[llvm] Fix the usage issue of getRegMask. (PR #141215)

[via llvm-commits]

https://github.com/wdx727 created https://github.com/llvm/llvm-project/pull/141215

In the process of determining whether two MachineOperands are equal and calculating the hash of a MachineOperand, both MO_RegisterMask and MO_RegisterLiveOut types were uniformly handled. However, when the type is MO_RegisterLiveOut, calling getRegMask() triggers an assertion failure. This PR addresses this issue.

>From ad8cc686cc2fef6a32a832a6cf9258b0706b058a Mon Sep 17 00:00:00 2001
From: wudexin <wudexin at kuaishou.com>
Date: Fri, 23 May 2025 16:58:05 +0800
Subject: [PATCH] Fix the usage issue of getRegMask.

---
 llvm/lib/CodeGen/MachineOperand.cpp    | 6 +++---
 llvm/lib/CodeGen/MachineStableHash.cpp | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/llvm/lib/CodeGen/MachineOperand.cpp b/llvm/lib/CodeGen/MachineOperand.cpp
index 0d251697f2567..0bc6fde857064 100644
--- a/llvm/lib/CodeGen/MachineOperand.cpp
+++ b/llvm/lib/CodeGen/MachineOperand.cpp
@@ -350,8 +350,8 @@ bool MachineOperand::isIdenticalTo(const MachineOperand &Other) const {
   case MachineOperand::MO_RegisterMask:
   case MachineOperand::MO_RegisterLiveOut: {
     // Shallow compare of the two RegMasks
-    const uint32_t *RegMask = getRegMask();
-    const uint32_t *OtherRegMask = Other.getRegMask();
+    const uint32_t *RegMask = isRegMask() ? getRegMask() : getRegLiveOut();
+    const uint32_t *OtherRegMask = isRegMask() ? Other.getRegMask() : Other.getRegLiveOut();
     if (RegMask == OtherRegMask)
       return true;
 
@@ -421,7 +421,7 @@ hash_code llvm::hash_value(const MachineOperand &MO) {
     if (const MachineFunction *MF = getMFIfAvailable(MO)) {
       const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
       unsigned RegMaskSize = MachineOperand::getRegMaskSize(TRI->getNumRegs());
-      const uint32_t *RegMask = MO.getRegMask();
+      const uint32_t *RegMask = MO.isRegMask() ? MO.getRegMask() : MO.getRegLiveOut();
       std::vector<stable_hash> RegMaskHashes(RegMask, RegMask + RegMaskSize);
       return hash_combine(MO.getType(), MO.getTargetFlags(),
                           stable_hash_combine(RegMaskHashes));
diff --git a/llvm/lib/CodeGen/MachineStableHash.cpp b/llvm/lib/CodeGen/MachineStableHash.cpp
index 9d56696079478..6e57f734535aa 100644
--- a/llvm/lib/CodeGen/MachineStableHash.cpp
+++ b/llvm/lib/CodeGen/MachineStableHash.cpp
@@ -136,7 +136,7 @@ stable_hash llvm::stableHashValue(const MachineOperand &MO) {
           const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
           unsigned RegMaskSize =
               MachineOperand::getRegMaskSize(TRI->getNumRegs());
-          const uint32_t *RegMask = MO.getRegMask();
+          const uint32_t *RegMask = MO.isRegMask() ? MO.getRegMask() : MO.getRegLiveOut();
           std::vector<llvm::stable_hash> RegMaskHashes(RegMask,
                                                        RegMask + RegMaskSize);
           return stable_hash_combine(MO.getType(), MO.getTargetFlags(),