Correctly update bitvector in optAddVnAssertionMapping

When short bitvectors are used only the first assertion was stored in the map stored bitvector, all subsequent assertions were stored into copies of that bitvector.

Commit migrated from https://github.com/dotnet/coreclr/commit/fb604c571325fb1a2d4e2b0d5f98dce61f1f0475

diff --git a/src/coreclr/src/jit/assertionprop.cpp b/src/coreclr/src/jit/assertionprop.cpp
index b804b96..87aa946 100644 (file)
--- a/src/coreclr/src/jit/assertionprop.cpp
+++ b/src/coreclr/src/jit/assertionprop.cpp
@@ -1483,13 +1483,15 @@ void Compiler::optPrintVnAssertionMapping()
  */
 void Compiler::optAddVnAssertionMapping(ValueNum vn, AssertionIndex index)
 {
-    ASSERT_TP cur;
-    if (!optValueNumToAsserts->Lookup(vn, &cur))
+    ASSERT_TP* cur = optValueNumToAsserts->LookupPointer(vn);
+    if (cur == nullptr)
     {
-        cur = BitVecOps::MakeEmpty(apTraits);
-        optValueNumToAsserts->Set(vn, cur);
+        optValueNumToAsserts->Set(vn, BitVecOps::MakeSingleton(apTraits, index - 1));
+    }
+    else
+    {
+        BitVecOps::AddElemD(apTraits, *cur, index - 1);
     }
-    BitVecOps::AddElemD(apTraits, cur, index - 1);
 }
 
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