[clang] [llvm] [NVPTX] Cleanup and document nvvm.fabs intrinsics, adding f16 support (PR #135644)

[Alex MacLean via cfe-commits]

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@@ -1034,6 +1034,10 @@ Value *CodeGenFunction::EmitNVPTXBuiltinExpr(unsigned BuiltinID,
   case NVPTX::BI__nvvm_fmin_xorsign_abs_f16x2:
     return MakeHalfType(Intrinsic::nvvm_fmin_xorsign_abs_f16x2, BuiltinID, E,
                         *this);
+  case NVPTX::BI__nvvm_abs_bf16:
+  case NVPTX::BI__nvvm_abs_bf16x2:
+    return Builder.CreateUnaryIntrinsic(Intrinsic::nvvm_fabs,
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AlexMaclean wrote:

@Artem-B In the most recent iteration I update the clang frontend, which is certainly not my area of expertise. Please let me know if this looks okay, or if there are any changes required.

https://github.com/llvm/llvm-project/pull/135644