jdenny added inline comments.

================
Comment at: clang/lib/Sema/SemaOpenMP.cpp:1596
         << Ty << E->getSourceRange();
+  if (Ty->isRealFloatingType()) {
+    llvm::APFloatBase::Semantics Sem = llvm::APFloatBase::SemanticsToEnum(
----------------
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?



CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D64289/new/

https://reviews.llvm.org/D64289



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