[clang] [llvm] [HLSL] Implement ddx/ddy_coarse intrinsics (PR #164831)

[Farzon Lotfi via llvm-commits]

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@@ -151,6 +151,18 @@ Value *CodeGenFunction::EmitSPIRVBuiltinExpr(unsigned BuiltinID,
         Intrinsic::spv_global_offset,
         ArrayRef<Value *>{EmitScalarExpr(E->getArg(0))}, nullptr,
         "spv.global.offset");
+  case SPIRV::BI__builtin_spirv_ddx_coarse:
+    return Builder.CreateIntrinsic(
+        /*ReturnType=*/getTypes().ConvertType(E->getType()),
+        Intrinsic::spv_ddx_coarse,
+        ArrayRef<Value *>{EmitScalarExpr(E->getArg(0))}, nullptr,
+        "spv.ddx.coarse");
+  case SPIRV::BI__builtin_spirv_ddy_coarse:
+    return Builder.CreateIntrinsic(
+        /*ReturnType=*/getTypes().ConvertType(E->getType()),
+        Intrinsic::spv_ddy_coarse,
+        ArrayRef<Value *>{EmitScalarExpr(E->getArg(0))}, nullptr,
+        "spv.ddy.coarse");
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farzonl wrote:

This isn't wrong, but is out of scope for how we are doing HLSL intrinsics. we don't just want to add target builtins because we can.  If there is a different project that wants to expand these to make c\c++ a proper frontend for spirv that project can feel free to make this change, but for us this would be equivalent to adding an untested entry point to the spv intrinsics. please revert for this change.

https://github.com/llvm/llvm-project/pull/164831