[llvm-branch-commits] [clang] [HLSL] Implement Texture2D::Load methods and builtin (PR #185708)

[Helena Kotas via llvm-branch-commits]

================
@@ -3459,6 +3459,56 @@ static bool CheckGatherBuiltin(Sema &S, CallExpr *TheCall, bool IsCmp) {
 
   return false;
 }
+static bool CheckLoadLevelBuiltin(Sema &S, CallExpr *TheCall) {
+  if (S.checkArgCountRange(TheCall, 2, 3))
+    return true;
+
+  // Check the texture handle.
+  if (CheckResourceHandle(&S, TheCall, 0,
+                          [](const HLSLAttributedResourceType *ResType) {
+                            return ResType->getAttrs().ResourceDimension ==
+                                   llvm::dxil::ResourceDimension::Unknown;
+                          }))
+    return true;
+
+  auto *ResourceTy =
+      TheCall->getArg(0)->getType()->castAs<HLSLAttributedResourceType>();
+
+  // Check the location + lod (int3 for Texture2D).
+  unsigned ExpectedDim =
+      getResourceDimensions(ResourceTy->getAttrs().ResourceDimension);
+  QualType CoordLODTy = TheCall->getArg(1)->getType();
+  if (CheckVectorElementCount(&S, CoordLODTy, S.Context.IntTy, ExpectedDim + 1,
+                              TheCall->getArg(1)->getBeginLoc()))
+    return true;
+
+  QualType EltTy = CoordLODTy;
+  if (const auto *VTy = EltTy->getAs<VectorType>())
+    EltTy = VTy->getElementType();
+  if (!EltTy->isIntegerType()) {
+    S.Diag(TheCall->getArg(1)->getBeginLoc(), diag::err_typecheck_expect_int)
+        << CoordLODTy;
+    return true;
+  }
+
+  // Check the offset operand.
+  if (TheCall->getNumArgs() > 2) {
+    if (CheckVectorElementCount(&S, TheCall->getArg(2)->getType(),
+                                S.Context.IntTy, ExpectedDim,
+                                TheCall->getArg(2)->getBeginLoc()))
+      return true;
+  }
+
+  QualType ReturnType = ResourceTy->getContainedType();
+  if (const auto *VecTy = ReturnType->getAs<VectorType>())
+    ReturnType = VecTy->getElementType();
+  ReturnType = S.Context.getExtVectorType(ReturnType, 4);
+
+  TheCall->setType(ReturnType);
----------------
hekota wrote:

```suggestion
  TheCall->setType(ResourceTy->getContainedType(););
```
I believe the return type should be the texture's template type.

https://github.com/llvm/llvm-project/pull/185708