__float128` by checking
> > > `Context.getTargetInfo().hasFloat128Type()`.
> > Original ppc64le host reports that it supports 128bit float. The device
> > reports that it does not support it. It just means that the device has
> > different configuration than host. If yoh want the device to support 128
> > bit FP as the host, you need either to specify the device correctly, orfix
> > the target device configuration in the lib/Basic/Target if it does not
> > match the expected behavior.
> > Check the host init for ppc64le. It sets hasFloat128 to true. For some
> > reason, device target config does not set this flag and reports that it
> > does not support 128bit FP.
> > Original ppc64le host reports that it supports 128bit float.
>
> > Check the host init for ppc64le. It sets hasFloat128 to true.
>
> Doesn't appear to happen for me unless I add `-target-feature +float128` as a
> `-cc1` option, as some existing powerpc64le clang tests do.
>
> @MaskRay, will powerpc64le set `HasFloat128=true` after your changes?
>
This is what I meant! We just missed some special target config options for the
device.
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D64289/new/
https://reviews.llvm.org/D64289
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