[PPC] Replace PPCMergeStringPool with GlobalMerge for Linux (#114850)

Enable merging all constants without looking at use in GlobalMerge by
default to replace PPCMergeStringPool pass on Linux.

Author: syzaara

llvm/lib/CodeGen/GlobalMerge.cpp

@@ -79,6 +79,7 @@
 #include "llvm/IR/GlobalValue.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/Instruction.h"
+#include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Type.h"
 #include "llvm/IR/Use.h"
@@ -632,10 +633,13 @@ void GlobalMergeImpl::setMustKeepGlobalVariables(Module &M) {
   for (Function &F : M) {
     for (BasicBlock &BB : F) {
       Instruction *Pad = BB.getFirstNonPHI();
-      if (!Pad->isEHPad())
+      auto *II = dyn_cast<IntrinsicInst>(Pad);
+      if (!Pad->isEHPad() &&
+          !(II && II->getIntrinsicID() == Intrinsic::eh_typeid_for))
         continue;
 
-      // Keep globals used by landingpads and catchpads.
+      // Keep globals used by landingpads, catchpads,
+      // or intrinsics that require a plain global.
       for (const Use &U : Pad->operands()) {
         if (const GlobalVariable *GV =
                 dyn_cast<GlobalVariable>(U->stripPointerCasts()))

llvm/lib/Target/PowerPC/CMakeLists.txt

@@ -41,7 +41,6 @@ add_llvm_target(PowerPCCodeGen
   PPCMachineFunctionInfo.cpp
   PPCMachineScheduler.cpp
   PPCMacroFusion.cpp
-  PPCMergeStringPool.cpp
   PPCMIPeephole.cpp
   PPCRegisterInfo.cpp
   PPCSubtarget.cpp

llvm/lib/Target/PowerPC/PPC.h

@@ -53,7 +53,6 @@ class ModulePass;
   FunctionPass *createPPCPreEmitPeepholePass();
   FunctionPass *createPPCExpandAtomicPseudoPass();
   FunctionPass *createPPCCTRLoopsPass();
-  ModulePass *createPPCMergeStringPoolPass();
   void LowerPPCMachineInstrToMCInst(const MachineInstr *MI, MCInst &OutMI,
                                     AsmPrinter &AP);
   bool LowerPPCMachineOperandToMCOperand(const MachineOperand &MO,
@@ -79,7 +78,6 @@ class ModulePass;
   void initializePPCExpandAtomicPseudoPass(PassRegistry &);
   void initializePPCCTRLoopsPass(PassRegistry &);
   void initializePPCDAGToDAGISelLegacyPass(PassRegistry &);
-  void initializePPCMergeStringPoolPass(PassRegistry &);
 
   extern char &PPCVSXFMAMutateID;