[llvm] r193811 - Add support for stack map generation in the X86 backend.
Andrew Trick
atrick at apple.com
Tue Nov 19 10:34:10 PST 2013
On Nov 18, 2013, at 1:56 PM, Aaron Ballman <aaron at aaronballman.com> wrote:
> On Thu, Oct 31, 2013 at 6:11 PM, Andrew Trick <atrick at apple.com> wrote:
>> Author: atrick
>> Date: Thu Oct 31 17:11:56 2013
>> New Revision: 193811
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=193811&view=rev
>> Log:
>> Add support for stack map generation in the X86 backend.
>>
>> Originally implemented by Lang Hames.
>>
>> Added:
>> llvm/trunk/include/llvm/CodeGen/StackMaps.h
>> llvm/trunk/lib/CodeGen/StackMaps.cpp
>> llvm/trunk/test/CodeGen/X86/patchpoint.ll
>> llvm/trunk/test/CodeGen/X86/stackmap.ll
>> Modified:
>> llvm/trunk/lib/CodeGen/CMakeLists.txt
>> llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
>> llvm/trunk/lib/Target/X86/X86AsmPrinter.cpp
>> llvm/trunk/lib/Target/X86/X86AsmPrinter.h
>> llvm/trunk/lib/Target/X86/X86InstrInfo.cpp
>> llvm/trunk/lib/Target/X86/X86MCInstLower.cpp
>>
>> Added: llvm/trunk/include/llvm/CodeGen/StackMaps.h
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/StackMaps.h?rev=193811&view=auto
>> ==============================================================================
>> --- llvm/trunk/include/llvm/CodeGen/StackMaps.h (added)
>> +++ llvm/trunk/include/llvm/CodeGen/StackMaps.h Thu Oct 31 17:11:56 2013
>> @@ -0,0 +1,107 @@
>> +//===------------------- StackMaps.h - StackMaps ----------------*- C++ -*-===//
>> +//
>> +// The LLVM Compiler Infrastructure
>> +//
>> +// This file is distributed under the University of Illinois Open Source
>> +// License. See LICENSE.TXT for details.
>> +//
>> +//===----------------------------------------------------------------------===//
>> +
>> +#ifndef LLVM_STACKMAPS
>> +#define LLVM_STACKMAPS
>> +
>> +#include "llvm/ADT/SmallVector.h"
>> +#include "llvm/CodeGen/MachineInstr.h"
>> +#include <map>
>> +#include <vector>
>> +
>> +namespace llvm {
>> +
>> +class AsmPrinter;
>> +class MCExpr;
>> +
>> +class StackMaps {
>> +public:
>> + struct Location {
>> + enum LocationType { Unprocessed, Register, Direct, Indirect, Constant,
>> + ConstantIndex };
>> + LocationType LocType;
>> + unsigned Reg;
>> + int64_t Offset;
>> + Location() : LocType(Unprocessed), Reg(0), Offset(0) {}
>> + Location(LocationType LocType, unsigned Reg, int64_t Offset)
>> + : LocType(LocType), Reg(Reg), Offset(Offset) {}
>> + };
>> +
>> + // Typedef a function pointer for functions that parse sequences of operands
>> + // and return a Location, plus a new "next" operand iterator.
>> + typedef std::pair<Location, MachineInstr::const_mop_iterator>
>> + (*OperandParser)(MachineInstr::const_mop_iterator,
>> + MachineInstr::const_mop_iterator);
>> +
>> + // OpTypes are used to encode information about the following logical
>> + // operand (which may consist of several MachineOperands) for the
>> + // OpParser.
>> + typedef enum { DirectMemRefOp, IndirectMemRefOp, ConstantOp } OpType;
>> +
>> + StackMaps(AsmPrinter &AP, OperandParser OpParser)
>> + : AP(AP), OpParser(OpParser) {}
>> +
>> + /// This should be called by the MC lowering code _immediately_ before
>> + /// lowering the MI to an MCInst. It records where the operands for the
>> + /// instruction are stored, and outputs a label to record the offset of
>> + /// the call from the start of the text section.
>> + void recordStackMap(const MachineInstr &MI, uint32_t ID,
>> + MachineInstr::const_mop_iterator MOI,
>> + MachineInstr::const_mop_iterator MOE);
>> +
>> + /// If there is any stack map data, create a stack map section and serialize
>> + /// the map info into it. This clears the stack map data structures
>> + /// afterwards.
>> + void serializeToStackMapSection();
>> +
>> +private:
>> +
>> + typedef SmallVector<Location, 8> LocationVec;
>> +
>> + struct CallsiteInfo {
>> + const MCExpr *CSOffsetExpr;
>> + unsigned ID;
>> + LocationVec Locations;
>> + CallsiteInfo() : CSOffsetExpr(0), ID(0) {}
>> + CallsiteInfo(const MCExpr *CSOffsetExpr, unsigned ID,
>> + LocationVec Locations)
>> + : CSOffsetExpr(CSOffsetExpr), ID(ID), Locations(Locations) {}
>> + };
>> +
>> + typedef std::vector<CallsiteInfo> CallsiteInfoList;
>> +
>> + struct ConstantPool {
>> + private:
>> + typedef std::map<int64_t, size_t> ConstantsMap;
>> + std::vector<int64_t> ConstantsList;
>> + ConstantsMap ConstantIndexes;
>> +
>> + public:
>> + size_t getNumConstants() const { return ConstantsList.size(); }
>> + int64_t getConstant(size_t Idx) const { return ConstantsList[Idx]; }
>> + size_t getConstantIndex(int64_t ConstVal) {
>> + size_t NextIdx = ConstantsList.size();
>> + ConstantsMap::const_iterator I =
>> + ConstantIndexes.insert(ConstantIndexes.end(),
>> + std::make_pair(ConstVal, NextIdx));
>> + if (I->second == NextIdx)
>> + ConstantsList.push_back(ConstVal);
>> + return I->second;
>> + }
>> + };
>> +
>> + AsmPrinter &AP;
>> + OperandParser OpParser;
>> + CallsiteInfoList CSInfos;
>> + ConstantPool ConstPool;
>> +};
>> +
>> +}
>> +
>> +#endif // LLVM_STACKMAPS
>>
>> Modified: llvm/trunk/lib/CodeGen/CMakeLists.txt
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/CMakeLists.txt?rev=193811&r1=193810&r2=193811&view=diff
>> ==============================================================================
>> --- llvm/trunk/lib/CodeGen/CMakeLists.txt (original)
>> +++ llvm/trunk/lib/CodeGen/CMakeLists.txt Thu Oct 31 17:11:56 2013
>> @@ -97,6 +97,7 @@ add_llvm_library(LLVMCodeGen
>> StackColoring.cpp
>> StackProtector.cpp
>> StackSlotColoring.cpp
>> + StackMaps.cpp
>> TailDuplication.cpp
>> TargetFrameLoweringImpl.cpp
>> TargetInstrInfo.cpp
>>
>> Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp?rev=193811&r1=193810&r2=193811&view=diff
>> ==============================================================================
>> --- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (original)
>> +++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp Thu Oct 31 17:11:56 2013
>> @@ -33,6 +33,7 @@
>> #include "llvm/CodeGen/MachineModuleInfo.h"
>> #include "llvm/CodeGen/MachineRegisterInfo.h"
>> #include "llvm/CodeGen/SelectionDAG.h"
>> +#include "llvm/CodeGen/StackMaps.h"
>> #include "llvm/DebugInfo.h"
>> #include "llvm/IR/CallingConv.h"
>> #include "llvm/IR/Constants.h"
>> @@ -6879,6 +6880,8 @@ void SelectionDAGBuilder::visitPatchpoin
>> SDValue OpVal = getValue(CI.getArgOperand(i));
>> if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(OpVal)) {
>> Ops.push_back(
>> + DAG.getTargetConstant(StackMaps::ConstantOp, MVT::i64));
>> + Ops.push_back(
>> DAG.getTargetConstant(C->getSExtValue(), MVT::i64));
>> } else
>> Ops.push_back(OpVal);
>>
>> Added: llvm/trunk/lib/CodeGen/StackMaps.cpp
>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/StackMaps.cpp?rev=193811&view=auto
>> ==============================================================================
>> --- llvm/trunk/lib/CodeGen/StackMaps.cpp (added)
>> +++ llvm/trunk/lib/CodeGen/StackMaps.cpp Thu Oct 31 17:11:56 2013
>> @@ -0,0 +1,213 @@
>> +//===---------------------------- StackMaps.cpp ---------------------------===//
>> +//
>> +// The LLVM Compiler Infrastructure
>> +//
>> +// This file is distributed under the University of Illinois Open Source
>> +// License. See LICENSE.TXT for details.
>> +//
>> +//===----------------------------------------------------------------------===//
>> +
>> +#define DEBUG_TYPE "stackmaps"
>> +
>> +#include "llvm/CodeGen/StackMaps.h"
>> +
>> +#include "llvm/CodeGen/AsmPrinter.h"
>> +#include "llvm/CodeGen/MachineInstr.h"
>> +#include "llvm/MC/MCContext.h"
>> +#include "llvm/MC/MCExpr.h"
>> +#include "llvm/MC/MCSectionMachO.h"
>> +#include "llvm/MC/MCStreamer.h"
>> +#include "llvm/Support/Debug.h"
>> +#include "llvm/Support/raw_ostream.h"
>> +#include "llvm/Target/TargetOpcodes.h"
>> +#include "llvm/Target/TargetMachine.h"
>> +#include "llvm/Target/TargetRegisterInfo.h"
>> +
>> +#include <iterator>
>> +
>> +using namespace llvm;
>> +
>> +void StackMaps::recordStackMap(const MachineInstr &MI, uint32_t ID,
>> + MachineInstr::const_mop_iterator MOI,
>> + MachineInstr::const_mop_iterator MOE) {
>> +
>> + MCContext &OutContext = AP.OutStreamer.getContext();
>> + MCSymbol *MILabel = OutContext.CreateTempSymbol();
>> + AP.OutStreamer.EmitLabel(MILabel);
>> +
>> + LocationVec CallsiteLocs;
>> +
>> + while (MOI != MOE) {
>> + std::pair<Location, MachineInstr::const_mop_iterator> ParseResult =
>> + OpParser(MOI, MOE);
>> +
>> + Location &Loc = ParseResult.first;
>> +
>> + // Move large constants into the constant pool.
>> + if (Loc.LocType == Location::Constant && (Loc.Offset & ~0xFFFFFFFFULL)) {
>> + Loc.LocType = Location::ConstantIndex;
>> + Loc.Offset = ConstPool.getConstantIndex(Loc.Offset);
>> + }
>> +
>> + CallsiteLocs.push_back(Loc);
>> + MOI = ParseResult.second;
>> + }
>> +
>> + const MCExpr *CSOffsetExpr = MCBinaryExpr::CreateSub(
>> + MCSymbolRefExpr::Create(MILabel, OutContext),
>> + MCSymbolRefExpr::Create(AP.CurrentFnSym, OutContext),
>> + OutContext);
>> +
>> + CSInfos.push_back(CallsiteInfo(CSOffsetExpr, ID, CallsiteLocs));
>> +}
>> +
>> +/// serializeToStackMapSection conceptually populates the following fields:
>> +///
>> +/// uint32 : Reserved (header)
>> +/// uint32 : NumConstants
>> +/// int64 : Constants[NumConstants]
>> +/// uint32 : NumRecords
>> +/// StkMapRecord[NumRecords] {
>> +/// uint32 : PatchPoint ID
>> +/// uint32 : Instruction Offset
>> +/// uint16 : Reserved (record flags)
>> +/// uint16 : NumLocations
>> +/// Location[NumLocations] {
>> +/// uint8 : Register | Direct | Indirect | Constant | ConstantIndex
>> +/// uint8 : Reserved (location flags)
>> +/// uint16 : Dwarf RegNum
>> +/// int32 : Offset
>> +/// }
>> +/// }
>> +///
>> +/// Location Encoding, Type, Value:
>> +/// 0x1, Register, Reg (value in register)
>> +/// 0x2, Direct, Reg + Offset (frame index)
>> +/// 0x3, Indirect, [Reg + Offset] (spilled value)
>> +/// 0x4, Constant, Offset (small constant)
>> +/// 0x5, ConstIndex, Constants[Offset] (large constant)
>> +///
>> +void StackMaps::serializeToStackMapSection() {
>> + // Bail out if there's no stack map data.
>> + if (CSInfos.empty())
>> + return;
>> +
>> + MCContext &OutContext = AP.OutStreamer.getContext();
>> + const TargetRegisterInfo *TRI = AP.TM.getRegisterInfo();
>> +
>> + // Create the section.
>> + const MCSection *StackMapSection =
>> + OutContext.getMachOSection("__LLVM_STACKMAPS", "__llvm_stackmaps", 0,
>> + SectionKind::getMetadata());
>> + AP.OutStreamer.SwitchSection(StackMapSection);
>> +
>> + // Emit a dummy symbol to force section inclusion.
>> + AP.OutStreamer.EmitLabel(
>> + OutContext.GetOrCreateSymbol(Twine("__LLVM_StackMaps")));
>> +
>> + // Serialize data.
>> + const char *WSMP = "Stack Maps: ";
>> + const MCRegisterInfo &MCRI = *OutContext.getRegisterInfo();
>> +
>> + DEBUG(dbgs() << "********** Stack Map Output **********\n");
>> +
>> + // Header.
>> + AP.OutStreamer.EmitIntValue(0, 4);
>> +
>> + // Num constants.
>> + AP.OutStreamer.EmitIntValue(ConstPool.getNumConstants(), 4);
>> +
>> + // Constant pool entries.
>> + for (unsigned i = 0; i < ConstPool.getNumConstants(); ++i)
>> + AP.OutStreamer.EmitIntValue(ConstPool.getConstant(i), 8);
>> +
>> + DEBUG(dbgs() << WSMP << "#callsites = " << CSInfos.size() << "\n");
>> + AP.OutStreamer.EmitIntValue(CSInfos.size(), 4);
>> +
>> + for (CallsiteInfoList::const_iterator CSII = CSInfos.begin(),
>> + CSIE = CSInfos.end();
>> + CSII != CSIE; ++CSII) {
>> +
>> + unsigned CallsiteID = CSII->ID;
>> + const LocationVec &CSLocs = CSII->Locations;
>> +
>> + DEBUG(dbgs() << WSMP << "callsite " << CallsiteID << "\n");
>> +
>> + // Verify stack map entry. It's better to communicate a problem to the
>> + // runtime than crash in case of in-process compilation. Currently, we do
>> + // simple overflow checks, but we may eventually communicate other
>> + // compilation errors this way.
>> + if (CSLocs.size() > UINT16_MAX) {
>> + AP.OutStreamer.EmitIntValue(UINT32_MAX, 4); // Invalid ID.
>> + AP.OutStreamer.EmitValue(CSII->CSOffsetExpr, 4);
>> + AP.OutStreamer.EmitIntValue(0, 2); // Reserved.
>> + AP.OutStreamer.EmitIntValue(0, 2); // 0 locations.
>> + continue;
>> + }
>> +
>> + AP.OutStreamer.EmitIntValue(CallsiteID, 4);
>> + AP.OutStreamer.EmitValue(CSII->CSOffsetExpr, 4);
>> +
>> + // Reserved for flags.
>> + AP.OutStreamer.EmitIntValue(0, 2);
>> +
>> + DEBUG(dbgs() << WSMP << " has " << CSLocs.size() << " locations\n");
>> +
>> + AP.OutStreamer.EmitIntValue(CSLocs.size(), 2);
>> +
>> + unsigned operIdx = 0;
>> + for (LocationVec::const_iterator LocI = CSLocs.begin(), LocE = CSLocs.end();
>> + LocI != LocE; ++LocI, ++operIdx) {
>> + const Location &Loc = *LocI;
>> + DEBUG(
>> + dbgs() << WSMP << " Loc " << operIdx << ": ";
>> + switch (Loc.LocType) {
>> + case Location::Unprocessed:
>> + dbgs() << "<Unprocessed operand>";
>> + break;
>> + case Location::Register:
>> + dbgs() << "Register " << MCRI.getName(Loc.Reg);
>> + break;
>> + case Location::Direct:
>> + dbgs() << "Direct " << MCRI.getName(Loc.Reg);
>> + if (Loc.Offset)
>> + dbgs() << " + " << Loc.Offset;
>> + break;
>> + case Location::Indirect:
>> + dbgs() << "Indirect " << MCRI.getName(Loc.Reg)
>> + << " + " << Loc.Offset;
>> + break;
>> + case Location::Constant:
>> + dbgs() << "Constant " << Loc.Offset;
>> + break;
>> + case Location::ConstantIndex:
>> + dbgs() << "Constant Index " << Loc.Offset;
>> + break;
>> + }
>> + dbgs() << "\n";
>> + );
>> +
>> + unsigned RegNo = 0;
>> + if(Loc.Reg) {
>> + RegNo = MCRI.getDwarfRegNum(Loc.Reg, false);
>> + for (MCSuperRegIterator SR(Loc.Reg, TRI);
>> + SR.isValid() && (int)RegNo < 0; ++SR) {
>> + RegNo = TRI->getDwarfRegNum(*SR, false);
>> + }
>> + }
>> + else {
>> + assert((Loc.LocType != Location::Register
>> + && Loc.LocType != Location::Register) &&
>> + "Missing location register");
>
> This appears to be a typo -- LocType != Location::Register appears
> twice in the assert.
>
Thanks for taking time to review. r195138.
-Andy
> ~Aaron
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