[MC] Check if register is non-null before calling isSubRegisterEq (NFCI)

D151036 adds an assertions that prohibits iterating over sub- and super-registers of a null register. This is already the case when iterating over register units of a null register, and worked by accident for sub- and super-registers. Reviewed By: Amir Differential Revision: https://reviews.llvm.org/D151285
llvm · May 25, 2023 · ee1d5f6 · ee1d5f6
1 parent 2517497
commit ee1d5f6
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Showing 2 changed files with 2 additions and 2 deletions.
diff --git a/bolt/lib/Core/MCPlusBuilder.cpp b/bolt/lib/Core/MCPlusBuilder.cpp
@@ -425,7 +425,7 @@ bool MCPlusBuilder::hasDefOfPhysReg(const MCInst &MI, unsigned Reg) const {
 bool MCPlusBuilder::hasUseOfPhysReg(const MCInst &MI, unsigned Reg) const {
   const MCInstrDesc &InstInfo = Info->get(MI.getOpcode());
   for (int I = InstInfo.NumDefs; I < InstInfo.NumOperands; ++I)
-    if (MI.getOperand(I).isReg() &&
+    if (MI.getOperand(I).isReg() && MI.getOperand(I).getReg() &&
         RegInfo->isSubRegisterEq(Reg, MI.getOperand(I).getReg()))
       return true;
   for (MCPhysReg ImplicitUse : InstInfo.implicit_uses()) {

diff --git a/llvm/lib/MC/MCInstrDesc.cpp b/llvm/lib/MC/MCInstrDesc.cpp
@@ -40,7 +40,7 @@ bool MCInstrDesc::hasImplicitDefOfPhysReg(unsigned Reg,
 bool MCInstrDesc::hasDefOfPhysReg(const MCInst &MI, unsigned Reg,
                                   const MCRegisterInfo &RI) const {
   for (int i = 0, e = NumDefs; i != e; ++i)
-    if (MI.getOperand(i).isReg() &&
+    if (MI.getOperand(i).isReg() && MI.getOperand(i).getReg() &&
         RI.isSubRegisterEq(Reg, MI.getOperand(i).getReg()))
       return true;
   if (variadicOpsAreDefs())