[DebugInfo] Check DIEnumerator bit width when comparing for equality

As mentioned in D106585, this causes non-determinism, which can also be
shown by this test case being flaky without this patch.

We were using the APSInt's bit width for hashing, but not for checking
for equality. APInt::isSameValue() does not check bit width.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D115054

(cherry picked from commit 93a20ec)

Author: aeubanks

llvm/lib/IR/LLVMContextImpl.h

@@ -391,8 +391,9 @@ template <> struct MDNodeKeyImpl<DIEnumerator> {
         IsUnsigned(N->isUnsigned()) {}
 
   bool isKeyOf(const DIEnumerator *RHS) const {
-    return APInt::isSameValue(Value, RHS->getValue()) &&
-           IsUnsigned == RHS->isUnsigned() && Name == RHS->getRawName();
+    return Value.getBitWidth() == RHS->getValue().getBitWidth() &&
+           Value == RHS->getValue() && IsUnsigned == RHS->isUnsigned() &&
+           Name == RHS->getRawName();
   }
 
   unsigned getHashValue() const { return hash_combine(Value, Name); }

llvm/unittests/IR/DebugInfoTest.cpp

@@ -7,8 +7,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/IR/DebugInfo.h"
-#include "llvm/IR/DIBuilder.h"
+#include "llvm/ADT/APSInt.h"
 #include "llvm/AsmParser/Parser.h"
+#include "llvm/IR/DIBuilder.h"
 #include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/LLVMContext.h"
@@ -244,4 +245,21 @@ TEST(DIBuilder, CreateSetType) {
   EXPECT_TRUE(isa_and_nonnull<DIDerivedType>(SetType));
 }
 
+TEST(DIBuilder, DIEnumerator) {
+  LLVMContext Ctx;
+  std::unique_ptr<Module> M(new Module("MyModule", Ctx));
+  DIBuilder DIB(*M);
+  APSInt I1(APInt(32, 1));
+  APSInt I2(APInt(33, 1));
+
+  auto *E = DIEnumerator::get(Ctx, I1, I1.isSigned(), "name");
+  EXPECT_TRUE(E);
+
+  auto *E1 = DIEnumerator::getIfExists(Ctx, I1, I1.isSigned(), "name");
+  EXPECT_TRUE(E1);
+
+  auto *E2 = DIEnumerator::getIfExists(Ctx, I2, I1.isSigned(), "name");
+  EXPECT_FALSE(E2);
+}
+
 } // end namespace