[llvm] [HLSL][DirectX] Extract HLSLBinding out of DXILResource. NFC (PR #150633)

[Helena Kotas via llvm-commits]

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@@ -0,0 +1,141 @@
+//===- HLSLBinding.cpp - Representation for resource bindings in HLSL -----===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Frontend/HLSL/HLSLBinding.h"
+#include "llvm/ADT/STLExtras.h"
+
+using namespace llvm;
+using namespace hlsl;
+
+std::optional<uint32_t>
+BindingInfo::findAvailableBinding(dxil::ResourceClass RC, uint32_t Space,
+                                  int32_t Size) {
+  BindingSpaces &BS = getBindingSpaces(RC);
+  RegisterSpace &RS = BS.getOrInsertSpace(Space);
+  return RS.findAvailableBinding(Size);
+}
+
+BindingInfo::RegisterSpace &
+BindingInfo::BindingSpaces::getOrInsertSpace(uint32_t Space) {
+  for (auto *I = Spaces.begin(); I != Spaces.end(); ++I) {
+    if (I->Space == Space)
+      return *I;
+    if (I->Space < Space)
+      continue;
+    return *Spaces.insert(I, Space);
+  }
+  return Spaces.emplace_back(Space);
+}
+
+std::optional<uint32_t>
+BindingInfo::RegisterSpace::findAvailableBinding(int32_t Size) {
+  assert((Size == -1 || Size > 0) && "invalid size");
+
+  if (FreeRanges.empty())
+    return std::nullopt;
+
+  // unbounded array
+  if (Size == -1) {
+    BindingRange &Last = FreeRanges.back();
+    if (Last.UpperBound != UINT32_MAX)
+      // this space is already occupied by an unbounded array
+      return std::nullopt;
+    uint32_t RegSlot = Last.LowerBound;
+    FreeRanges.pop_back();
+    return RegSlot;
+  }
+
+  // single resource or fixed-size array
+  for (BindingRange &R : FreeRanges) {
+    // compare the size as uint64_t to prevent overflow for range (0,
+    // UINT32_MAX)
+    if ((uint64_t)R.UpperBound - R.LowerBound + 1 < (uint64_t)Size)
+      continue;
+    uint32_t RegSlot = R.LowerBound;
+    // This might create a range where (LowerBound == UpperBound + 1). When
+    // that happens, the next time this function is called the range will
+    // skipped over by the check above (at this point Size is always > 0).
+    R.LowerBound += Size;
+    return RegSlot;
+  }
+
+  return std::nullopt;
+}
+
+BindingInfo BindingInfoBuilder::calculateBindingInfo(
+    llvm::function_ref<void(const BindingInfoBuilder &Builder,
+                            const Binding &Overlapping)>
+        ReportOverlap) {
+  // sort all the collected bindings
+  llvm::stable_sort(Bindings);
+
+  // remove duplicates
----------------
hekota wrote:

The resource binding analysis in `DXILResourceBindingInfo::populate` calls tze builder's `trackBinding` for each `handlefrombinding` call it finds in the code and there can by multiple such calls for the same resource.

https://github.com/llvm/llvm-project/pull/150633