Address comments from ellishg

Author: kyulee-com

llvm/include/llvm/ADT/StableHashing.h

@@ -61,7 +61,8 @@ inline StringRef get_stable_name(StringRef Name) {
 // Generates a consistent hash value for a given input name across different
 // program executions and environments. This function first converts the input
 // name into a stable form using the `get_stable_name` function, and then
-// computes a hash of this stable name.
+// computes a hash of this stable name. For instance, `foo.llvm.1234` would have
+// the same hash as `foo.llvm.5678.
 inline stable_hash stable_hash_name(StringRef Name) {
   return xxh3_64bits(get_stable_name(Name));
 }

llvm/lib/CodeGen/MachineStableHash.cpp

@@ -84,21 +84,21 @@ stable_hash llvm::stableHashValue(const MachineOperand &MO) {
   }
 
   case MachineOperand::MO_MachineBasicBlock:
-    StableHashBailingMachineBasicBlock++;
+    ++StableHashBailingMachineBasicBlock;
     return 0;
   case MachineOperand::MO_ConstantPoolIndex:
-    StableHashBailingConstantPoolIndex++;
+    ++StableHashBailingConstantPoolIndex;
     return 0;
   case MachineOperand::MO_BlockAddress:
-    StableHashBailingBlockAddress++;
+    ++StableHashBailingBlockAddress;
     return 0;
   case MachineOperand::MO_Metadata:
-    StableHashBailingMetadataUnsupported++;
+    ++StableHashBailingMetadataUnsupported;
     return 0;
   case MachineOperand::MO_GlobalAddress: {
     const GlobalValue *GV = MO.getGlobal();
     if (!GV->hasName()) {
-      StableHashBailingGlobalAddress++;
+      ++StableHashBailingGlobalAddress;
       return 0;
     }
     auto Name = GV->getName();
@@ -110,7 +110,7 @@ stable_hash llvm::stableHashValue(const MachineOperand &MO) {
     if (const char *Name = MO.getTargetIndexName())
       return stable_hash_combine(MO.getType(), MO.getTargetFlags(),
                                  stable_hash_name(Name), MO.getOffset());
-    StableHashBailingTargetIndexNoName++;
+    ++StableHashBailingTargetIndexNoName;
     return 0;
   }
 

llvm/unittests/MIR/MachineStableHashTest.cpp

@@ -134,10 +134,10 @@ body:             |
   auto *MF3 = MMI.getMachineFunction(*M->getFunction("f3"));
   auto *MF4 = MMI.getMachineFunction(*M->getFunction("f4"));
 
-  // Expect the suffix, `.llvm.{number}` to be ignored.
-  EXPECT_EQ(stableHashValue(*MF1), stableHashValue(*MF2));
-  // Expect the suffix, `.__uniq.{number}` to be ignored.
-  EXPECT_EQ(stableHashValue(*MF1), stableHashValue(*MF3));
+  EXPECT_EQ(stableHashValue(*MF1), stableHashValue(*MF2))
+      << "Expect the suffix, `.llvm.{number}` to be ignored.";
+  EXPECT_EQ(stableHashValue(*MF1), stableHashValue(*MF3))
+      << "Expect the suffix, `.__uniq.{number}` to be ignored.";
   // Do not ignore `.invalid.{number}`.
   EXPECT_NE(stableHashValue(*MF1), stableHashValue(*MF4));
 }