99 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			99 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C++
		
	
	
	
| //===-- WebAssemblyRegNumbering.cpp - Register Numbering ------------------===//
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| //
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| //                     The LLVM Compiler Infrastructure
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| //
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| // This file is distributed under the University of Illinois Open Source
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| // License. See LICENSE.TXT for details.
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| //
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| //===----------------------------------------------------------------------===//
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| ///
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| /// \file
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| /// \brief This file implements a pass which assigns WebAssembly register
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| /// numbers for CodeGen virtual registers.
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| ///
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| //===----------------------------------------------------------------------===//
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| 
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| #include "WebAssembly.h"
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| #include "MCTargetDesc/WebAssemblyMCTargetDesc.h"
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| #include "WebAssemblyMachineFunctionInfo.h"
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| #include "WebAssemblySubtarget.h"
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| #include "llvm/ADT/SCCIterator.h"
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| #include "llvm/CodeGen/MachineFunction.h"
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| #include "llvm/CodeGen/MachineInstrBuilder.h"
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| #include "llvm/CodeGen/MachineLoopInfo.h"
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| #include "llvm/CodeGen/MachineRegisterInfo.h"
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| #include "llvm/CodeGen/Passes.h"
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| #include "llvm/Support/Debug.h"
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| #include "llvm/Support/raw_ostream.h"
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| using namespace llvm;
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| 
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| #define DEBUG_TYPE "wasm-reg-numbering"
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| 
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| namespace {
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| class WebAssemblyRegNumbering final : public MachineFunctionPass {
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|   const char *getPassName() const override {
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|     return "WebAssembly Register Numbering";
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|   }
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| 
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|   void getAnalysisUsage(AnalysisUsage &AU) const override {
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|     AU.setPreservesCFG();
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|     MachineFunctionPass::getAnalysisUsage(AU);
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|   }
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| 
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|   bool runOnMachineFunction(MachineFunction &MF) override;
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| 
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| public:
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|   static char ID; // Pass identification, replacement for typeid
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|   WebAssemblyRegNumbering() : MachineFunctionPass(ID) {}
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| };
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| } // end anonymous namespace
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| 
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| char WebAssemblyRegNumbering::ID = 0;
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| FunctionPass *llvm::createWebAssemblyRegNumbering() {
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|   return new WebAssemblyRegNumbering();
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| }
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| 
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| bool WebAssemblyRegNumbering::runOnMachineFunction(MachineFunction &MF) {
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|   DEBUG(dbgs() << "********** Register Numbering **********\n"
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|                   "********** Function: "
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|                << MF.getName() << '\n');
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| 
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|   WebAssemblyFunctionInfo &MFI = *MF.getInfo<WebAssemblyFunctionInfo>();
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|   MachineRegisterInfo &MRI = MF.getRegInfo();
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| 
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|   MFI.initWARegs();
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| 
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|   // WebAssembly argument registers are in the same index space as local
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|   // variables. Assign the numbers for them first.
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|   for (MachineBasicBlock &MBB : MF) {
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|     for (MachineInstr &MI : MBB) {
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|       switch (MI.getOpcode()) {
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|       case WebAssembly::ARGUMENT_I32:
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|       case WebAssembly::ARGUMENT_I64:
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|       case WebAssembly::ARGUMENT_F32:
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|       case WebAssembly::ARGUMENT_F64:
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|         MFI.setWAReg(MI.getOperand(0).getReg(), MI.getOperand(1).getImm());
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|         break;
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|       default:
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|         break;
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|       }
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|     }
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|   }
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| 
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|   // Then assign regular WebAssembly registers for all remaining used
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|   // virtual registers.
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|   unsigned NumArgRegs = MFI.getParams().size();
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|   unsigned NumVRegs = MF.getRegInfo().getNumVirtRegs();
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|   unsigned CurReg = 0;
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|   for (unsigned VRegIdx = 0; VRegIdx < NumVRegs; ++VRegIdx) {
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|     unsigned VReg = TargetRegisterInfo::index2VirtReg(VRegIdx);
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|     // Skip unused registers.
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|     if (MRI.use_empty(VReg))
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|       continue;
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|     if (MFI.getWAReg(VReg) == WebAssemblyFunctionInfo::UnusedReg)
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|       MFI.setWAReg(VReg, NumArgRegs + CurReg++);
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|   }
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| 
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|   return true;
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| }
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