return true;

Author: Thorsten Schütt

llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h

@@ -150,10 +150,6 @@ class CombinerHelper {
   /// is a legal integer constant type on the target.
   bool isConstantLegalOrBeforeLegalizer(const LLT Ty) const;
 
-  /// \return true if the combine is running prior to legalization, or if \p Ty
-  /// is a legal undef type on the target.
-  bool isUndefLegalOrBeforeLegalizer(const LLT Ty) const;
-
   /// MachineRegisterInfo::replaceRegWith() and inform the observer of the changes
   void replaceRegWith(MachineRegisterInfo &MRI, Register FromReg, Register ToReg) const;
 

llvm/include/llvm/Target/GlobalISel/Combine.td

@@ -1861,7 +1861,7 @@ def anyext_undef: GICombineRule<
    (defs root:$root),
    (match (G_IMPLICIT_DEF $undef),
           (G_ANYEXT $root, $undef):$Aext,
-   [{ return Helper.isUndefLegalOrBeforeLegalizer(MRI.getType(${Aext}->getOperand(0).getReg())); }]),
+   [{ return true; }]),
    (apply [{ Helper.replaceInstWithUndef(*${Aext}); }])>;
 
 def zext_undef: GICombineRule<

llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp

@@ -171,10 +171,6 @@ bool CombinerHelper::isConstantLegalOrBeforeLegalizer(const LLT Ty) const {
          isLegal({TargetOpcode::G_CONSTANT, {EltTy}});
 }
 
-bool CombinerHelper::isUndefLegalOrBeforeLegalizer(const LLT Ty) const {
-  return isPreLegalize() || isLegal({TargetOpcode::G_IMPLICIT_DEF, {Ty}});
-}
-
 void CombinerHelper::replaceRegWith(MachineRegisterInfo &MRI, Register FromReg,
                                     Register ToReg) const {
   Observer.changingAllUsesOfReg(MRI, FromReg);