llc: Add a 'run-pass' option.

This commit adds a 'run-pass' option to llc, which instructs the compiler to run
one specific code generation pass only.

Llc already has the 'start-after' and the 'stop-after' options, and this new
option complements the other two by making it easier to write tests that want
to invoke a single pass only.

Reviewers: Duncan P. N. Exon Smith

Differential Revision: http://reviews.llvm.org/D10776

llvm-svn: 241476

4 files changed, 20 insertions, 15 deletions

diff --git a/llvm/lib/CodeGen/LLVMTargetMachine.cpp b/llvm/lib/CodeGen/LLVMTargetMachine.cpp
index b486bdc9145..37299eb664c 100644
--- a/llvm/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/llvm/lib/CodeGen/LLVMTargetMachine.cpp
@@ -90,8 +90,8 @@ TargetIRAnalysis LLVMTargetMachine::getTargetIRAnalysis() {
 /// addPassesToX helper drives creation and initialization of TargetPassConfig.
 static MCContext *
 addPassesToGenerateCode(LLVMTargetMachine *TM, PassManagerBase &PM,
-                        bool DisableVerify, AnalysisID StartAfter,
-                        AnalysisID StopAfter,
+                        bool DisableVerify, AnalysisID StartBefore,
+                        AnalysisID StartAfter, AnalysisID StopAfter,
                         MachineFunctionInitializer *MFInitializer = nullptr) {
 
   // Add internal analysis passes from the target machine.
@@ -100,7 +100,7 @@ addPassesToGenerateCode(LLVMTargetMachine *TM, PassManagerBase &PM,
   // Targets may override createPassConfig to provide a target-specific
   // subclass.
   TargetPassConfig *PassConfig = TM->createPassConfig(PM);
-  PassConfig->setStartStopPasses(StartAfter, StopAfter);
+  PassConfig->setStartStopPasses(StartBefore, StartAfter, StopAfter);
 
   // Set PassConfig options provided by TargetMachine.
   PassConfig->setDisableVerify(DisableVerify);
@@ -143,11 +143,12 @@ addPassesToGenerateCode(LLVMTargetMachine *TM, PassManagerBase &PM,
 
 bool LLVMTargetMachine::addPassesToEmitFile(
     PassManagerBase &PM, raw_pwrite_stream &Out, CodeGenFileType FileType,
-    bool DisableVerify, AnalysisID StartAfter, AnalysisID StopAfter,
-    MachineFunctionInitializer *MFInitializer) {
+    bool DisableVerify, AnalysisID StartBefore, AnalysisID StartAfter,
+    AnalysisID StopAfter, MachineFunctionInitializer *MFInitializer) {
   // Add common CodeGen passes.
-  MCContext *Context = addPassesToGenerateCode(
-      this, PM, DisableVerify, StartAfter, StopAfter, MFInitializer);
+  MCContext *Context =
+      addPassesToGenerateCode(this, PM, DisableVerify, StartBefore, StartAfter,
+                              StopAfter, MFInitializer);
   if (!Context)
     return true;
 
@@ -231,7 +232,8 @@ bool LLVMTargetMachine::addPassesToEmitMC(PassManagerBase &PM, MCContext *&Ctx,
                                           raw_pwrite_stream &Out,
                                           bool DisableVerify) {
   // Add common CodeGen passes.
-  Ctx = addPassesToGenerateCode(this, PM, DisableVerify, nullptr, nullptr);
+  Ctx = addPassesToGenerateCode(this, PM, DisableVerify, nullptr, nullptr,
+                                nullptr);
   if (!Ctx)
     return true;
 
diff --git a/llvm/lib/CodeGen/Passes.cpp b/llvm/lib/CodeGen/Passes.cpp
index 210a7a1649c..0821e6ad158 100644
--- a/llvm/lib/CodeGen/Passes.cpp
+++ b/llvm/lib/CodeGen/Passes.cpp
@@ -214,10 +214,10 @@ TargetPassConfig::~TargetPassConfig() {
 // Out of line constructor provides default values for pass options and
 // registers all common codegen passes.
 TargetPassConfig::TargetPassConfig(TargetMachine *tm, PassManagerBase &pm)
-    : ImmutablePass(ID), PM(&pm), StartAfter(nullptr), StopAfter(nullptr),
-      Started(true), Stopped(false), AddingMachinePasses(false), TM(tm),
-      Impl(nullptr), Initialized(false), DisableVerify(false),
-      EnableTailMerge(true), EnableShrinkWrap(false) {
+    : ImmutablePass(ID), PM(&pm), StartBefore(nullptr), StartAfter(nullptr),
+      StopAfter(nullptr), Started(true), Stopped(false),
+      AddingMachinePasses(false), TM(tm), Impl(nullptr), Initialized(false),
+      DisableVerify(false), EnableTailMerge(true), EnableShrinkWrap(false) {
 
   Impl = new PassConfigImpl();
 
@@ -288,6 +288,8 @@ void TargetPassConfig::addPass(Pass *P, bool verifyAfter, bool printAfter) {
   // and shouldn't reference it.
   AnalysisID PassID = P->getPassID();
 
+  if (StartBefore == PassID)
+    Started = true;
   if (Started && !Stopped) {
     std::string Banner;
     // Construct banner message before PM->add() as that may delete the pass.
diff --git a/llvm/lib/Target/CppBackend/CPPBackend.cpp b/llvm/lib/Target/CppBackend/CPPBackend.cpp
index bc5d7f65b2f..272688edb8a 100644
--- a/llvm/lib/Target/CppBackend/CPPBackend.cpp
+++ b/llvm/lib/Target/CppBackend/CPPBackend.cpp
@@ -2148,8 +2148,8 @@ char CppWriter::ID = 0;
 
 bool CPPTargetMachine::addPassesToEmitFile(
     PassManagerBase &PM, raw_pwrite_stream &o, CodeGenFileType FileType,
-    bool DisableVerify, AnalysisID StartAfter, AnalysisID StopAfter,
-    MachineFunctionInitializer *MFInitializer) {
+    bool DisableVerify, AnalysisID StartBefore, AnalysisID StartAfter,
+    AnalysisID StopAfter, MachineFunctionInitializer *MFInitializer) {
   if (FileType != TargetMachine::CGFT_AssemblyFile)
     return true;
   auto FOut = llvm::make_unique<formatted_raw_ostream>(o);
diff --git a/llvm/lib/Target/CppBackend/CPPTargetMachine.h b/llvm/lib/Target/CppBackend/CPPTargetMachine.h
index ebf0635b12e..00e402feffb 100644
--- a/llvm/lib/Target/CppBackend/CPPTargetMachine.h
+++ b/llvm/lib/Target/CppBackend/CPPTargetMachine.h
@@ -31,7 +31,8 @@ struct CPPTargetMachine : public TargetMachine {
 public:
   bool addPassesToEmitFile(PassManagerBase &PM, raw_pwrite_stream &Out,
                            CodeGenFileType FileType, bool DisableVerify,
-                           AnalysisID StartAfter, AnalysisID StopAfter,
+                           AnalysisID StartBefore, AnalysisID StartAfter,
+                           AnalysisID StopAfter,
                            MachineFunctionInitializer *MFInitializer) override;
 };