[InstCombine] Remove unused function createInstructionCombiningPass

[kazu]

Summary

The last use was removed by:

commit 934c82d31801e65aa3bbe99a0e64f903621c2e04
Author: Florian Hahn <[e-mail]>
Date:   Fri Feb 24 13:39:32 2023 +0100

Once I remove createInstructionCombiningPass, then:

InstructionCombiningPass::InstructionCombiningPass(unsigned MaxIterations)

becomes unused. Once I remove that:

InstructionCombiningPass::MaxIterations is always initialized with
InstCombineDefaultMaxIterations, so this patch does the constant
propagation and removes InstructionCombiningPass::MaxIterations as
well.

[nikic]

LG

llvm/include/llvm/Transforms/InstCombine/InstCombine.h

 };
 
 /// The legacy pass manager's instcombine pass.
 ///
 /// This is a basic whole-function wrapper around the instcombine utility. It
 /// will try to combine all instructions in the function.
 class InstructionCombiningPass : public FunctionPass {
   InstructionWorklist Worklist;
-  const unsigned MaxIterations;
 
 public:
   static char ID; // Pass identification, replacement for typeid
 
   explicit InstructionCombiningPass();
-  explicit InstructionCombiningPass(unsigned MaxIterations);
 
   void getAnalysisUsage(AnalysisUsage &AU) const override;
   bool runOnFunction(Function &F) override;
 };
 
 //===----------------------------------------------------------------------===//
 //
 // InstructionCombining - Combine instructions to form fewer, simple
 // instructions. This pass does not modify the CFG, and has a tendency to make
 // instructions dead, so a subsequent DCE pass is useful.
 //
 // This pass combines things like:
 //    %Y = add int 1, %X
 //    %Z = add int 1, %Y
 // into:
 //    %Z = add int 2, %X
 //
 FunctionPass *createInstructionCombiningPass();
-FunctionPass *createInstructionCombiningPass(unsigned MaxIterations);
 }
 
 #undef DEBUG_TYPE
 
 #endif

llvm/lib/Transforms/InstCombine/InstructionCombining.cpp

bool InstructionCombiningPass::runOnFunction(Function &F) {
   ProfileSummaryInfo *PSI =
       &getAnalysis<ProfileSummaryInfoWrapperPass>().getPSI();
   BlockFrequencyInfo *BFI =
       (PSI && PSI->hasProfileSummary()) ?
       &getAnalysis<LazyBlockFrequencyInfoPass>().getBFI() :
       nullptr;
 
   return combineInstructionsOverFunction(F, Worklist, AA, AC, TLI, TTI, DT, ORE,
-                                         BFI, PSI, MaxIterations, LI);
+                                         BFI, PSI,
+                                         InstCombineDefaultMaxIterations, LI);
 }
 
 char InstructionCombiningPass::ID = 0;
 
-InstructionCombiningPass::InstructionCombiningPass()
-    : FunctionPass(ID), MaxIterations(InstCombineDefaultMaxIterations) {
-  initializeInstructionCombiningPassPass(*PassRegistry::getPassRegistry());
-}
-
-InstructionCombiningPass::InstructionCombiningPass(unsigned MaxIterations)
-    : FunctionPass(ID), MaxIterations(MaxIterations) {
+InstructionCombiningPass::InstructionCombiningPass() : FunctionPass(ID) {
   initializeInstructionCombiningPassPass(*PassRegistry::getPassRegistry());
 }
 
 INITIALIZE_PASS_BEGIN(InstructionCombiningPass, "instcombine",
                       "Combine redundant instructions", false, false)
 INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)

 // Initialization Routines
 void llvm::initializeInstCombine(PassRegistry &Registry) {
   initializeInstructionCombiningPassPass(Registry);
 }
 
 FunctionPass *llvm::createInstructionCombiningPass() {
   return new InstructionCombiningPass();
 }
-
-FunctionPass *llvm::createInstructionCombiningPass(unsigned MaxIterations) {
-  return new InstructionCombiningPass(MaxIterations);
-}