lib/CodeGen/LLVMTargetMachine.cpp

   1 //===-- LLVMTargetMachine.cpp - Implement the LLVMTargetMachine class -----===//
   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 // This file implements the LLVMTargetMachine class.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Target/TargetMachine.h"
  15 #include "llvm/PassManager.h"
  16 #include "llvm/Pass.h"
  17 #include "llvm/Assembly/PrintModulePass.h"
  18 #include "llvm/Analysis/LoopPass.h"
  19 #include "llvm/CodeGen/Passes.h"
  20 #include "llvm/CodeGen/GCStrategy.h"
  21 #include "llvm/Target/TargetOptions.h"
  22 #include "llvm/Target/TargetAsmInfo.h"
  23 #include "llvm/Transforms/Scalar.h"
  24 #include "llvm/Support/CommandLine.h"
  25 #include "llvm/Support/raw_ostream.h"
  26 using namespace llvm;
  27
  28 static cl::opt<bool> PrintLSR("print-lsr-output", cl::Hidden,
  29     cl::desc("Print LLVM IR produced by the loop-reduce pass"));
  30 static cl::opt<bool> PrintISelInput("print-isel-input", cl::Hidden,
  31     cl::desc("Print LLVM IR input to isel pass"));
  32 static cl::opt<bool> PrintEmittedAsm("print-emitted-asm", cl::Hidden,
  33     cl::desc("Dump emitter generated instructions as assembly"));
  34 static cl::opt<bool> PrintGCInfo("print-gc", cl::Hidden,
  35     cl::desc("Dump garbage collector data"));
  36
  37 // Hidden options to help debugging
  38 static cl::opt<bool>
  39 EnableSinking("enable-sinking", cl::init(false), cl::Hidden,
  40               cl::desc("Perform sinking on machine code"));
  41 static cl::opt<bool>
  42 EnableLICM("machine-licm",
  43            cl::init(false), cl::Hidden,
  44            cl::desc("Perform loop-invariant code motion on machine code"));
  45
  46 // When this works it will be on by default.
  47 static cl::opt<bool>
  48 DisablePostRAScheduler("disable-post-RA-scheduler",
  49                        cl::desc("Disable scheduling after register allocation"),
  50                        cl::init(true));
  51
  52 FileModel::Model
  53 LLVMTargetMachine::addPassesToEmitFile(PassManagerBase &PM,
  54                                        raw_ostream &Out,
  55                                        CodeGenFileType FileType,
  56                                        bool Fast) {
  57   // Add common CodeGen passes.
  58   if (addCommonCodeGenPasses(PM, Fast))
  59     return FileModel::Error;
  60
  61   // Fold redundant debug labels.
  62   PM.add(createDebugLabelFoldingPass());
  63
  64   if (PrintMachineCode)
  65     PM.add(createMachineFunctionPrinterPass(cerr));
  66
  67   if (addPreEmitPass(PM, Fast) && PrintMachineCode)
  68     PM.add(createMachineFunctionPrinterPass(cerr));
  69
  70   if (!Fast && !OptimizeForSize)
  71     PM.add(createLoopAlignerPass());
  72
  73   switch (FileType) {
  74   default:
  75     break;
  76   case TargetMachine::AssemblyFile:
  77     if (addAssemblyEmitter(PM, Fast, Out))
  78       return FileModel::Error;
  79     return FileModel::AsmFile;
  80   case TargetMachine::ObjectFile:
  81     if (getMachOWriterInfo())
  82       return FileModel::MachOFile;
  83     else if (getELFWriterInfo())
  84       return FileModel::ElfFile;
  85   }
  86
  87   return FileModel::Error;
  88 }
  89
  90 /// addPassesToEmitFileFinish - If the passes to emit the specified file had to
  91 /// be split up (e.g., to add an object writer pass), this method can be used to
  92 /// finish up adding passes to emit the file, if necessary.
  93 bool LLVMTargetMachine::addPassesToEmitFileFinish(PassManagerBase &PM,
  94                                                   MachineCodeEmitter *MCE,
  95                                                   bool Fast) {
  96   if (MCE)
  97     addSimpleCodeEmitter(PM, Fast, PrintEmittedAsm, *MCE);
  98
  99   PM.add(createGCInfoDeleter());
 100
 101   // Delete machine code for this function
 102   PM.add(createMachineCodeDeleter());
 103
 104   return false; // success!
 105 }
 106
 107 /// addPassesToEmitMachineCode - Add passes to the specified pass manager to
 108 /// get machine code emitted.  This uses a MachineCodeEmitter object to handle
 109 /// actually outputting the machine code and resolving things like the address
 110 /// of functions.  This method should returns true if machine code emission is
 111 /// not supported.
 112 ///
 113 bool LLVMTargetMachine::addPassesToEmitMachineCode(PassManagerBase &PM,
 114                                                    MachineCodeEmitter &MCE,
 115                                                    bool Fast) {
 116   // Add common CodeGen passes.
 117   if (addCommonCodeGenPasses(PM, Fast))
 118     return true;
 119
 120   if (addPreEmitPass(PM, Fast) && PrintMachineCode)
 121     PM.add(createMachineFunctionPrinterPass(cerr));
 122
 123   addCodeEmitter(PM, Fast, PrintEmittedAsm, MCE);
 124
 125   PM.add(createGCInfoDeleter());
 126
 127   // Delete machine code for this function
 128   PM.add(createMachineCodeDeleter());
 129
 130   return false; // success!
 131 }
 132
 133 /// addCommonCodeGenPasses - Add standard LLVM codegen passes used for
 134 /// both emitting to assembly files or machine code output.
 135 ///
 136 bool LLVMTargetMachine::addCommonCodeGenPasses(PassManagerBase &PM, bool Fast) {
 137   // Standard LLVM-Level Passes.
 138
 139   // Run loop strength reduction before anything else.
 140   if (!Fast) {
 141     PM.add(createLoopStrengthReducePass(getTargetLowering()));
 142     if (PrintLSR)
 143       PM.add(new PrintFunctionPass("\n\n*** Code after LSR ***\n", &cerr));
 144   }
 145
 146   PM.add(createGCLoweringPass());
 147
 148   if (!getTargetAsmInfo()->doesSupportExceptionHandling())
 149     PM.add(createLowerInvokePass(getTargetLowering()));
 150
 151   // Make sure that no unreachable blocks are instruction selected.
 152   PM.add(createUnreachableBlockEliminationPass());
 153
 154   if (!Fast)
 155     PM.add(createCodeGenPreparePass(getTargetLowering()));
 156
 157   if (PrintISelInput)
 158     PM.add(new PrintFunctionPass("\n\n*** Final LLVM Code input to ISel ***\n",
 159                                  &cerr));
 160
 161   // Standard Lower-Level Passes.
 162
 163   // Ask the target for an isel.
 164   if (addInstSelector(PM, Fast))
 165     return true;
 166
 167   // Print the instruction selected machine code...
 168   if (PrintMachineCode)
 169     PM.add(createMachineFunctionPrinterPass(cerr));
 170
 171   if (EnableLICM)
 172     PM.add(createMachineLICMPass());
 173
 174   if (EnableSinking)
 175     PM.add(createMachineSinkingPass());
 176
 177   // Run pre-ra passes.
 178   if (addPreRegAlloc(PM, Fast) && PrintMachineCode)
 179     PM.add(createMachineFunctionPrinterPass(cerr));
 180
 181   // Perform register allocation.
 182   PM.add(createRegisterAllocator());
 183
 184   // Perform stack slot coloring.
 185   if (!Fast)
 186     PM.add(createStackSlotColoringPass());
 187
 188   if (PrintMachineCode)  // Print the register-allocated code
 189     PM.add(createMachineFunctionPrinterPass(cerr));
 190
 191   // Run post-ra passes.
 192   if (addPostRegAlloc(PM, Fast) && PrintMachineCode)
 193     PM.add(createMachineFunctionPrinterPass(cerr));
 194
 195   if (PrintMachineCode)
 196     PM.add(createMachineFunctionPrinterPass(cerr));
 197
 198   PM.add(createLowerSubregsPass());
 199
 200   if (PrintMachineCode)  // Print the subreg lowered code
 201     PM.add(createMachineFunctionPrinterPass(cerr));
 202
 203   // Insert prolog/epilog code.  Eliminate abstract frame index references...
 204   PM.add(createPrologEpilogCodeInserter());
 205
 206   if (PrintMachineCode)
 207     PM.add(createMachineFunctionPrinterPass(cerr));
 208
 209   // Second pass scheduler.
 210   if (!Fast && !DisablePostRAScheduler)
 211     PM.add(createPostRAScheduler());
 212
 213   // Branch folding must be run after regalloc and prolog/epilog insertion.
 214   if (!Fast)
 215     PM.add(createBranchFoldingPass(getEnableTailMergeDefault()));
 216
 217   PM.add(createGCMachineCodeAnalysisPass());
 218
 219   if (PrintMachineCode)
 220     PM.add(createMachineFunctionPrinterPass(cerr));
 221
 222   if (PrintGCInfo)
 223     PM.add(createGCInfoPrinter(*cerr));
 224
 225   return false;
 226 }