[PATCH] D54486: BumpPtrAllocator: Add a couple of fancy wrapper methods around identifyObject().

[Artem Dergachev via Phabricator via llvm-commits]

NoQ created this revision.
NoQ added reviewers: george.karpenkov, chandlerc.
Herald added subscribers: llvm-commits, kristina.

So far all 5 uses of the API introduced in https://reviews.llvm.org/D51393 looked exactly like the proposed `idenfityKnownAlignedObject()`.


Repository:
  rL LLVM

https://reviews.llvm.org/D54486

Files:
  include/llvm/Support/Allocator.h


Index: include/llvm/Support/Allocator.h
===================================================================
--- include/llvm/Support/Allocator.h
+++ include/llvm/Support/Allocator.h
@@ -311,6 +311,27 @@
     return None;
   }
 
+  /// A convenient wrapper around identifyObject that additionally
+  /// asserts that the object is indeed within the allocator.
+  int64_t identifyKnownObject(const void *Ptr) {
+    Optional<int64_t> Out = identifyObject(Ptr);
+    assert(Out && "Wrong allocator used");
+    return *Out;
+  }
+
+  /// A convenient wrapper around identifyKnownObject. Accepts type information
+  /// about the object and produces a smaller identifier by relying on
+  /// the alignment information. Note that sub-classes may have different
+  /// alignment, so the most base class should be passed as template parameter
+  /// in order to obtain correct results. For that reason automatic template
+  /// parameter deduction is disabled.
+  template <typename T>
+  int64_t identifyKnownAlignedObject(const void *Ptr) {
+    int64_t Out = identifyKnownObject(Ptr);
+    assert(Out % alignof(T) == 0 && "Wrong alignment information");
+    return Out / alignof(T);
+  }
+
   size_t getTotalMemory() const {
     size_t TotalMemory = 0;
     for (auto I = Slabs.begin(), E = Slabs.end(); I != E; ++I)


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