[PATCH] D115054: [DebugInfo] Check DIEnumerator bit width when comparing for equality

[Arthur Eubanks via Phabricator via llvm-commits]

aeubanks created this revision.
aeubanks added reviewers: rnk, dblaikie, glandium.
Herald added subscribers: dexonsmith, hiraditya.
aeubanks requested review of this revision.
Herald added a project: LLVM.
Herald added a subscriber: llvm-commits.

As mentioned in D106585 <https://reviews.llvm.org/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.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D115054

Files:
  llvm/lib/IR/LLVMContextImpl.h
  llvm/unittests/IR/DebugInfoTest.cpp


Index: llvm/unittests/IR/DebugInfoTest.cpp
===================================================================
--- llvm/unittests/IR/DebugInfoTest.cpp
+++ 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 @@
   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
Index: llvm/lib/IR/LLVMContextImpl.h
===================================================================
--- llvm/lib/IR/LLVMContextImpl.h
+++ llvm/lib/IR/LLVMContextImpl.h
@@ -386,8 +386,9 @@
         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); }


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