[HLSL] Remove unused frontend-generated ID

[beanz]

Summary

As @python3kgae pointed out we're going to want to assign these IDs
after optimization so that we can remove unused resrouces. This patch
just removes the unused ID value from the frontend metadata, clang code
generation, and updates associated test cases.

clang/lib/CodeGen/CGHLSLRuntime.h

struct Buffer {
     BufferResBinding Binding;
     // Global variable and offset for each constant.
     std::vector<std::pair<llvm::GlobalVariable *, unsigned>> Constants;
     llvm::StructType *LayoutStruct = nullptr;
   };
 
 protected:
   CodeGenModule &CGM;
-  uint32_t ResourceCounters[static_cast<uint32_t>(
-      llvm::hlsl::ResourceClass::NumClasses)] = {0};
 
   llvm::Value *emitInputSemantic(llvm::IRBuilder<> &B, const ParmVarDecl &D,
                                  llvm::Type *Ty);
 
 public:
   CGHLSLRuntime(CodeGenModule &CGM) : CGM(CGM) {}
   virtual ~CGHLSLRuntime() {}
 

clang/lib/CodeGen/CGHLSLRuntime.cpp

CGHLSLRuntime::Buffer::Buffer(const HLSLBufferDecl *D)
     : Name(D->getName()), IsCBuffer(D->isCBuffer()),
       Binding(D->getAttr<HLSLResourceBindingAttr>()) {}
 
 void CGHLSLRuntime::addBufferResourceAnnotation(llvm::GlobalVariable *GV,
                                                 llvm::StringRef TyName,
                                                 llvm::hlsl::ResourceClass RC,
                                                 llvm::hlsl::ResourceKind RK,
                                                 BufferResBinding &Binding) {
-  uint32_t Counter = ResourceCounters[static_cast<uint32_t>(RC)]++;
   llvm::Module &M = CGM.getModule();
 
   NamedMDNode *ResourceMD = nullptr;
   switch (RC) {
   case llvm::hlsl::ResourceClass::UAV:
     ResourceMD = M.getOrInsertNamedMetadata("hlsl.uavs");
     break;
   case llvm::hlsl::ResourceClass::SRV:
     ResourceMD = M.getOrInsertNamedMetadata("hlsl.srvs");
     break;
   case llvm::hlsl::ResourceClass::CBuffer:
     ResourceMD = M.getOrInsertNamedMetadata("hlsl.cbufs");
     break;
   default:
     assert(false && "Unsupported buffer type!");
     return;
   }
 
   assert(ResourceMD != nullptr &&
          "ResourceMD must have been set by the switch above.");
 
   llvm::hlsl::FrontendResource Res(
-      GV, TyName, Counter, RK, Binding.Reg.value_or(UINT_MAX), Binding.Space);
+      GV, TyName, RK, Binding.Reg.value_or(UINT_MAX), Binding.Space);
   ResourceMD->addOperand(Res.getMetadata());
 }
 
 static llvm::hlsl::ResourceKind
 castResourceShapeToResourceKind(HLSLResourceAttr::ResourceKind RK) {
   switch (RK) {
   case HLSLResourceAttr::ResourceKind::Texture1D:
     return llvm::hlsl::ResourceKind::Texture1D;

clang/test/CodeGenHLSL/builtins/RWBuffer-annotations.hlsl

 
 
 
 [numthreads(1,1,1)]
 void main() {
 }
 
 // CHECK: !hlsl.uavs = !{![[Single:[0-9]+]], ![[Array:[0-9]+]], ![[SingleAllocated:[0-9]+]], ![[ArrayAllocated:[0-9]+]], ![[SingleSpace:[0-9]+]], ![[ArraySpace:[0-9]+]]}
-// CHECK-DAG: ![[Single]] = !{ptr @"?Buffer1@@3V?$RWBuffer@M@hlsl@@A", !"RWBuffer<float>", i32 0, i32 10, i32 -1, i32 0}
-// CHECK-DAG: ![[Array]] = !{ptr @"?BufferArray@@3PAV?$RWBuffer@T?$__vector@M$03@__clang@@@hlsl@@A", !"RWBuffer<vector<float, 4> >", i32 1, i32 10, i32 -1, i32 0}
-// CHECK-DAG: ![[SingleAllocated]] = !{ptr @"?Buffer2@@3V?$RWBuffer@M@hlsl@@A", !"RWBuffer<float>", i32 2, i32 10, i32 3, i32 0}
-// CHECK-DAG: ![[ArrayAllocated]] = !{ptr @"?BufferArray2@@3PAV?$RWBuffer@T?$__vector@M$03@__clang@@@hlsl@@A", !"RWBuffer<vector<float, 4> >", i32 3, i32 10, i32 4, i32 0}
-// CHECK-DAG: ![[SingleSpace]] = !{ptr @"?Buffer3@@3V?$RWBuffer@M@hlsl@@A", !"RWBuffer<float>", i32 4, i32 10, i32 3, i32 1}
-// CHECK-DAG: ![[ArraySpace]] = !{ptr @"?BufferArray3@@3PAV?$RWBuffer@T?$__vector@M$03@__clang@@@hlsl@@A", !"RWBuffer<vector<float, 4> >", i32 5, i32 10, i32 4, i32 1}
+// CHECK-DAG: ![[Single]] = !{ptr @"?Buffer1@@3V?$RWBuffer@M@hlsl@@A", !"RWBuffer<float>", i32 10, i32 -1, i32 0}
+// CHECK-DAG: ![[Array]] = !{ptr @"?BufferArray@@3PAV?$RWBuffer@T?$__vector@M$03@__clang@@@hlsl@@A", !"RWBuffer<vector<float, 4> >", i32 10, i32 -1, i32 0}
+// CHECK-DAG: ![[SingleAllocated]] = !{ptr @"?Buffer2@@3V?$RWBuffer@M@hlsl@@A", !"RWBuffer<float>", i32 10, i32 3, i32 0}
+// CHECK-DAG: ![[ArrayAllocated]] = !{ptr @"?BufferArray2@@3PAV?$RWBuffer@T?$__vector@M$03@__clang@@@hlsl@@A", !"RWBuffer<vector<float, 4> >", i32 10, i32 4, i32 0}
+// CHECK-DAG: ![[SingleSpace]] = !{ptr @"?Buffer3@@3V?$RWBuffer@M@hlsl@@A", !"RWBuffer<float>", i32 10, i32 3, i32 1}
+// CHECK-DAG: ![[ArraySpace]] = !{ptr @"?BufferArray3@@3PAV?$RWBuffer@T?$__vector@M$03@__clang@@@hlsl@@A", !"RWBuffer<vector<float, 4> >", i32 10, i32 4, i32 1}

clang/test/CodeGenHLSL/cbuf.hlsl

 // CHECK: load double, ptr getelementptr inbounds ({ float, double }, ptr @[[CB]], i32 0, i32 1), align 8
 // CHECK: load float, ptr @[[TB]], align 4
 // CHECK: load double, ptr getelementptr inbounds ({ float, double }, ptr @[[TB]], i32 0, i32 1), align 8
   return a + b + c*d;
 }
 
 // CHECK: !hlsl.cbufs = !{![[CBMD:[0-9]+]]}
 // CHECK: !hlsl.srvs = !{![[TBMD:[0-9]+]]}
-// CHECK: ![[CBMD]] = !{ptr @[[CB]], !"A.cb.ty", i32 0, i32 13, i32 0, i32 2}
-// CHECK: ![[TBMD]] = !{ptr @[[TB]], !"A.tb.ty", i32 0, i32 15, i32 2, i32 1}
+// CHECK: ![[CBMD]] = !{ptr @[[CB]], !"A.cb.ty", i32 13, i32 0, i32 2}
+// CHECK: ![[TBMD]] = !{ptr @[[TB]], !"A.tb.ty", i32 15, i32 2, i32 1}

llvm/include/llvm/Frontend/HLSL/HLSLResource.h

enum class ResourceKind : uint32_t {
   NumEntries,
 };
 
 class FrontendResource {
   MDNode *Entry;
 
 public:
   FrontendResource(MDNode *E) : Entry(E) {
-    assert(Entry->getNumOperands() == 6 && "Unexpected metadata shape");
+    assert(Entry->getNumOperands() == 5 && "Unexpected metadata shape");
   }
 
-  FrontendResource(GlobalVariable *GV, StringRef TypeStr, uint32_t Counter,
-                   ResourceKind RK, uint32_t ResIndex, uint32_t Space);
+  FrontendResource(GlobalVariable *GV, StringRef TypeStr, ResourceKind RK,
+                   uint32_t ResIndex, uint32_t Space);
 
   GlobalVariable *getGlobalVariable();
   StringRef getSourceType();
-  Constant *getID();
   uint32_t getResourceKind();
   uint32_t getResourceIndex();
   uint32_t getSpace();
   MDNode *getMetadata() { return Entry; }
 };
 } // namespace hlsl
 } // namespace llvm
 
 #endif // LLVM_FRONTEND_HLSL_HLSLRESOURCE_H

llvm/lib/Frontend/HLSL/HLSLResource.cpp

GlobalVariable *FrontendResource::getGlobalVariable() {
   return cast<GlobalVariable>(
       cast<ConstantAsMetadata>(Entry->getOperand(0))->getValue());
 }
 
 StringRef FrontendResource::getSourceType() {
   return cast<MDString>(Entry->getOperand(1))->getString();
 }
 
-Constant *FrontendResource::getID() {
-  return cast<ConstantAsMetadata>(Entry->getOperand(2))->getValue();
-}
-
 uint32_t FrontendResource::FrontendResource::getResourceKind() {
   return cast<ConstantInt>(
-             cast<ConstantAsMetadata>(Entry->getOperand(3))->getValue())
+             cast<ConstantAsMetadata>(Entry->getOperand(2))->getValue())
       ->getLimitedValue();
 }
 uint32_t FrontendResource::getResourceIndex() {
   return cast<ConstantInt>(
-             cast<ConstantAsMetadata>(Entry->getOperand(4))->getValue())
+             cast<ConstantAsMetadata>(Entry->getOperand(3))->getValue())
       ->getLimitedValue();
 }
 uint32_t FrontendResource::getSpace() {
   return cast<ConstantInt>(
-             cast<ConstantAsMetadata>(Entry->getOperand(5))->getValue())
+             cast<ConstantAsMetadata>(Entry->getOperand(4))->getValue())
       ->getLimitedValue();
 }
 
 FrontendResource::FrontendResource(GlobalVariable *GV, StringRef TypeStr,
-                                   uint32_t Counter, ResourceKind RK,
-                                   uint32_t ResIndex, uint32_t Space) {
+                                   ResourceKind RK, uint32_t ResIndex,
+                                   uint32_t Space) {
   auto &Ctx = GV->getContext();
   IRBuilder<> B(Ctx);
   Entry = MDNode::get(
       Ctx, {ValueAsMetadata::get(GV), MDString::get(Ctx, TypeStr),
-            ConstantAsMetadata::get(B.getInt32(Counter)),
             ConstantAsMetadata::get(B.getInt32(static_cast<int>(RK))),
             ConstantAsMetadata::get(B.getInt32(ResIndex)),
             ConstantAsMetadata::get(B.getInt32(Space))});
 }

llvm/test/CodeGen/DirectX/UAVMetadata.ll

 @Six = local_unnamed_addr global %"class.hlsl::RWBuffer" zeroinitializer, align 4
 @Seven = local_unnamed_addr global %"class.hlsl::RWBuffer" zeroinitializer, align 4
 @Eight = local_unnamed_addr global %"class.hlsl::RWBuffer" zeroinitializer, align 4
 @Nine = local_unnamed_addr global %"class.hlsl::RWBuffer" zeroinitializer, align 4
 
 
 !hlsl.uavs = !{!0, !1, !2, !3, !4, !5, !6, !7, !8, !9}
 
-!0 = !{ptr @Zero, !"RWBuffer<half>", i32 0, i32 10, i32 0, i32 0}
-!1 = !{ptr @One, !"Buffer<vector<float,4>>", i32 1, i32 10, i32 1, i32 0}
-!2 = !{ptr @Two, !"Buffer<double>", i32 2, i32 10, i32 2, i32 0}
-!3 = !{ptr @Three, !"Buffer<bool>", i32 3, i32 10, i32 3, i32 0}
-!4 = !{ptr @Four, !"ByteAddressBuffer<int16_t>", i32 4, i32 11, i32 5, i32 0}
-!5 = !{ptr @Five, !"StructuredBuffer<uint16_t>", i32 5, i32 12, i32 6, i32 0}
-!6 = !{ptr @Six, !"RasterizerOrderedBuffer<int32_t>", i32 6, i32 10, i32 7, i32 0}
-!7 = !{ptr @Seven, !"RasterizerOrderedStructuredBuffer<uint32_t>", i32 7, i32 12, i32 8, i32 0}
-!8 = !{ptr @Eight, !"RasterizerOrderedByteAddressBuffer<int64_t>", i32 8, i32 11, i32 9, i32 0}
-!9 = !{ptr @Nine, !"RWBuffer<uint64_t>", i32 9, i32 10, i32 10, i32 2}
+!0 = !{ptr @Zero, !"RWBuffer<half>", i32 10, i32 0, i32 0}
+!1 = !{ptr @One, !"Buffer<vector<float,4>>", i32 10, i32 1, i32 0}
+!2 = !{ptr @Two, !"Buffer<double>", i32 10, i32 2, i32 0}
+!3 = !{ptr @Three, !"Buffer<bool>", i32 10, i32 3, i32 0}
+!4 = !{ptr @Four, !"ByteAddressBuffer<int16_t>", i32 11, i32 5, i32 0}
+!5 = !{ptr @Five, !"StructuredBuffer<uint16_t>", i32 12, i32 6, i32 0}
+!6 = !{ptr @Six, !"RasterizerOrderedBuffer<int32_t>", i32 10, i32 7, i32 0}
+!7 = !{ptr @Seven, !"RasterizerOrderedStructuredBuffer<uint32_t>", i32 12, i32 8, i32 0}
+!8 = !{ptr @Eight, !"RasterizerOrderedByteAddressBuffer<int64_t>", i32 11, i32 9, i32 0}
+!9 = !{ptr @Nine, !"RWBuffer<uint64_t>", i32 10, i32 10, i32 2}
 
 ; CHECK: !dx.resources = !{[[ResList:[!][0-9]+]]}
 
 ; CHECK: [[ResList]] = !{null, [[UAVList:[!][0-9]+]], null, null}
 ; CHECK: [[UAVList]] = !{[[Zero:[!][0-9]+]], [[One:[!][0-9]+]],
 ; CHECK-SAME: [[Two:[!][0-9]+]], [[Three:[!][0-9]+]], [[Four:[!][0-9]+]], 
 ; CHECK-SAME: [[Five:[!][0-9]+]], [[Six:[!][0-9]+]], [[Seven:[!][0-9]+]],
 ; CHECK-SAME: [[Eight:[!][0-9]+]], [[Nine:[!][0-9]+]]}