From 84be3d5a73313eb19f2f9e0512153cd2e6f46c54 Mon Sep 17 00:00:00 2001 From: Jakob Stoklund Olesen Date: Sat, 5 Jan 2013 05:05:51 +0000 Subject: [PATCH] Don't call destructors on MachineInstr and MachineOperand. The series of patches leading up to this one makes llc -O0 run 8% faster. When deallocating a MachineFunction, there is no need to visit all MachineInstr and MachineOperand objects to deallocate them. All their memory come from a BumpPtrAllocator that is about to be purged, and they have empty destructors anyway. This only applies when deallocating the MachineFunction. DeleteMachineInstr() should still be used to recycle MI memory during the codegen passes. Remove the LeakDetector support for MachineInstr. I've never seen it used before, and now it definitely doesn't work. With this patch, leaked MachineInstrs would be much less of a problem since all of their memory will be reclaimed by ~MachineFunction(). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171599 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/CodeGen/MachineInstr.h | 8 ++++++-- lib/CodeGen/MachineFunction.cpp | 16 ++++++++++++---- lib/CodeGen/MachineInstr.cpp | 21 +-------------------- lib/CodeGen/MachineRegisterInfo.cpp | 6 ------ 4 files changed, 19 insertions(+), 32 deletions(-) diff --git a/include/llvm/CodeGen/MachineInstr.h b/include/llvm/CodeGen/MachineInstr.h index 3c7b213533f..76738e28c26 100644 --- a/include/llvm/CodeGen/MachineInstr.h +++ b/include/llvm/CodeGen/MachineInstr.h @@ -43,6 +43,10 @@ class MachineMemOperand; //===----------------------------------------------------------------------===// /// MachineInstr - Representation of each machine instruction. /// +/// This class isn't a POD type, but it must have a trivial destructor. When a +/// MachineFunction is deleted, all the contained MachineInstrs are deallocated +/// without having their destructor called. +/// class MachineInstr : public ilist_node { public: typedef MachineMemOperand **mmo_iterator; @@ -90,6 +94,8 @@ private: MachineInstr(const MachineInstr&) LLVM_DELETED_FUNCTION; void operator=(const MachineInstr&) LLVM_DELETED_FUNCTION; + // Use MachineFunction::DeleteMachineInstr() instead. + ~MachineInstr() LLVM_DELETED_FUNCTION; // Intrusive list support friend struct ilist_traits; @@ -106,8 +112,6 @@ private: MachineInstr(MachineFunction&, const MCInstrDesc &MCID, const DebugLoc dl, bool NoImp = false); - ~MachineInstr(); - // MachineInstrs are pool-allocated and owned by MachineFunction. friend class MachineFunction; diff --git a/lib/CodeGen/MachineFunction.cpp b/lib/CodeGen/MachineFunction.cpp index 08d116afead..9647e83e24c 100644 --- a/lib/CodeGen/MachineFunction.cpp +++ b/lib/CodeGen/MachineFunction.cpp @@ -76,7 +76,13 @@ MachineFunction::MachineFunction(const Function *F, const TargetMachine &TM, } MachineFunction::~MachineFunction() { - BasicBlocks.clear(); + // Don't call destructors on MachineInstr and MachineOperand. All of their + // memory comes from the BumpPtrAllocator which is about to be purged. + // + // Do call MachineBasicBlock destructors, it contains std::vectors. + for (iterator I = begin(), E = end(); I != E; I = BasicBlocks.erase(I)) + I->Insts.clearAndLeakNodesUnsafely(); + InstructionRecycler.clear(Allocator); OperandRecycler.clear(Allocator); BasicBlockRecycler.clear(Allocator); @@ -176,15 +182,17 @@ MachineFunction::CloneMachineInstr(const MachineInstr *Orig) { /// DeleteMachineInstr - Delete the given MachineInstr. /// +/// This function also serves as the MachineInstr destructor - the real +/// ~MachineInstr() destructor must be empty. void MachineFunction::DeleteMachineInstr(MachineInstr *MI) { // Strip it for parts. The operand array and the MI object itself are // independently recyclable. if (MI->Operands) deallocateOperandArray(MI->CapOperands, MI->Operands); - MI->Operands = 0; - MI->NumOperands = 0; - MI->~MachineInstr(); + // Don't call ~MachineInstr() which must be trivial anyway because + // ~MachineFunction drops whole lists of MachineInstrs wihout calling their + // destructors. InstructionRecycler.Deallocate(Allocator, MI); } diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp index d3342987c05..3255fa6e451 100644 --- a/lib/CodeGen/MachineInstr.cpp +++ b/lib/CodeGen/MachineInstr.cpp @@ -35,7 +35,6 @@ #include "llvm/MC/MCSymbol.h" #include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" -#include "llvm/Support/LeakDetector.h" #include "llvm/Support/MathExtras.h" #include "llvm/Support/raw_ostream.h" #include "llvm/Target/TargetInstrInfo.h" @@ -544,8 +543,6 @@ MachineInstr::MachineInstr(MachineFunction &MF, const MCInstrDesc &tid, if (!NoImp) addImplicitDefUseOperands(MF); - // Make sure that we get added to a machine basicblock - LeakDetector::addGarbageObject(this); } /// MachineInstr ctor - Copies MachineInstr arg exactly @@ -558,28 +555,12 @@ MachineInstr::MachineInstr(MachineFunction &MF, const MachineInstr &MI) CapOperands = OperandCapacity::get(MI.getNumOperands()); Operands = MF.allocateOperandArray(CapOperands); - // Add operands + // Copy operands. for (unsigned i = 0; i != MI.getNumOperands(); ++i) addOperand(MF, MI.getOperand(i)); // Copy all the sensible flags. setFlags(MI.Flags); - - // Set parent to null. - Parent = 0; - - LeakDetector::addGarbageObject(this); -} - -MachineInstr::~MachineInstr() { - LeakDetector::removeGarbageObject(this); -#ifndef NDEBUG - for (unsigned i = 0, e = getNumOperands(); i != e; ++i) { - assert(Operands[i].ParentMI == this && "ParentMI mismatch!"); - assert((!Operands[i].isReg() || !Operands[i].isOnRegUseList()) && - "Reg operand def/use list corrupted"); - } -#endif } /// getRegInfo - If this instruction is embedded into a MachineFunction, diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp index 9858b4999e0..21877e52c25 100644 --- a/lib/CodeGen/MachineRegisterInfo.cpp +++ b/lib/CodeGen/MachineRegisterInfo.cpp @@ -30,12 +30,6 @@ MachineRegisterInfo::MachineRegisterInfo(const TargetRegisterInfo &TRI) } MachineRegisterInfo::~MachineRegisterInfo() { -#ifndef NDEBUG - clearVirtRegs(); - for (unsigned i = 0, e = TRI->getNumRegs(); i != e; ++i) - assert(!PhysRegUseDefLists[i] && - "PhysRegUseDefLists has entries after all instructions are deleted"); -#endif delete [] PhysRegUseDefLists; }