lib/Target/Alpha/AlphaBranchSelector.cpp

   1 //===-- AlphaBranchSelector.cpp - Convert Pseudo branchs ----------*- C++ -*-=//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // Replace Pseudo COND_BRANCH_* with their appropriate real branch
  11 // Simplified version of the PPC Branch Selector
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "Alpha.h"
  16 #include "AlphaInstrInfo.h"
  17 #include "llvm/CodeGen/MachineFunctionPass.h"
  18 #include "llvm/Support/Compiler.h"
  19 #include "llvm/Target/TargetMachine.h"
  20 #include "llvm/Target/TargetAsmInfo.h"
  21 using namespace llvm;
  22
  23 namespace {
  24   struct VISIBILITY_HIDDEN AlphaBSel : public MachineFunctionPass {
  25     static char ID;
  26     AlphaBSel() : MachineFunctionPass(&ID) {}
  27
  28     virtual bool runOnMachineFunction(MachineFunction &Fn);
  29
  30     virtual const char *getPassName() const {
  31       return "Alpha Branch Selection";
  32     }
  33   };
  34   char AlphaBSel::ID = 0;
  35 }
  36
  37 /// createAlphaBranchSelectionPass - returns an instance of the Branch Selection
  38 /// Pass
  39 ///
  40 FunctionPass *llvm::createAlphaBranchSelectionPass() {
  41   return new AlphaBSel();
  42 }
  43
  44 bool AlphaBSel::runOnMachineFunction(MachineFunction &Fn) {
  45
  46   for (MachineFunction::iterator MFI = Fn.begin(), E = Fn.end(); MFI != E;
  47        ++MFI) {
  48     MachineBasicBlock *MBB = MFI;
  49
  50     for (MachineBasicBlock::iterator MBBI = MBB->begin(), EE = MBB->end();
  51          MBBI != EE; ++MBBI) {
  52       if (MBBI->getOpcode() == Alpha::COND_BRANCH_I ||
  53           MBBI->getOpcode() == Alpha::COND_BRANCH_F) {
  54
  55         // condbranch operands:
  56         // 0. bc opcode
  57         // 1. reg
  58         // 2. target MBB
  59         const TargetInstrInfo *TII = Fn.getTarget().getInstrInfo();
  60         MBBI->setDesc(TII->get(MBBI->getOperand(0).getImm()));
  61       }
  62     }
  63   }
  64
  65   return true;
  66 }
  67