[clang] [clang][CUDA] Disable float128 diagnostics for device compilation (PR #83918)

[Pranav Kant via cfe-commits]

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@@ -4877,7 +4877,9 @@ void Sema::AddModeAttr(Decl *D, const AttributeCommonInfo &CI,
     NewElemTy = Context.getRealTypeForBitwidth(DestWidth, ExplicitType);
 
   if (NewElemTy.isNull()) {
-    Diag(AttrLoc, diag::err_machine_mode) << 1 /*Unsupported*/ << Name;
+    // Only emit diagnostic on host for 128-bit mode attribute
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pranavk wrote:

There are two diags that I disabled as part of this PR:
1. "%0 is not supported on this target"
2. unsupported machine mode __TC__

The diag that got emitted as part of building sample snippet that you pasted in this comment thread is neither 1 nor 2. This diag comes from part of clang/LLVM when it starts to generate code for nvptx specifically.

https://github.com/llvm/llvm-project/pull/83918