Files
archived-llvm/lib/Target/Sparc/SparcInstrInfo.cpp
James Y Knight 5b2a2849af [Sparc] Implement i64 load/store support for 32-bit sparc.
The LDD/STD instructions can load/store a 64bit quantity from/to
memory to/from a consecutive even/odd pair of (32-bit) registers. They
are part of SparcV8, and also present in SparcV9. (Although deprecated
there, as you can store 64bits in one register).

As recommended on llvmdev in the thread "How to enable use of 64bit
load/store for 32bit architecture" from Apr 2015, I've modeled the
64-bit load/store operations as working on a v2i32 type, rather than
making i64 a legal type, but with few legal operations. The latter
does not (currently) work, as there is much code in llvm which assumes
that if i64 is legal, operations like "add" will actually work on it.

The same assumption does not hold for v2i32 -- for vector types, it is
workable to support only load/store, and expand everything else.

This patch:
- Adds a new register class, IntPair, for even/odd pairs of registers.

- Modifies the list of reserved registers, the stack spilling code,
  and register copying code to support the IntPair register class.

- Adds support in AsmParser. (note that in asm text, you write the
  name of the first register of the pair only. So the parser has to
  morph the single register into the equivalent paired register).

- Adds the new instructions themselves (LDD/STD/LDDA/STDA).

- Hooks up the instructions and registers as a vector type v2i32. Adds
  custom legalizer to transform i64 load/stores into v2i32 load/stores
  and bitcasts, so that the new instructions can actually be
  generated, and marks all operations other than load/store on v2i32
  as needing to be expanded.

- Copies the unfortunate SelectInlineAsm hack from ARMISelDAGToDAG.
  This hack undoes the transformation of i64 operands into two
  arbitrarily-allocated separate i32 registers in
  SelectionDAGBuilder. and instead passes them in a single
  IntPair. (Arbitrarily allocated registers are not useful, asm code
  expects to be receiving a pair, which can be passed to ldd/std.)

Also adds a bunch of test cases covering all the bugs I've added along
the way.

Differential Revision: http://reviews.llvm.org/D8713

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@244484 91177308-0d34-0410-b5e6-96231b3b80d8
2015-08-10 19:11:39 +00:00

472 lines
16 KiB
C++

//===-- SparcInstrInfo.cpp - Sparc Instruction Information ----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the Sparc implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "SparcInstrInfo.h"
#include "Sparc.h"
#include "SparcMachineFunctionInfo.h"
#include "SparcSubtarget.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/TargetRegistry.h"
using namespace llvm;
#define GET_INSTRINFO_CTOR_DTOR
#include "SparcGenInstrInfo.inc"
// Pin the vtable to this file.
void SparcInstrInfo::anchor() {}
SparcInstrInfo::SparcInstrInfo(SparcSubtarget &ST)
: SparcGenInstrInfo(SP::ADJCALLSTACKDOWN, SP::ADJCALLSTACKUP), RI(),
Subtarget(ST) {}
/// isLoadFromStackSlot - If the specified machine instruction is a direct
/// load from a stack slot, return the virtual or physical register number of
/// the destination along with the FrameIndex of the loaded stack slot. If
/// not, return 0. This predicate must return 0 if the instruction has
/// any side effects other than loading from the stack slot.
unsigned SparcInstrInfo::isLoadFromStackSlot(const MachineInstr *MI,
int &FrameIndex) const {
if (MI->getOpcode() == SP::LDri ||
MI->getOpcode() == SP::LDXri ||
MI->getOpcode() == SP::LDFri ||
MI->getOpcode() == SP::LDDFri ||
MI->getOpcode() == SP::LDQFri) {
if (MI->getOperand(1).isFI() && MI->getOperand(2).isImm() &&
MI->getOperand(2).getImm() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
}
return 0;
}
/// isStoreToStackSlot - If the specified machine instruction is a direct
/// store to a stack slot, return the virtual or physical register number of
/// the source reg along with the FrameIndex of the loaded stack slot. If
/// not, return 0. This predicate must return 0 if the instruction has
/// any side effects other than storing to the stack slot.
unsigned SparcInstrInfo::isStoreToStackSlot(const MachineInstr *MI,
int &FrameIndex) const {
if (MI->getOpcode() == SP::STri ||
MI->getOpcode() == SP::STXri ||
MI->getOpcode() == SP::STFri ||
MI->getOpcode() == SP::STDFri ||
MI->getOpcode() == SP::STQFri) {
if (MI->getOperand(0).isFI() && MI->getOperand(1).isImm() &&
MI->getOperand(1).getImm() == 0) {
FrameIndex = MI->getOperand(0).getIndex();
return MI->getOperand(2).getReg();
}
}
return 0;
}
static bool IsIntegerCC(unsigned CC)
{
return (CC <= SPCC::ICC_VC);
}
static SPCC::CondCodes GetOppositeBranchCondition(SPCC::CondCodes CC)
{
switch(CC) {
case SPCC::ICC_A: return SPCC::ICC_N;
case SPCC::ICC_N: return SPCC::ICC_A;
case SPCC::ICC_NE: return SPCC::ICC_E;
case SPCC::ICC_E: return SPCC::ICC_NE;
case SPCC::ICC_G: return SPCC::ICC_LE;
case SPCC::ICC_LE: return SPCC::ICC_G;
case SPCC::ICC_GE: return SPCC::ICC_L;
case SPCC::ICC_L: return SPCC::ICC_GE;
case SPCC::ICC_GU: return SPCC::ICC_LEU;
case SPCC::ICC_LEU: return SPCC::ICC_GU;
case SPCC::ICC_CC: return SPCC::ICC_CS;
case SPCC::ICC_CS: return SPCC::ICC_CC;
case SPCC::ICC_POS: return SPCC::ICC_NEG;
case SPCC::ICC_NEG: return SPCC::ICC_POS;
case SPCC::ICC_VC: return SPCC::ICC_VS;
case SPCC::ICC_VS: return SPCC::ICC_VC;
case SPCC::FCC_A: return SPCC::FCC_N;
case SPCC::FCC_N: return SPCC::FCC_A;
case SPCC::FCC_U: return SPCC::FCC_O;
case SPCC::FCC_O: return SPCC::FCC_U;
case SPCC::FCC_G: return SPCC::FCC_ULE;
case SPCC::FCC_LE: return SPCC::FCC_UG;
case SPCC::FCC_UG: return SPCC::FCC_LE;
case SPCC::FCC_ULE: return SPCC::FCC_G;
case SPCC::FCC_L: return SPCC::FCC_UGE;
case SPCC::FCC_GE: return SPCC::FCC_UL;
case SPCC::FCC_UL: return SPCC::FCC_GE;
case SPCC::FCC_UGE: return SPCC::FCC_L;
case SPCC::FCC_LG: return SPCC::FCC_UE;
case SPCC::FCC_UE: return SPCC::FCC_LG;
case SPCC::FCC_NE: return SPCC::FCC_E;
case SPCC::FCC_E: return SPCC::FCC_NE;
}
llvm_unreachable("Invalid cond code");
}
bool SparcInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const
{
MachineBasicBlock::iterator I = MBB.end();
MachineBasicBlock::iterator UnCondBrIter = MBB.end();
while (I != MBB.begin()) {
--I;
if (I->isDebugValue())
continue;
// When we see a non-terminator, we are done.
if (!isUnpredicatedTerminator(I))
break;
// Terminator is not a branch.
if (!I->isBranch())
return true;
// Handle Unconditional branches.
if (I->getOpcode() == SP::BA) {
UnCondBrIter = I;
if (!AllowModify) {
TBB = I->getOperand(0).getMBB();
continue;
}
while (std::next(I) != MBB.end())
std::next(I)->eraseFromParent();
Cond.clear();
FBB = nullptr;
if (MBB.isLayoutSuccessor(I->getOperand(0).getMBB())) {
TBB = nullptr;
I->eraseFromParent();
I = MBB.end();
UnCondBrIter = MBB.end();
continue;
}
TBB = I->getOperand(0).getMBB();
continue;
}
unsigned Opcode = I->getOpcode();
if (Opcode != SP::BCOND && Opcode != SP::FBCOND)
return true; // Unknown Opcode.
SPCC::CondCodes BranchCode = (SPCC::CondCodes)I->getOperand(1).getImm();
if (Cond.empty()) {
MachineBasicBlock *TargetBB = I->getOperand(0).getMBB();
if (AllowModify && UnCondBrIter != MBB.end() &&
MBB.isLayoutSuccessor(TargetBB)) {
// Transform the code
//
// brCC L1
// ba L2
// L1:
// ..
// L2:
//
// into
//
// brnCC L2
// L1:
// ...
// L2:
//
BranchCode = GetOppositeBranchCondition(BranchCode);
MachineBasicBlock::iterator OldInst = I;
BuildMI(MBB, UnCondBrIter, MBB.findDebugLoc(I), get(Opcode))
.addMBB(UnCondBrIter->getOperand(0).getMBB()).addImm(BranchCode);
BuildMI(MBB, UnCondBrIter, MBB.findDebugLoc(I), get(SP::BA))
.addMBB(TargetBB);
OldInst->eraseFromParent();
UnCondBrIter->eraseFromParent();
UnCondBrIter = MBB.end();
I = MBB.end();
continue;
}
FBB = TBB;
TBB = I->getOperand(0).getMBB();
Cond.push_back(MachineOperand::CreateImm(BranchCode));
continue;
}
// FIXME: Handle subsequent conditional branches.
// For now, we can't handle multiple conditional branches.
return true;
}
return false;
}
unsigned
SparcInstrInfo::InsertBranch(MachineBasicBlock &MBB,MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
ArrayRef<MachineOperand> Cond,
DebugLoc DL) const {
assert(TBB && "InsertBranch must not be told to insert a fallthrough");
assert((Cond.size() == 1 || Cond.size() == 0) &&
"Sparc branch conditions should have one component!");
if (Cond.empty()) {
assert(!FBB && "Unconditional branch with multiple successors!");
BuildMI(&MBB, DL, get(SP::BA)).addMBB(TBB);
return 1;
}
// Conditional branch
unsigned CC = Cond[0].getImm();
if (IsIntegerCC(CC))
BuildMI(&MBB, DL, get(SP::BCOND)).addMBB(TBB).addImm(CC);
else
BuildMI(&MBB, DL, get(SP::FBCOND)).addMBB(TBB).addImm(CC);
if (!FBB)
return 1;
BuildMI(&MBB, DL, get(SP::BA)).addMBB(FBB);
return 2;
}
unsigned SparcInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const
{
MachineBasicBlock::iterator I = MBB.end();
unsigned Count = 0;
while (I != MBB.begin()) {
--I;
if (I->isDebugValue())
continue;
if (I->getOpcode() != SP::BA
&& I->getOpcode() != SP::BCOND
&& I->getOpcode() != SP::FBCOND)
break; // Not a branch
I->eraseFromParent();
I = MBB.end();
++Count;
}
return Count;
}
void SparcInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I, DebugLoc DL,
unsigned DestReg, unsigned SrcReg,
bool KillSrc) const {
unsigned numSubRegs = 0;
unsigned movOpc = 0;
const unsigned *subRegIdx = nullptr;
bool ExtraG0 = false;
const unsigned DW_SubRegsIdx[] = { SP::sub_even, SP::sub_odd };
const unsigned DFP_FP_SubRegsIdx[] = { SP::sub_even, SP::sub_odd };
const unsigned QFP_DFP_SubRegsIdx[] = { SP::sub_even64, SP::sub_odd64 };
const unsigned QFP_FP_SubRegsIdx[] = { SP::sub_even, SP::sub_odd,
SP::sub_odd64_then_sub_even,
SP::sub_odd64_then_sub_odd };
if (SP::IntRegsRegClass.contains(DestReg, SrcReg))
BuildMI(MBB, I, DL, get(SP::ORrr), DestReg).addReg(SP::G0)
.addReg(SrcReg, getKillRegState(KillSrc));
else if (SP::IntPairRegClass.contains(DestReg, SrcReg)) {
subRegIdx = DW_SubRegsIdx;
numSubRegs = 2;
movOpc = SP::ORrr;
ExtraG0 = true;
} else if (SP::FPRegsRegClass.contains(DestReg, SrcReg))
BuildMI(MBB, I, DL, get(SP::FMOVS), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc));
else if (SP::DFPRegsRegClass.contains(DestReg, SrcReg)) {
if (Subtarget.isV9()) {
BuildMI(MBB, I, DL, get(SP::FMOVD), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc));
} else {
// Use two FMOVS instructions.
subRegIdx = DFP_FP_SubRegsIdx;
numSubRegs = 2;
movOpc = SP::FMOVS;
}
} else if (SP::QFPRegsRegClass.contains(DestReg, SrcReg)) {
if (Subtarget.isV9()) {
if (Subtarget.hasHardQuad()) {
BuildMI(MBB, I, DL, get(SP::FMOVQ), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc));
} else {
// Use two FMOVD instructions.
subRegIdx = QFP_DFP_SubRegsIdx;
numSubRegs = 2;
movOpc = SP::FMOVD;
}
} else {
// Use four FMOVS instructions.
subRegIdx = QFP_FP_SubRegsIdx;
numSubRegs = 4;
movOpc = SP::FMOVS;
}
} else if (SP::ASRRegsRegClass.contains(DestReg) &&
SP::IntRegsRegClass.contains(SrcReg)) {
BuildMI(MBB, I, DL, get(SP::WRASRrr), DestReg)
.addReg(SP::G0)
.addReg(SrcReg, getKillRegState(KillSrc));
} else if (SP::IntRegsRegClass.contains(DestReg) &&
SP::ASRRegsRegClass.contains(SrcReg)) {
BuildMI(MBB, I, DL, get(SP::RDASR), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc));
} else
llvm_unreachable("Impossible reg-to-reg copy");
if (numSubRegs == 0 || subRegIdx == nullptr || movOpc == 0)
return;
const TargetRegisterInfo *TRI = &getRegisterInfo();
MachineInstr *MovMI = nullptr;
for (unsigned i = 0; i != numSubRegs; ++i) {
unsigned Dst = TRI->getSubReg(DestReg, subRegIdx[i]);
unsigned Src = TRI->getSubReg(SrcReg, subRegIdx[i]);
assert(Dst && Src && "Bad sub-register");
MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(movOpc), Dst);
if (ExtraG0)
MIB.addReg(SP::G0);
MIB.addReg(Src);
MovMI = MIB.getInstr();
}
// Add implicit super-register defs and kills to the last MovMI.
MovMI->addRegisterDefined(DestReg, TRI);
if (KillSrc)
MovMI->addRegisterKilled(SrcReg, TRI);
}
void SparcInstrInfo::
storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned SrcReg, bool isKill, int FI,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const {
DebugLoc DL;
if (I != MBB.end()) DL = I->getDebugLoc();
MachineFunction *MF = MBB.getParent();
const MachineFrameInfo &MFI = *MF->getFrameInfo();
MachineMemOperand *MMO =
MF->getMachineMemOperand(MachinePointerInfo::getFixedStack(FI),
MachineMemOperand::MOStore,
MFI.getObjectSize(FI),
MFI.getObjectAlignment(FI));
// On the order of operands here: think "[FrameIdx + 0] = SrcReg".
if (RC == &SP::I64RegsRegClass)
BuildMI(MBB, I, DL, get(SP::STXri)).addFrameIndex(FI).addImm(0)
.addReg(SrcReg, getKillRegState(isKill)).addMemOperand(MMO);
else if (RC == &SP::IntRegsRegClass)
BuildMI(MBB, I, DL, get(SP::STri)).addFrameIndex(FI).addImm(0)
.addReg(SrcReg, getKillRegState(isKill)).addMemOperand(MMO);
else if (RC == &SP::IntPairRegClass)
BuildMI(MBB, I, DL, get(SP::STDri)).addFrameIndex(FI).addImm(0)
.addReg(SrcReg, getKillRegState(isKill)).addMemOperand(MMO);
else if (RC == &SP::FPRegsRegClass)
BuildMI(MBB, I, DL, get(SP::STFri)).addFrameIndex(FI).addImm(0)
.addReg(SrcReg, getKillRegState(isKill)).addMemOperand(MMO);
else if (SP::DFPRegsRegClass.hasSubClassEq(RC))
BuildMI(MBB, I, DL, get(SP::STDFri)).addFrameIndex(FI).addImm(0)
.addReg(SrcReg, getKillRegState(isKill)).addMemOperand(MMO);
else if (SP::QFPRegsRegClass.hasSubClassEq(RC))
// Use STQFri irrespective of its legality. If STQ is not legal, it will be
// lowered into two STDs in eliminateFrameIndex.
BuildMI(MBB, I, DL, get(SP::STQFri)).addFrameIndex(FI).addImm(0)
.addReg(SrcReg, getKillRegState(isKill)).addMemOperand(MMO);
else
llvm_unreachable("Can't store this register to stack slot");
}
void SparcInstrInfo::
loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned DestReg, int FI,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const {
DebugLoc DL;
if (I != MBB.end()) DL = I->getDebugLoc();
MachineFunction *MF = MBB.getParent();
const MachineFrameInfo &MFI = *MF->getFrameInfo();
MachineMemOperand *MMO =
MF->getMachineMemOperand(MachinePointerInfo::getFixedStack(FI),
MachineMemOperand::MOLoad,
MFI.getObjectSize(FI),
MFI.getObjectAlignment(FI));
if (RC == &SP::I64RegsRegClass)
BuildMI(MBB, I, DL, get(SP::LDXri), DestReg).addFrameIndex(FI).addImm(0)
.addMemOperand(MMO);
else if (RC == &SP::IntRegsRegClass)
BuildMI(MBB, I, DL, get(SP::LDri), DestReg).addFrameIndex(FI).addImm(0)
.addMemOperand(MMO);
else if (RC == &SP::IntPairRegClass)
BuildMI(MBB, I, DL, get(SP::LDDri), DestReg).addFrameIndex(FI).addImm(0)
.addMemOperand(MMO);
else if (RC == &SP::FPRegsRegClass)
BuildMI(MBB, I, DL, get(SP::LDFri), DestReg).addFrameIndex(FI).addImm(0)
.addMemOperand(MMO);
else if (SP::DFPRegsRegClass.hasSubClassEq(RC))
BuildMI(MBB, I, DL, get(SP::LDDFri), DestReg).addFrameIndex(FI).addImm(0)
.addMemOperand(MMO);
else if (SP::QFPRegsRegClass.hasSubClassEq(RC))
// Use LDQFri irrespective of its legality. If LDQ is not legal, it will be
// lowered into two LDDs in eliminateFrameIndex.
BuildMI(MBB, I, DL, get(SP::LDQFri), DestReg).addFrameIndex(FI).addImm(0)
.addMemOperand(MMO);
else
llvm_unreachable("Can't load this register from stack slot");
}
unsigned SparcInstrInfo::getGlobalBaseReg(MachineFunction *MF) const
{
SparcMachineFunctionInfo *SparcFI = MF->getInfo<SparcMachineFunctionInfo>();
unsigned GlobalBaseReg = SparcFI->getGlobalBaseReg();
if (GlobalBaseReg != 0)
return GlobalBaseReg;
// Insert the set of GlobalBaseReg into the first MBB of the function
MachineBasicBlock &FirstMBB = MF->front();
MachineBasicBlock::iterator MBBI = FirstMBB.begin();
MachineRegisterInfo &RegInfo = MF->getRegInfo();
const TargetRegisterClass *PtrRC =
Subtarget.is64Bit() ? &SP::I64RegsRegClass : &SP::IntRegsRegClass;
GlobalBaseReg = RegInfo.createVirtualRegister(PtrRC);
DebugLoc dl;
BuildMI(FirstMBB, MBBI, dl, get(SP::GETPCX), GlobalBaseReg);
SparcFI->setGlobalBaseReg(GlobalBaseReg);
return GlobalBaseReg;
}