CodeGen: Remove MachineFunctionAnalysis => Enable (Machine)ModulePasses

Re-apply this commit with the deletion of a MachineFunction delegated to
a separate pass to avoid use after free when doing this directly in
AsmPrinter.

This patch removes the MachineFunctionAnalysis. Instead we keep a
map from IR Function to MachineFunction in the MachineModuleInfo.

This allows the insertion of ModulePasses into the codegen pipeline
without breaking it because the MachineFunctionAnalysis gets dropped
before a module pass.

Peak memory should stay unchanged without a ModulePass in the codegen
pipeline: Previously the MachineFunction was freed at the end of a codegen
function pipeline because the MachineFunctionAnalysis was dropped; With
this patch the MachineFunction is freed after the AsmPrinter has
finished.

Differential Revision: http://reviews.llvm.org/D23736

llvm-svn: 279564

1 files changed, 7 insertions, 11 deletions

diff --git a/llvm/lib/CodeGen/LLVMTargetMachine.cpp b/llvm/lib/CodeGen/LLVMTargetMachine.cpp
index 9ed61c6685b..27acb306a65 100644
--- a/llvm/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/llvm/lib/CodeGen/LLVMTargetMachine.cpp
@@ -15,7 +15,6 @@
 #include "llvm/Analysis/Passes.h"
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/CodeGen/BasicTTIImpl.h"
-#include "llvm/CodeGen/MachineFunctionAnalysis.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/CodeGen/TargetPassConfig.h"
@@ -103,19 +102,15 @@ TargetIRAnalysis LLVMTargetMachine::getTargetIRAnalysis() {
 }
 
 MachineModuleInfo &
-LLVMTargetMachine::addMachineModuleInfo(PassManagerBase &PM) const {
-  MachineModuleInfo *MMI = new MachineModuleInfo(*getMCAsmInfo(),
+LLVMTargetMachine::addMachineModuleInfo(PassManagerBase &PM,
+                                        MachineFunctionInitializer *MFI) const {
+  MachineModuleInfo *MMI = new MachineModuleInfo(*this, *getMCAsmInfo(),
                                                  *getMCRegisterInfo(),
-                                                 getObjFileLowering());
+                                                 getObjFileLowering(), MFI);
   PM.add(MMI);
   return *MMI;
 }
 
-void LLVMTargetMachine::addMachineFunctionAnalysis(PassManagerBase &PM,
-    MachineFunctionInitializer *MFInitializer) const {
-  PM.add(new MachineFunctionAnalysis(*this, MFInitializer));
-}
-
 /// addPassesToX helper drives creation and initialization of TargetPassConfig.
 static MCContext *
 addPassesToGenerateCode(LLVMTargetMachine *TM, PassManagerBase &PM,
@@ -150,8 +145,7 @@ addPassesToGenerateCode(LLVMTargetMachine *TM, PassManagerBase &PM,
 
   PassConfig->addISelPrepare();
 
-  MachineModuleInfo &MMI = TM->addMachineModuleInfo(PM);
-  TM->addMachineFunctionAnalysis(PM, MFInitializer);
+  MachineModuleInfo &MMI = TM->addMachineModuleInfo(PM, MFInitializer);
 
   // Enable FastISel with -fast, but allow that to be overridden.
   TM->setO0WantsFastISel(EnableFastISelOption != cl::BOU_FALSE);
@@ -273,6 +267,7 @@ bool LLVMTargetMachine::addPassesToEmitFile(
     return true;
 
   PM.add(Printer);
+  PM.add(createFreeMachineFunctionPass());
 
   return false;
 }
@@ -319,6 +314,7 @@ bool LLVMTargetMachine::addPassesToEmitMC(PassManagerBase &PM, MCContext *&Ctx,
     return true;
 
   PM.add(Printer);
+  PM.add(createFreeMachineFunctionPass());
 
   return false; // success!
 }