[clang] [llvm] [HLSL] Implicit resource binding for cbuffers (PR #139022)

[Shafik Yaghmour via llvm-commits]

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@@ -539,19 +537,29 @@ static void initializeBuffer(CodeGenModule &CGM, llvm::GlobalVariable *GV,
 }
 
 static void initializeBufferFromBinding(CodeGenModule &CGM,
-                                        llvm::GlobalVariable *GV, unsigned Slot,
-                                        unsigned Space) {
+                                        llvm::GlobalVariable *GV,
+                                        HLSLResourceBindingAttr *RBA) {
   llvm::Type *Int1Ty = llvm::Type::getInt1Ty(CGM.getLLVMContext());
-  llvm::Value *Args[] = {
-      llvm::ConstantInt::get(CGM.IntTy, Space), /* reg_space */
-      llvm::ConstantInt::get(CGM.IntTy, Slot),  /* lower_bound */
-      llvm::ConstantInt::get(CGM.IntTy, 1),     /* range_size */
-      llvm::ConstantInt::get(CGM.IntTy, 0),     /* index */
-      llvm::ConstantInt::get(Int1Ty, false)     /* non-uniform */
-  };
-  initializeBuffer(CGM, GV,
-                   CGM.getHLSLRuntime().getCreateHandleFromBindingIntrinsic(),
-                   Args);
+  auto *NonUniform = llvm::ConstantInt::get(Int1Ty, false);
+  auto *Index = llvm::ConstantInt::get(CGM.IntTy, 0);
+  auto *RangeSize = llvm::ConstantInt::get(CGM.IntTy, 1);
+  auto *Space =
+      llvm::ConstantInt::get(CGM.IntTy, RBA ? RBA->getSpaceNumber() : 0);
+
+  if (RBA->hasRegisterSlot()) {
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shafik wrote:

You are unconditionally dereferencing `RBA` here just the line before you are using conditional operator to check if `RBA` is `nullptr`. One of these lines is in error.

https://github.com/llvm/llvm-project/pull/139022