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/Target/TargetMachine.h"
  19 #include "llvm/MC/MCAsmInfo.h"
  20 using namespace llvm;
  21
  22 namespace {
  23   struct AlphaBSel : public MachineFunctionPass {
  24     static char ID;
  25     AlphaBSel() : MachineFunctionPass(ID) {}
  26
  27     virtual bool runOnMachineFunction(MachineFunction &Fn);
  28
  29     virtual const char *getPassName() const {
  30       return "Alpha Branch Selection";
  31     }
  32   };
  33   char AlphaBSel::ID = 0;
  34 }
  35
  36 /// createAlphaBranchSelectionPass - returns an instance of the Branch Selection
  37 /// Pass
  38 ///
  39 FunctionPass *llvm::createAlphaBranchSelectionPass() {
  40   return new AlphaBSel();
  41 }
  42
  43 bool AlphaBSel::runOnMachineFunction(MachineFunction &Fn) {
  44
  45   for (MachineFunction::iterator MFI = Fn.begin(), E = Fn.end(); MFI != E;
  46        ++MFI) {
  47     MachineBasicBlock *MBB = MFI;
  48
  49     for (MachineBasicBlock::iterator MBBI = MBB->begin(), EE = MBB->end();
  50          MBBI != EE; ++MBBI) {
  51       if (MBBI->getOpcode() == Alpha::COND_BRANCH_I ||
  52           MBBI->getOpcode() == Alpha::COND_BRANCH_F) {
  53
  54         // condbranch operands:
  55         // 0. bc opcode
  56         // 1. reg
  57         // 2. target MBB
  58         const TargetInstrInfo *TII = Fn.getTarget().getInstrInfo();
  59         MBBI->setDesc(TII->get(MBBI->getOperand(0).getImm()));
  60       }
  61     }
  62   }
  63
  64   return true;
  65 }
  66