CodeGen/LLVMTargetMachine: Refactor ISel pass construction; NFCI

- Move ISel (and pre-isel) pass construction into TargetPassConfig
- Extract AsmPrinter construction into a helper function

Putting the ISel code into TargetPassConfig seems a lot more natural and
both changes together make make it easier to build custom pipelines
involving .mir in an upcoming commit. This moves MachineModuleInfo to an
earlier place in the pass pipeline which shouldn't have any effect.

llvm-svn: 304754

6 files changed, 123 insertions, 102 deletions

diff --git a/llvm/include/llvm/CodeGen/TargetPassConfig.h b/llvm/include/llvm/CodeGen/TargetPassConfig.h
index fcf1937..c109b74 100644
--- a/llvm/include/llvm/CodeGen/TargetPassConfig.h
+++ b/llvm/include/llvm/CodeGen/TargetPassConfig.h
@@ -119,6 +119,10 @@ protected:
   /// callers.
   bool RequireCodeGenSCCOrder;
 
+  /// Add the actual instruction selection passes. This does not include
+  /// preparation passes on IR.
+  bool addCoreISelPasses();
+
 public:
   TargetPassConfig(LLVMTargetMachine &TM, PassManagerBase &pm);
   // Dummy constructor.
@@ -206,6 +210,13 @@ public:
   /// has not be overriden on the command line with '-regalloc=...'
   bool usingDefaultRegAlloc() const;
 
+  /// High level function that adds all passes necessary to go from llvm IR
+  /// representation to the MI representation.
+  /// Adds IR based lowering and target specific optimization passes and finally
+  /// the core instruction selection passes.
+  /// \returns true if an error occured, false otherwise.
+  bool addISelPasses();
+
   /// Add common target configurable passes that perform LLVM IR to IR
   /// transforms following machine independent optimization.
   virtual void addIRPasses();
diff --git a/llvm/include/llvm/Target/TargetMachine.h b/llvm/include/llvm/Target/TargetMachine.h
index ed39079..d68bd35 100644
--- a/llvm/include/llvm/Target/TargetMachine.h
+++ b/llvm/include/llvm/Target/TargetMachine.h
@@ -305,6 +305,11 @@ public:
   /// remove this at some point and always enable the verifier when
   /// EXPENSIVE_CHECKS is enabled.
   virtual bool isMachineVerifierClean() const { return true; }
+
+  /// \brief Adds an AsmPrinter pass to the pipeline that prints assembly or
+  /// machine code from the MI representation.
+  bool addAsmPrinter(PassManagerBase &PM, raw_pwrite_stream &Out,
+                     CodeGenFileType FileTYpe, MCContext &Context);
 };
 
 } // end namespace llvm
diff --git a/llvm/lib/CodeGen/LLVMTargetMachine.cpp b/llvm/lib/CodeGen/LLVMTargetMachine.cpp
index be3b258..66e6e7a 100644
--- a/llvm/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/llvm/lib/CodeGen/LLVMTargetMachine.cpp
@@ -35,17 +35,6 @@
 #include "llvm/Transforms/Scalar.h"
 using namespace llvm;
 
-// Enable or disable FastISel. Both options are needed, because
-// FastISel is enabled by default with -fast, and we wish to be
-// able to enable or disable fast-isel independently from -O0.
-static cl::opt<cl::boolOrDefault>
-EnableFastISelOption("fast-isel", cl::Hidden,
-  cl::desc("Enable the \"fast\" instruction selector"));
-
-static cl::opt<cl::boolOrDefault>
-    EnableGlobalISel("global-isel", cl::Hidden,
-                     cl::desc("Enable the \"global\" instruction selector"));
-
 void LLVMTargetMachine::initAsmInfo() {
   MRI = TheTarget.createMCRegInfo(getTargetTriple().str());
   MII = TheTarget.createMCInstrInfo();
@@ -117,99 +106,23 @@ addPassesToGenerateCode(LLVMTargetMachine *TM, PassManagerBase &PM,
   // Set PassConfig options provided by TargetMachine.
   PassConfig->setDisableVerify(DisableVerify);
   PM.add(PassConfig);
-
-  // When in emulated TLS mode, add the LowerEmuTLS pass.
-  if (TM->Options.EmulatedTLS)
-    PM.add(createLowerEmuTLSPass());
-
-  PM.add(createPreISelIntrinsicLoweringPass());
-
-  // Add internal analysis passes from the target machine.
-  PM.add(createTargetTransformInfoWrapperPass(TM->getTargetIRAnalysis()));
-
-  PassConfig->addIRPasses();
-
-  PassConfig->addCodeGenPrepare();
-
-  PassConfig->addPassesToHandleExceptions();
-
-  PassConfig->addISelPrepare();
-
   MachineModuleInfo *MMI = new MachineModuleInfo(TM);
   MMI->setMachineFunctionInitializer(MFInitializer);
   PM.add(MMI);
 
-  // Enable FastISel with -fast, but allow that to be overridden.
-  TM->setO0WantsFastISel(EnableFastISelOption != cl::BOU_FALSE);
-  if (EnableFastISelOption == cl::BOU_TRUE ||
-      (TM->getOptLevel() == CodeGenOpt::None &&
-       TM->getO0WantsFastISel()))
-    TM->setFastISel(true);
-
-  // Ask the target for an isel.
-  // Enable GlobalISel if the target wants to, but allow that to be overriden.
-  if (EnableGlobalISel == cl::BOU_TRUE || (EnableGlobalISel == cl::BOU_UNSET &&
-                                           PassConfig->isGlobalISelEnabled())) {
-    if (PassConfig->addIRTranslator())
-      return nullptr;
-
-    PassConfig->addPreLegalizeMachineIR();
-
-    if (PassConfig->addLegalizeMachineIR())
-      return nullptr;
-
-    // Before running the register bank selector, ask the target if it
-    // wants to run some passes.
-    PassConfig->addPreRegBankSelect();
-
-    if (PassConfig->addRegBankSelect())
-      return nullptr;
-
-    PassConfig->addPreGlobalInstructionSelect();
-
-    if (PassConfig->addGlobalInstructionSelect())
-      return nullptr;
-
-    // Pass to reset the MachineFunction if the ISel failed.
-    PM.add(createResetMachineFunctionPass(
-        PassConfig->reportDiagnosticWhenGlobalISelFallback(),
-        PassConfig->isGlobalISelAbortEnabled()));
-
-    // Provide a fallback path when we do not want to abort on
-    // not-yet-supported input.
-    if (!PassConfig->isGlobalISelAbortEnabled() &&
-        PassConfig->addInstSelector())
-      return nullptr;
-
-  } else if (PassConfig->addInstSelector())
+  if (PassConfig->addISelPasses())
     return nullptr;
-
   PassConfig->addMachinePasses();
-
   PassConfig->setInitialized();
 
   return &MMI->getContext();
 }
 
-bool LLVMTargetMachine::addPassesToEmitFile(
-    PassManagerBase &PM, raw_pwrite_stream &Out, CodeGenFileType FileType,
-    bool DisableVerify, AnalysisID StartBefore, AnalysisID StartAfter,
-    AnalysisID StopBefore, AnalysisID StopAfter,
-    MachineFunctionInitializer *MFInitializer) {
-  // Add common CodeGen passes.
-  MCContext *Context =
-      addPassesToGenerateCode(this, PM, DisableVerify, StartBefore, StartAfter,
-                              StopBefore, StopAfter, MFInitializer);
-  if (!Context)
-    return true;
-
-  if (StopBefore || StopAfter) {
-    PM.add(createPrintMIRPass(Out));
-    return false;
-  }
-
+bool LLVMTargetMachine::addAsmPrinter(PassManagerBase &PM,
+    raw_pwrite_stream &Out, CodeGenFileType FileType,
+    MCContext &Context) {
   if (Options.MCOptions.MCSaveTempLabels)
-    Context->setAllowTemporaryLabels(false);
+    Context.setAllowTemporaryLabels(false);
 
   const MCSubtargetInfo &STI = *getMCSubtargetInfo();
   const MCAsmInfo &MAI = *getMCAsmInfo();
@@ -226,14 +139,14 @@ bool LLVMTargetMachine::addPassesToEmitFile(
     // Create a code emitter if asked to show the encoding.
     MCCodeEmitter *MCE = nullptr;
     if (Options.MCOptions.ShowMCEncoding)
-      MCE = getTarget().createMCCodeEmitter(MII, MRI, *Context);
+      MCE = getTarget().createMCCodeEmitter(MII, MRI, Context);
 
     MCAsmBackend *MAB =
         getTarget().createMCAsmBackend(MRI, getTargetTriple().str(), TargetCPU,
                                        Options.MCOptions);
     auto FOut = llvm::make_unique<formatted_raw_ostream>(Out);
     MCStreamer *S = getTarget().createAsmStreamer(
-        *Context, std::move(FOut), Options.MCOptions.AsmVerbose,
+        Context, std::move(FOut), Options.MCOptions.AsmVerbose,
         Options.MCOptions.MCUseDwarfDirectory, InstPrinter, MCE, MAB,
         Options.MCOptions.ShowMCInst);
     AsmStreamer.reset(S);
@@ -242,7 +155,7 @@ bool LLVMTargetMachine::addPassesToEmitFile(
   case CGFT_ObjectFile: {
     // Create the code emitter for the target if it exists.  If not, .o file
     // emission fails.
-    MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(MII, MRI, *Context);
+    MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(MII, MRI, Context);
     MCAsmBackend *MAB =
         getTarget().createMCAsmBackend(MRI, getTargetTriple().str(), TargetCPU,
                                        Options.MCOptions);
@@ -250,11 +163,11 @@ bool LLVMTargetMachine::addPassesToEmitFile(
       return true;
 
     // Don't waste memory on names of temp labels.
-    Context->setUseNamesOnTempLabels(false);
+    Context.setUseNamesOnTempLabels(false);
 
     Triple T(getTargetTriple().str());
     AsmStreamer.reset(getTarget().createMCObjectStreamer(
-        T, *Context, *MAB, Out, MCE, STI, Options.MCOptions.MCRelaxAll,
+        T, Context, *MAB, Out, MCE, STI, Options.MCOptions.MCRelaxAll,
         Options.MCOptions.MCIncrementalLinkerCompatible,
         /*DWARFMustBeAtTheEnd*/ true));
     break;
@@ -262,7 +175,7 @@ bool LLVMTargetMachine::addPassesToEmitFile(
   case CGFT_Null:
     // The Null output is intended for use for performance analysis and testing,
     // not real users.
-    AsmStreamer.reset(getTarget().createNullStreamer(*Context));
+    AsmStreamer.reset(getTarget().createNullStreamer(Context));
     break;
   }
 
@@ -273,8 +186,29 @@ bool LLVMTargetMachine::addPassesToEmitFile(
     return true;
 
   PM.add(Printer);
-  PM.add(createFreeMachineFunctionPass());
+  return false;
+}
 
+bool LLVMTargetMachine::addPassesToEmitFile(
+    PassManagerBase &PM, raw_pwrite_stream &Out, CodeGenFileType FileType,
+    bool DisableVerify, AnalysisID StartBefore, AnalysisID StartAfter,
+    AnalysisID StopBefore, AnalysisID StopAfter,
+    MachineFunctionInitializer *MFInitializer) {
+  // Add common CodeGen passes.
+  MCContext *Context =
+      addPassesToGenerateCode(this, PM, DisableVerify, StartBefore, StartAfter,
+                              StopBefore, StopAfter, MFInitializer);
+  if (!Context)
+    return true;
+
+  if (StopBefore || StopAfter) {
+    PM.add(createPrintMIRPass(Out));
+  } else {
+    if (addAsmPrinter(PM, Out, FileType, *Context))
+      return true;
+  }
+
+  PM.add(createFreeMachineFunctionPass());
   return false;
 }
 
diff --git a/llvm/lib/CodeGen/TargetPassConfig.cpp b/llvm/lib/CodeGen/TargetPassConfig.cpp
index 72d5e99..b1918b1 100644
--- a/llvm/lib/CodeGen/TargetPassConfig.cpp
+++ b/llvm/lib/CodeGen/TargetPassConfig.cpp
@@ -20,6 +20,7 @@
 #include "llvm/Analysis/CallGraphSCCPass.h"
 #include "llvm/Analysis/Passes.h"
 #include "llvm/Analysis/ScopedNoAliasAA.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
 #include "llvm/Analysis/TypeBasedAliasAnalysis.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/RegAllocRegistry.h"
@@ -95,6 +96,16 @@ static cl::opt<bool> VerifyMachineCode("verify-machineinstrs", cl::Hidden,
 static cl::opt<bool> EnableMachineOutliner("enable-machine-outliner",
     cl::Hidden,
     cl::desc("Enable machine outliner"));
+// Enable or disable FastISel. Both options are needed, because
+// FastISel is enabled by default with -fast, and we wish to be
+// able to enable or disable fast-isel independently from -O0.
+static cl::opt<cl::boolOrDefault>
+EnableFastISelOption("fast-isel", cl::Hidden,
+  cl::desc("Enable the \"fast\" instruction selector"));
+
+static cl::opt<cl::boolOrDefault>
+    EnableGlobalISel("global-isel", cl::Hidden,
+                     cl::desc("Enable the \"global\" instruction selector"));
 
 static cl::opt<std::string>
 PrintMachineInstrs("print-machineinstrs", cl::ValueOptional,
@@ -571,6 +582,66 @@ void TargetPassConfig::addISelPrepare() {
     addPass(createVerifierPass());
 }
 
+bool TargetPassConfig::addCoreISelPasses() {
+  // Enable FastISel with -fast, but allow that to be overridden.
+  TM->setO0WantsFastISel(EnableFastISelOption != cl::BOU_FALSE);
+  if (EnableFastISelOption == cl::BOU_TRUE ||
+      (TM->getOptLevel() == CodeGenOpt::None && TM->getO0WantsFastISel()))
+    TM->setFastISel(true);
+
+  // Ask the target for an isel.
+  // Enable GlobalISel if the target wants to, but allow that to be overriden.
+  if (EnableGlobalISel == cl::BOU_TRUE ||
+      (EnableGlobalISel == cl::BOU_UNSET && isGlobalISelEnabled())) {
+    if (addIRTranslator())
+      return true;
+
+    addPreLegalizeMachineIR();
+
+    if (addLegalizeMachineIR())
+      return true;
+
+    // Before running the register bank selector, ask the target if it
+    // wants to run some passes.
+    addPreRegBankSelect();
+
+    if (addRegBankSelect())
+      return true;
+
+    addPreGlobalInstructionSelect();
+
+    if (addGlobalInstructionSelect())
+      return true;
+
+    // Pass to reset the MachineFunction if the ISel failed.
+    addPass(createResetMachineFunctionPass(
+        reportDiagnosticWhenGlobalISelFallback(), isGlobalISelAbortEnabled()));
+
+    // Provide a fallback path when we do not want to abort on
+    // not-yet-supported input.
+    if (!isGlobalISelAbortEnabled() && addInstSelector())
+      return true;
+
+  } else if (addInstSelector())
+    return true;
+
+  return false;
+}
+
+bool TargetPassConfig::addISelPasses() {
+  if (TM->Options.EmulatedTLS)
+    addPass(createLowerEmuTLSPass());
+
+  addPass(createPreISelIntrinsicLoweringPass());
+  addPass(createTargetTransformInfoWrapperPass(TM->getTargetIRAnalysis()));
+  addIRPasses();
+  addCodeGenPrepare();
+  addPassesToHandleExceptions();
+  addISelPrepare();
+
+  return addCoreISelPasses();
+}
+
 /// -regalloc=... command line option.
 static FunctionPass *useDefaultRegisterAllocator() { return nullptr; }
 static cl::opt<RegisterRegAlloc::FunctionPassCtor, false,
diff --git a/llvm/test/CodeGen/Generic/llc-start-stop.ll b/llvm/test/CodeGen/Generic/llc-start-stop.ll
index 7508f94..49407fb 100644
--- a/llvm/test/CodeGen/Generic/llc-start-stop.ll
+++ b/llvm/test/CodeGen/Generic/llc-start-stop.ll
@@ -10,12 +10,12 @@
 ; STOP-BEFORE-NOT: Loop Strength Reduction
 
 ; RUN: llc < %s -debug-pass=Structure -start-after=loop-reduce -o /dev/null 2>&1 | FileCheck %s -check-prefix=START-AFTER
-; START-AFTER: -machine-branch-prob -pre-isel-intrinsic-lowering
+; START-AFTER: -machine-branch-prob -gc-lowering
 ; START-AFTER: FunctionPass Manager
 ; START-AFTER-NEXT: Lower Garbage Collection Instructions
 
 ; RUN: llc < %s -debug-pass=Structure -start-before=loop-reduce -o /dev/null 2>&1 | FileCheck %s -check-prefix=START-BEFORE
-; START-BEFORE: -machine-branch-prob -pre-isel-intrinsic-lowering
+; START-BEFORE: -machine-branch-prob -domtree
 ; START-BEFORE: FunctionPass Manager
 ; START-BEFORE: Loop Strength Reduction
 ; START-BEFORE-NEXT: Lower Garbage Collection Instructions
diff --git a/llvm/test/CodeGen/X86/O0-pipeline.ll b/llvm/test/CodeGen/X86/O0-pipeline.ll
index 874e3e3..5e375cc 100644
--- a/llvm/test/CodeGen/X86/O0-pipeline.ll
+++ b/llvm/test/CodeGen/X86/O0-pipeline.ll
@@ -5,12 +5,12 @@
 ; CHECK-LABEL: Pass Arguments:
 ; CHECK-NEXT: Target Library Information
 ; CHECK-NEXT: Target Pass Configuration
+; CHECK-NEXT: Machine Module Information
 ; CHECK-NEXT: Target Transform Information
 ; CHECK-NEXT: Type-Based Alias Analysis
 ; CHECK-NEXT: Scoped NoAlias Alias Analysis
 ; CHECK-NEXT: Assumption Cache Tracker
 ; CHECK-NEXT: Create Garbage Collector Module Metadata
-; CHECK-NEXT: Machine Module Information
 ; CHECK-NEXT: Machine Branch Probability Analysis
 ; CHECK-NEXT:   ModulePass Manager
 ; CHECK-NEXT:     Pre-ISel Intrinsic Lowering