[llvm] r193811 - Add support for stack map generation in the X86 backend.
Aaron Ballman
aaron at aaronballman.com
Mon Nov 18 13:56:32 PST 2013
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.
~Aaron
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