llvm/lib/Target/SystemZ/SystemZAsmPrinter.cpp
Richard Sandiford 086791eca2 Add TargetLowering::prepareVolatileOrAtomicLoad
One unusual feature of the z architecture is that the result of a
previous load can be reused indefinitely for subsequent loads, even if
a cache-coherent store to that location is performed by another CPU.
A special serializing instruction must be used if you want to force
a load to be reattempted.

Since volatile loads are not supposed to be omitted in this way,
we should insert a serializing instruction before each such load.
The same goes for atomic loads.

The patch implements this at the IR->DAG boundary, in a similar way
to atomic fences.  It is a no-op for targets other than SystemZ.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196905 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-10 10:36:34 +00:00

249 lines
8.0 KiB
C++

//===-- SystemZAsmPrinter.cpp - SystemZ LLVM assembly printer -------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Streams SystemZ assembly language and associated data, in the form of
// MCInsts and MCExprs respectively.
//
//===----------------------------------------------------------------------===//
#include "SystemZAsmPrinter.h"
#include "InstPrinter/SystemZInstPrinter.h"
#include "SystemZConstantPoolValue.h"
#include "SystemZMCInstLower.h"
#include "llvm/CodeGen/MachineModuleInfoImpls.h"
#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInstBuilder.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Target/Mangler.h"
using namespace llvm;
// Return an RI instruction like MI with opcode Opcode, but with the
// GR64 register operands turned into GR32s.
static MCInst lowerRILow(const MachineInstr *MI, unsigned Opcode) {
if (MI->isCompare())
return MCInstBuilder(Opcode)
.addReg(SystemZMC::getRegAsGR32(MI->getOperand(0).getReg()))
.addImm(MI->getOperand(1).getImm());
else
return MCInstBuilder(Opcode)
.addReg(SystemZMC::getRegAsGR32(MI->getOperand(0).getReg()))
.addReg(SystemZMC::getRegAsGR32(MI->getOperand(1).getReg()))
.addImm(MI->getOperand(2).getImm());
}
// Return an RI instruction like MI with opcode Opcode, but with the
// GR64 register operands turned into GRH32s.
static MCInst lowerRIHigh(const MachineInstr *MI, unsigned Opcode) {
if (MI->isCompare())
return MCInstBuilder(Opcode)
.addReg(SystemZMC::getRegAsGRH32(MI->getOperand(0).getReg()))
.addImm(MI->getOperand(1).getImm());
else
return MCInstBuilder(Opcode)
.addReg(SystemZMC::getRegAsGRH32(MI->getOperand(0).getReg()))
.addReg(SystemZMC::getRegAsGRH32(MI->getOperand(1).getReg()))
.addImm(MI->getOperand(2).getImm());
}
// Return an RI instruction like MI with opcode Opcode, but with the
// R2 register turned into a GR64.
static MCInst lowerRIEfLow(const MachineInstr *MI, unsigned Opcode) {
return MCInstBuilder(Opcode)
.addReg(MI->getOperand(0).getReg())
.addReg(MI->getOperand(1).getReg())
.addReg(SystemZMC::getRegAsGR64(MI->getOperand(2).getReg()))
.addImm(MI->getOperand(3).getImm())
.addImm(MI->getOperand(4).getImm())
.addImm(MI->getOperand(5).getImm());
}
void SystemZAsmPrinter::EmitInstruction(const MachineInstr *MI) {
SystemZMCInstLower Lower(MF->getContext(), *this);
MCInst LoweredMI;
switch (MI->getOpcode()) {
case SystemZ::Return:
LoweredMI = MCInstBuilder(SystemZ::BR).addReg(SystemZ::R14D);
break;
case SystemZ::CallBRASL:
LoweredMI = MCInstBuilder(SystemZ::BRASL)
.addReg(SystemZ::R14D)
.addExpr(Lower.getExpr(MI->getOperand(0), MCSymbolRefExpr::VK_PLT));
break;
case SystemZ::CallBASR:
LoweredMI = MCInstBuilder(SystemZ::BASR)
.addReg(SystemZ::R14D)
.addReg(MI->getOperand(0).getReg());
break;
case SystemZ::CallJG:
LoweredMI = MCInstBuilder(SystemZ::JG)
.addExpr(Lower.getExpr(MI->getOperand(0), MCSymbolRefExpr::VK_PLT));
break;
case SystemZ::CallBR:
LoweredMI = MCInstBuilder(SystemZ::BR).addReg(SystemZ::R1D);
break;
case SystemZ::IILF64:
LoweredMI = MCInstBuilder(SystemZ::IILF)
.addReg(SystemZMC::getRegAsGR32(MI->getOperand(0).getReg()))
.addImm(MI->getOperand(2).getImm());
break;
case SystemZ::IIHF64:
LoweredMI = MCInstBuilder(SystemZ::IIHF)
.addReg(SystemZMC::getRegAsGRH32(MI->getOperand(0).getReg()))
.addImm(MI->getOperand(2).getImm());
break;
case SystemZ::RISBHH:
case SystemZ::RISBHL:
LoweredMI = lowerRIEfLow(MI, SystemZ::RISBHG);
break;
case SystemZ::RISBLH:
case SystemZ::RISBLL:
LoweredMI = lowerRIEfLow(MI, SystemZ::RISBLG);
break;
#define LOWER_LOW(NAME) \
case SystemZ::NAME##64: LoweredMI = lowerRILow(MI, SystemZ::NAME); break
LOWER_LOW(IILL);
LOWER_LOW(IILH);
LOWER_LOW(TMLL);
LOWER_LOW(TMLH);
LOWER_LOW(NILL);
LOWER_LOW(NILH);
LOWER_LOW(NILF);
LOWER_LOW(OILL);
LOWER_LOW(OILH);
LOWER_LOW(OILF);
LOWER_LOW(XILF);
#undef LOWER_LOW
#define LOWER_HIGH(NAME) \
case SystemZ::NAME##64: LoweredMI = lowerRIHigh(MI, SystemZ::NAME); break
LOWER_HIGH(IIHL);
LOWER_HIGH(IIHH);
LOWER_HIGH(TMHL);
LOWER_HIGH(TMHH);
LOWER_HIGH(NIHL);
LOWER_HIGH(NIHH);
LOWER_HIGH(NIHF);
LOWER_HIGH(OIHL);
LOWER_HIGH(OIHH);
LOWER_HIGH(OIHF);
LOWER_HIGH(XIHF);
#undef LOWER_HIGH
case SystemZ::Serialize:
if (Subtarget->hasFastSerialization())
LoweredMI = MCInstBuilder(SystemZ::AsmBCR)
.addImm(14).addReg(SystemZ::R0D);
else
LoweredMI = MCInstBuilder(SystemZ::AsmBCR)
.addImm(15).addReg(SystemZ::R0D);
break;
default:
Lower.lower(MI, LoweredMI);
break;
}
OutStreamer.EmitInstruction(LoweredMI);
}
// Convert a SystemZ-specific constant pool modifier into the associated
// MCSymbolRefExpr variant kind.
static MCSymbolRefExpr::VariantKind
getModifierVariantKind(SystemZCP::SystemZCPModifier Modifier) {
switch (Modifier) {
case SystemZCP::NTPOFF: return MCSymbolRefExpr::VK_NTPOFF;
}
llvm_unreachable("Invalid SystemCPModifier!");
}
void SystemZAsmPrinter::
EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
SystemZConstantPoolValue *ZCPV =
static_cast<SystemZConstantPoolValue*>(MCPV);
const MCExpr *Expr =
MCSymbolRefExpr::Create(getSymbol(ZCPV->getGlobalValue()),
getModifierVariantKind(ZCPV->getModifier()),
OutContext);
uint64_t Size = TM.getDataLayout()->getTypeAllocSize(ZCPV->getType());
OutStreamer.EmitValue(Expr, Size);
}
bool SystemZAsmPrinter::PrintAsmOperand(const MachineInstr *MI,
unsigned OpNo,
unsigned AsmVariant,
const char *ExtraCode,
raw_ostream &OS) {
if (ExtraCode && *ExtraCode == 'n') {
if (!MI->getOperand(OpNo).isImm())
return true;
OS << -int64_t(MI->getOperand(OpNo).getImm());
} else {
SystemZMCInstLower Lower(MF->getContext(), *this);
MCOperand MO(Lower.lowerOperand(MI->getOperand(OpNo)));
SystemZInstPrinter::printOperand(MO, OS);
}
return false;
}
bool SystemZAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
unsigned OpNo,
unsigned AsmVariant,
const char *ExtraCode,
raw_ostream &OS) {
SystemZInstPrinter::printAddress(MI->getOperand(OpNo).getReg(),
MI->getOperand(OpNo + 1).getImm(),
MI->getOperand(OpNo + 2).getReg(), OS);
return false;
}
void SystemZAsmPrinter::EmitEndOfAsmFile(Module &M) {
if (Subtarget->isTargetELF()) {
const TargetLoweringObjectFileELF &TLOFELF =
static_cast<const TargetLoweringObjectFileELF &>(getObjFileLowering());
MachineModuleInfoELF &MMIELF = MMI->getObjFileInfo<MachineModuleInfoELF>();
// Output stubs for external and common global variables.
MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
if (!Stubs.empty()) {
OutStreamer.SwitchSection(TLOFELF.getDataRelSection());
const DataLayout *TD = TM.getDataLayout();
for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
OutStreamer.EmitLabel(Stubs[i].first);
OutStreamer.EmitSymbolValue(Stubs[i].second.getPointer(),
TD->getPointerSize(0));
}
Stubs.clear();
}
}
}
// Force static initialization.
extern "C" void LLVMInitializeSystemZAsmPrinter() {
RegisterAsmPrinter<SystemZAsmPrinter> X(TheSystemZTarget);
}