[llvm] [HLSL] Implement DXILResourceBindingAnalysis (PR #137258)

[Ashley Coleman via llvm-commits]

================
@@ -879,8 +883,121 @@ SmallVector<dxil::ResourceInfo *> DXILResourceMap::findByUse(const Value *Key) {
 
 //===----------------------------------------------------------------------===//
 
+void DXILResourceBindingInfo::populate(Module &M, DXILResourceTypeMap &DRTM) {
+  struct Binding {
+    ResourceClass ResClass;
+    uint32_t Space;
+    uint32_t LowerBound;
+    uint32_t UpperBound;
+    Binding(ResourceClass RC, uint32_t Sp, uint32_t LB, uint32_t UB)
+        : ResClass(RC), Space(Sp), LowerBound(LB), UpperBound(UB) {}
+  };
+  SmallVector<Binding> Bindings;
+
+  // collect all of the llvm.dx.resource.handlefrombinding calls;
+  // make a note if there is llvm.dx.resource.handlefromimplicitbinding
+  for (Function &F : M.functions()) {
+    if (!F.isDeclaration())
+      continue;
+
+    switch (F.getIntrinsicID()) {
+    default:
+      continue;
+    case Intrinsic::dx_resource_handlefrombinding: {
+      auto *HandleTy = cast<TargetExtType>(F.getReturnType());
+      ResourceTypeInfo &RTI = DRTM[HandleTy];
+
+      for (User *U : F.users())
+        if (CallInst *CI = dyn_cast<CallInst>(U)) {
+          uint32_t Space =
+              cast<ConstantInt>(CI->getArgOperand(0))->getZExtValue();
+          uint32_t LowerBound =
+              cast<ConstantInt>(CI->getArgOperand(1))->getZExtValue();
+          int32_t Size =
+              cast<ConstantInt>(CI->getArgOperand(2))->getZExtValue();
+
+          // negative size means unbounded resource array;
+          // upper bound register overflow should be detected in Sema
+          assert((Size < 0 || (unsigned)LowerBound + Size - 1 <= UINT32_MAX) &&
+                 "upper bound register overflow");
+          uint32_t UpperBound = Size < 0 ? UINT32_MAX : LowerBound + Size - 1;
+          Bindings.emplace_back(RTI.getResourceClass(), Space, LowerBound,
+                                UpperBound);
+        }
+      break;
+    }
+    case Intrinsic::dx_resource_handlefromimplicitbinding: {
+      if (!F.user_empty())
+        ImplicitBinding = true;
----------------
V-FEXrt wrote:

nit:
```suggestion
      ImplicitBinding = !F.user_empty();
```

https://github.com/llvm/llvm-project/pull/137258