Add a GC plugin for Erlang

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177867 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Yiannis Tsiouris 2013-03-25 13:47:46 +00:00
parent 2269c56a3c
commit 477de3a785
6 changed files with 234 additions and 0 deletions

View File

@ -26,6 +26,12 @@ namespace llvm {
/// Creates an ocaml-compatible metadata printer.
void linkOcamlGCPrinter();
/// Creates an erlang-compatible garbage collector.
void linkErlangGC();
/// Creates an erlang-compatible metadata printer.
void linkErlangGCPrinter();
/// Creates a shadow stack garbage collector. This collector requires no code
/// generator support.

View File

@ -29,6 +29,7 @@ namespace {
return;
llvm::linkOcamlGCPrinter();
llvm::linkErlangGCPrinter();
}
} ForceAsmWriterLinking; // Force link by creating a global definition.

View File

@ -37,6 +37,7 @@ namespace {
(void) llvm::createDefaultPBQPRegisterAllocator();
llvm::linkOcamlGC();
llvm::linkErlangGC();
llvm::linkShadowStackGC();
(void) llvm::createBURRListDAGScheduler(NULL, llvm::CodeGenOpt::Default);

View File

@ -0,0 +1,120 @@
//===-- ErlangGCPrinter.cpp - Erlang/OTP frametable emitter -----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the compiler plugin that is used in order to emit
// garbage collection information in a convenient layout for parsing and
// loading in the Erlang/OTP runtime.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/GCs.h"
#include "llvm/CodeGen/GCMetadataPrinter.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Metadata.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
#include "llvm/Target/TargetMachine.h"
using namespace llvm;
namespace {
class ErlangGCPrinter : public GCMetadataPrinter {
public:
void beginAssembly(AsmPrinter &AP);
void finishAssembly(AsmPrinter &AP);
};
}
static GCMetadataPrinterRegistry::Add<ErlangGCPrinter>
X("erlang", "erlang-compatible garbage collector");
void llvm::linkErlangGCPrinter() { }
void ErlangGCPrinter::beginAssembly(AsmPrinter &AP) { }
void ErlangGCPrinter::finishAssembly(AsmPrinter &AP) {
MCStreamer &OS = AP.OutStreamer;
unsigned IntPtrSize = AP.TM.getDataLayout()->getPointerSize();
// Put this in a custom .note section.
AP.OutStreamer.SwitchSection(AP.getObjFileLowering().getContext()
.getELFSection(".note.gc", ELF::SHT_PROGBITS, 0,
SectionKind::getDataRel()));
// For each function...
for (iterator FI = begin(), FE = end(); FI != FE; ++FI) {
GCFunctionInfo &MD = **FI;
/** A compact GC layout. Emit this data structure:
*
* struct {
* int16_t PointCount;
* void *SafePointAddress[PointCount];
* int16_t StackFrameSize; (in words)
* int16_t StackArity;
* int16_t LiveCount;
* int16_t LiveOffsets[LiveCount];
* } __gcmap_<FUNCTIONNAME>;
**/
// Align to address width.
AP.EmitAlignment(IntPtrSize == 4 ? 2 : 3);
// Emit PointCount.
OS.AddComment("safe point count");
AP.EmitInt16(MD.size());
// And each safe point...
for (GCFunctionInfo::iterator PI = MD.begin(), PE = MD.end(); PI != PE;
++PI) {
// Emit the address of the safe point.
OS.AddComment("safe point address");
MCSymbol *Label = PI->Label;
AP.EmitLabelPlusOffset(Label/*Hi*/, 0/*Offset*/, 4/*Size*/);
}
// Stack information never change in safe points! Only print info from the
// first call-site.
GCFunctionInfo::iterator PI = MD.begin();
// Emit the stack frame size.
OS.AddComment("stack frame size (in words)");
AP.EmitInt16(MD.getFrameSize() / IntPtrSize);
// Emit stack arity, i.e. the number of stacked arguments.
unsigned RegisteredArgs = IntPtrSize == 4 ? 5 : 6;
unsigned StackArity = MD.getFunction().arg_size() > RegisteredArgs ?
MD.getFunction().arg_size() - RegisteredArgs : 0;
OS.AddComment("stack arity");
AP.EmitInt16(StackArity);
// Emit the number of live roots in the function.
OS.AddComment("live root count");
AP.EmitInt16(MD.live_size(PI));
// And for each live root...
for (GCFunctionInfo::live_iterator LI = MD.live_begin(PI),
LE = MD.live_end(PI);
LI != LE; ++LI) {
// Emit live root's offset within the stack frame.
OS.AddComment("stack index (offset / wordsize)");
AP.EmitInt16(LI->StackOffset / IntPtrSize);
}
}
}

81
lib/CodeGen/ErlangGC.cpp Normal file
View File

@ -0,0 +1,81 @@
//===-- ErlangGC.cpp - Erlang/OTP GC strategy -------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Erlang/OTP runtime-compatible garbage collector
// (e.g. defines safe points, root initialization etc.)
//
// The frametable emitter is in ErlangGCPrinter.cpp.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/GCs.h"
#include "llvm/CodeGen/GCStrategy.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
using namespace llvm;
namespace {
class ErlangGC : public GCStrategy {
MCSymbol *InsertLabel(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
DebugLoc DL) const;
public:
ErlangGC();
bool findCustomSafePoints(GCFunctionInfo &FI, MachineFunction &MF);
};
}
static GCRegistry::Add<ErlangGC>
X("erlang", "erlang-compatible garbage collector");
void llvm::linkErlangGC() { }
ErlangGC::ErlangGC() {
InitRoots = false;
NeededSafePoints = 1 << GC::PostCall;
UsesMetadata = true;
CustomRoots = false;
CustomSafePoints = true;
}
MCSymbol *ErlangGC::InsertLabel(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
DebugLoc DL) const {
const TargetInstrInfo* TII = MBB.getParent()->getTarget().getInstrInfo();
MCSymbol *Label = MBB.getParent()->getContext().CreateTempSymbol();
BuildMI(MBB, MI, DL, TII->get(TargetOpcode::GC_LABEL)).addSym(Label);
return Label;
}
bool ErlangGC::findCustomSafePoints(GCFunctionInfo &FI, MachineFunction &MF) {
for (MachineFunction::iterator BBI = MF.begin(), BBE = MF.end(); BBI != BBE;
++BBI)
for (MachineBasicBlock::iterator MI = BBI->begin(), ME = BBI->end();
MI != ME; ++MI)
if (MI->getDesc().isCall()) {
// Do not treat tail call sites as safe points.
if (MI->getDesc().isTerminator())
continue;
/* Code copied from VisitCallPoint(...) */
MachineBasicBlock::iterator RAI = MI; ++RAI;
MCSymbol* Label = InsertLabel(*MI->getParent(), RAI, MI->getDebugLoc());
FI.addSafePoint(GC::PostCall, Label, MI->getDebugLoc());
}
return false;
}

View File

@ -0,0 +1,25 @@
; RUN: llc -mtriple=x86_64-linux-gnu < %s | FileCheck %s --check-prefix=CHECK64
; RUN: llc -mtriple=i686-linux-gnu < %s | FileCheck %s --check-prefix=CHECK32
define i32 @main(i32 %x) nounwind gc "erlang" {
%puts = tail call i32 @foo(i32 %x)
ret i32 0
; CHECK64: .section .note.gc,"",@progbits
; CHECK64-NEXT: .align 8
; CHECK64-NEXT: .short 1 # safe point count
; CHECK64-NEXT: .long .Ltmp0 # safe point address
; CHECK64-NEXT: .short 1 # stack frame size (in words)
; CHECK64-NEXT: .short 0 # stack arity
; CHECK64-NEXT: .short 0 # live root count
; CHECK32: .section .note.gc,"",@progbits
; CHECK32-NEXT: .align 4
; CHECK32-NEXT: .short 1 # safe point count
; CHECK32-NEXT: .long .Ltmp0 # safe point address
; CHECK32-NEXT: .short 3 # stack frame size (in words)
; CHECK32-NEXT: .short 0 # stack arity
; CHECK32-NEXT: .short 0 # live root count
}
declare i32 @foo(i32)