R600/SI: Clean up checks for legality of immediate operands

There are new register classes VCSrc_* which represent operands that
can take an SGPR, VGPR or inline constant.  The VSrc_* class is now used
to represent operands that can take an SGPR, VGPR, or a 32-bit
immediate.

This allows us to have more accurate checks for legality of
immediates, since before we had no way to distinguish between operands
that supported any 32-bit immediate and operands which could only
support inline constants.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218334 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Tom Stellard 2014-09-23 21:26:25 +00:00
parent 30e7514d01
commit 33aca6d4a0
8 changed files with 149 additions and 67 deletions

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@ -85,21 +85,13 @@ MCCodeEmitter *llvm::createSIMCCodeEmitter(const MCInstrInfo &MCII,
bool SIMCCodeEmitter::isSrcOperand(const MCInstrDesc &Desc,
unsigned OpNo) const {
// FIXME: We need a better way to figure out which operands can be immediate
// values
//
// Some VOP* instructions like ADDC use VReg32 as the register class
// for source 0, because they read VCC and can't take an SGPR as an
// argument due to constant bus restrictions.
if (OpNo == 1 && (Desc.TSFlags & (SIInstrFlags::VOP1 | SIInstrFlags::VOP2 |
SIInstrFlags::VOPC)))
return true;
unsigned RegClass = Desc.OpInfo[OpNo].RegClass;
return (AMDGPU::SSrc_32RegClassID == RegClass) ||
(AMDGPU::SSrc_64RegClassID == RegClass) ||
(AMDGPU::VSrc_32RegClassID == RegClass) ||
(AMDGPU::VSrc_64RegClassID == RegClass);
(AMDGPU::VSrc_64RegClassID == RegClass) ||
(AMDGPU::VCSrc_32RegClassID == RegClass) ||
(AMDGPU::VCSrc_64RegClassID == RegClass);
}
uint32_t SIMCCodeEmitter::getLitEncoding(const MCOperand &MO) const {

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@ -1498,8 +1498,14 @@ SDValue SITargetLowering::PerformDAGCombine(SDNode *N,
/// \brief Test if RegClass is one of the VSrc classes
static bool isVSrc(unsigned RegClass) {
return AMDGPU::VSrc_32RegClassID == RegClass ||
AMDGPU::VSrc_64RegClassID == RegClass;
switch(RegClass) {
default: return false;
case AMDGPU::VSrc_32RegClassID:
case AMDGPU::VCSrc_32RegClassID:
case AMDGPU::VSrc_64RegClassID:
case AMDGPU::VCSrc_64RegClassID:
return true;
}
}
/// \brief Test if RegClass is one of the SSrc classes
@ -1611,10 +1617,9 @@ const TargetRegisterClass *SITargetLowering::getRegClassForNode(
// If the COPY_TO_REGCLASS instruction is copying to a VSrc register
// class, then the register class for the value could be either a
// VReg or and SReg. In order to get a more accurate
if (OpClassID == AMDGPU::VSrc_32RegClassID ||
OpClassID == AMDGPU::VSrc_64RegClassID) {
if (isVSrc(OpClassID))
return getRegClassForNode(DAG, Op.getOperand(0));
}
return TRI.getRegClass(OpClassID);
case AMDGPU::EXTRACT_SUBREG: {
int SubIdx = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();
@ -1648,14 +1653,23 @@ void SITargetLowering::ensureSRegLimit(SelectionDAG &DAG, SDValue &Operand,
unsigned RegClass,
bool &ScalarSlotUsed) const {
// First map the operands register class to a destination class
if (RegClass == AMDGPU::VSrc_32RegClassID)
RegClass = AMDGPU::VReg_32RegClassID;
else if (RegClass == AMDGPU::VSrc_64RegClassID)
RegClass = AMDGPU::VReg_64RegClassID;
else
if (!isVSrc(RegClass))
return;
// First map the operands register class to a destination class
switch (RegClass) {
case AMDGPU::VSrc_32RegClassID:
case AMDGPU::VCSrc_32RegClassID:
RegClass = AMDGPU::VReg_32RegClassID;
break;
case AMDGPU::VSrc_64RegClassID:
case AMDGPU::VCSrc_64RegClassID:
RegClass = AMDGPU::VReg_64RegClassID;
break;
default:
llvm_unreachable("Unknown vsrc reg class");
}
// Nothing to do if they fit naturally
if (fitsRegClass(DAG, Operand, RegClass))
return;
@ -1745,6 +1759,15 @@ SDNode *SITargetLowering::legalizeOperands(MachineSDNode *Node,
// No scalar allowed when we have both VSrc and SSrc
bool ScalarSlotUsed = HaveVSrc && HaveSSrc;
// If this instruction has an implicit use of VCC, then it can't use the
// constant bus.
for (unsigned i = 0, e = Desc->getNumImplicitUses(); i != e; ++i) {
if (Desc->ImplicitUses[i] == AMDGPU::VCC) {
ScalarSlotUsed = true;
break;
}
}
// Second go over the operands and try to fold them
std::vector<SDValue> Ops;
for (unsigned i = 0, e = Node->getNumOperands(), Op = NumDefs;

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@ -747,7 +747,7 @@ bool SIInstrInfo::isImmOperandLegal(const MachineInstr *MI, unsigned OpNo,
const MachineOperand &MO) const {
const MCOperandInfo &OpInfo = get(MI->getOpcode()).OpInfo[OpNo];
assert(MO.isImm() || MO.isFPImm());
assert(MO.isImm() || MO.isFPImm() || MO.isTargetIndex() || MO.isFI());
if (OpInfo.OperandType == MCOI::OPERAND_IMMEDIATE)
return true;
@ -755,7 +755,10 @@ bool SIInstrInfo::isImmOperandLegal(const MachineInstr *MI, unsigned OpNo,
if (OpInfo.RegClass < 0)
return false;
return RI.regClassCanUseImmediate(OpInfo.RegClass);
if (isLiteralConstant(MO))
return RI.regClassCanUseLiteralConstant(OpInfo.RegClass);
return RI.regClassCanUseInlineConstant(OpInfo.RegClass);
}
bool SIInstrInfo::canFoldOffset(unsigned OffsetSize, unsigned AS) {
@ -792,9 +795,41 @@ bool SIInstrInfo::hasModifiers(unsigned Opcode) const {
AMDGPU::OpName::src0_modifiers) != -1;
}
bool SIInstrInfo::usesConstantBus(const MachineRegisterInfo &MRI,
const MachineOperand &MO) const {
// Literal constants use the constant bus.
if (isLiteralConstant(MO))
return true;
if (!MO.isReg() || !MO.isUse())
return false;
if (TargetRegisterInfo::isVirtualRegister(MO.getReg()))
return RI.isSGPRClass(MRI.getRegClass(MO.getReg()));
// FLAT_SCR is just an SGPR pair.
if (!MO.isImplicit() && (MO.getReg() == AMDGPU::FLAT_SCR))
return true;
// EXEC register uses the constant bus.
if (!MO.isImplicit() && MO.getReg() == AMDGPU::EXEC)
return true;
// SGPRs use the constant bus
if (MO.getReg() == AMDGPU::M0 || MO.getReg() == AMDGPU::VCC ||
(!MO.isImplicit() &&
(AMDGPU::SGPR_32RegClass.contains(MO.getReg()) ||
AMDGPU::SGPR_64RegClass.contains(MO.getReg())))) {
return true;
}
return false;
}
bool SIInstrInfo::verifyInstruction(const MachineInstr *MI,
StringRef &ErrInfo) const {
uint16_t Opcode = MI->getOpcode();
const MachineRegisterInfo &MRI = MI->getParent()->getParent()->getRegInfo();
int Src0Idx = AMDGPU::getNamedOperandIdx(Opcode, AMDGPU::OpName::src0);
int Src1Idx = AMDGPU::getNamedOperandIdx(Opcode, AMDGPU::OpName::src1);
int Src2Idx = AMDGPU::getNamedOperandIdx(Opcode, AMDGPU::OpName::src2);
@ -811,19 +846,12 @@ bool SIInstrInfo::verifyInstruction(const MachineInstr *MI,
for (int i = 0, e = Desc.getNumOperands(); i != e; ++i) {
switch (Desc.OpInfo[i].OperandType) {
case MCOI::OPERAND_REGISTER: {
int RegClass = Desc.OpInfo[i].RegClass;
if (!RI.regClassCanUseImmediate(RegClass) &&
(MI->getOperand(i).isImm() || MI->getOperand(i).isFPImm())) {
// Handle some special cases:
// Src0 can of VOP1, VOP2, VOPC can be an immediate no matter what
// the register class.
if (i != Src0Idx || (!isVOP1(Opcode) && !isVOP2(Opcode) &&
!isVOPC(Opcode))) {
ErrInfo = "Expected register, but got immediate";
if ((MI->getOperand(i).isImm() || MI->getOperand(i).isFPImm()) &&
!isImmOperandLegal(MI, i, MI->getOperand(i))) {
ErrInfo = "Illegal immediate value for operand.";
return false;
}
}
}
break;
case MCOI::OPERAND_IMMEDIATE:
// Check if this operand is an immediate.
@ -863,31 +891,15 @@ bool SIInstrInfo::verifyInstruction(const MachineInstr *MI,
unsigned SGPRUsed = AMDGPU::NoRegister;
for (int i = 0, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
if (MO.isReg() && MO.isUse() &&
!TargetRegisterInfo::isVirtualRegister(MO.getReg())) {
// EXEC register uses the constant bus.
if (!MO.isImplicit() && MO.getReg() == AMDGPU::EXEC)
++ConstantBusCount;
// FLAT_SCR is just an SGPR pair.
if (!MO.isImplicit() && (MO.getReg() == AMDGPU::FLAT_SCR))
++ConstantBusCount;
// SGPRs use the constant bus
if (MO.getReg() == AMDGPU::M0 || MO.getReg() == AMDGPU::VCC ||
(!MO.isImplicit() &&
(AMDGPU::SGPR_32RegClass.contains(MO.getReg()) ||
AMDGPU::SGPR_64RegClass.contains(MO.getReg())))) {
if (SGPRUsed != MO.getReg()) {
if (usesConstantBus(MRI, MO)) {
if (MO.isReg()) {
if (MO.getReg() != SGPRUsed)
++ConstantBusCount;
SGPRUsed = MO.getReg();
}
SGPRUsed = MO.getReg();
} else {
++ConstantBusCount;
}
}
// Literal constants use the constant bus.
if (isLiteralConstant(MO))
++ConstantBusCount;
}
if (ConstantBusCount > 1) {
ErrInfo = "VOP* instruction uses the constant bus more than once";
@ -1136,6 +1148,18 @@ bool SIInstrInfo::isOperandLegal(const MachineInstr *MI, unsigned OpIdx,
if (!MO)
MO = &MI->getOperand(OpIdx);
if (usesConstantBus(MRI, *MO)) {
unsigned SGPRUsed = MO->isReg() ? MO->getReg() : AMDGPU::NoRegister;
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
if (i == OpIdx)
continue;
if (usesConstantBus(MRI, MI->getOperand(i)) &&
MI->getOperand(i).isReg() && MI->getOperand(i).getReg() != SGPRUsed) {
return false;
}
}
}
if (MO->isReg()) {
assert(DefinedRC);
const TargetRegisterClass *RC = MRI.getRegClass(MO->getReg());
@ -1151,7 +1175,7 @@ bool SIInstrInfo::isOperandLegal(const MachineInstr *MI, unsigned OpIdx,
return true;
}
return RI.regClassCanUseImmediate(DefinedRC);
return isImmOperandLegal(MI, OpIdx, *MO);
}
void SIInstrInfo::legalizeOperands(MachineInstr *MI) const {

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@ -132,6 +132,10 @@ public:
/// This function will return false if you pass it a 32-bit instruction.
bool hasVALU32BitEncoding(unsigned Opcode) const;
/// \brief Returns true if this operand uses the constant bus.
bool usesConstantBus(const MachineRegisterInfo &MRI,
const MachineOperand &MO) const;
/// \brief Return true if this instruction has any modifiers.
/// e.g. src[012]_mod, omod, clamp.
bool hasModifiers(unsigned Opcode) const;

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@ -361,7 +361,7 @@ class getInRC32 <list<ValueType> SrcVT> {
// Returns the register class to use for sources of VOP3 instructions for the
// given VT.
class getVOP3SrcForVT<ValueType VT> {
RegisterClass ret = !if(!eq(VT.Size, 32), VSrc_32, VSrc_64);
RegisterClass ret = !if(!eq(VT.Size, 32), VCSrc_32, VCSrc_64);
}
// Returns the register classes for the source arguments of a VOP3
@ -494,7 +494,7 @@ def VOP_F64_F64_I32 : VOPProfile <[f64, f64, i32, untyped]>;
def VOP_I32_F32_F32 : VOPProfile <[i32, f32, f32, untyped]>;
def VOP_I32_I32_I32 : VOPProfile <[i32, i32, i32, untyped]>;
def VOP_I32_I32_I32_VCC : VOPProfile <[i32, i32, i32, untyped]> {
let Src0RC32 = VReg_32;
let Src0RC32 = VCSrc_32;
}
def VOP_I64_I64_I32 : VOPProfile <[i64, i64, i32, untyped]>;
def VOP_I64_I64_I64 : VOPProfile <[i64, i64, i64, untyped]>;

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@ -275,7 +275,7 @@ unsigned SIRegisterInfo::getPhysRegSubReg(unsigned Reg,
return SubRC->getRegister(Index + Channel);
}
bool SIRegisterInfo::regClassCanUseImmediate(int RCID) const {
bool SIRegisterInfo::regClassCanUseLiteralConstant(int RCID) const {
switch (RCID) {
default: return false;
case AMDGPU::SSrc_32RegClassID:
@ -286,11 +286,29 @@ bool SIRegisterInfo::regClassCanUseImmediate(int RCID) const {
}
}
bool SIRegisterInfo::regClassCanUseImmediate(
bool SIRegisterInfo::regClassCanUseLiteralConstant(
const TargetRegisterClass *RC) const {
return regClassCanUseImmediate(RC->getID());
return regClassCanUseLiteralConstant(RC->getID());
}
bool SIRegisterInfo::regClassCanUseInlineConstant(int RCID) const {
if (regClassCanUseLiteralConstant(RCID))
return true;
switch (RCID) {
default: return false;
case AMDGPU::VCSrc_32RegClassID:
case AMDGPU::VCSrc_64RegClassID:
return true;
}
}
bool SIRegisterInfo::regClassCanUseInlineConstant(
const TargetRegisterClass *RC) const {
return regClassCanUseInlineConstant(RC->getID());
}
unsigned SIRegisterInfo::getPreloadedValue(const MachineFunction &MF,
enum PreloadedValue Value) const {

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@ -68,12 +68,21 @@ struct SIRegisterInfo : public AMDGPURegisterInfo {
unsigned Channel) const;
/// \returns True if operands defined with this register class can accept
/// inline immediates.
bool regClassCanUseImmediate(int RCID) const;
/// a literal constant (i.e. any 32-bit immediate).
bool regClassCanUseLiteralConstant(int RCID) const;
/// \returns True if operands defined with this register class can accept
/// inline immediates.
bool regClassCanUseImmediate(const TargetRegisterClass *RC) const;
/// a literal constant (i.e. any 32-bit immediate).
bool regClassCanUseLiteralConstant(const TargetRegisterClass *RC) const;
/// \returns True if operands defined with this register class can accept
/// an inline constant. i.e. An integer value in the range (-16, 64) or
/// -4.0f, -2.0f, -1.0f, -0.5f, 0.0f, 0.5f, 1.0f, 2.0f, 4.0f.
bool regClassCanUseInlineConstant(int RCID) const;
/// \returns True if operands defined with this register class can accept
/// a literal constant. i.e. A value in the range (-16, 64).
bool regClassCanUseInlineConstant(const TargetRegisterClass *RC) const;
enum PreloadedValue {
TGID_X,

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@ -210,17 +210,29 @@ def VReg_512 : RegisterClass<"AMDGPU", [v16i32, v16f32], 512, (add VGPR_512)>;
def VReg_1 : RegisterClass<"AMDGPU", [i1], 32, (add VGPR_32)>;
//===----------------------------------------------------------------------===//
// [SV]Src_(32|64) register classes, can have either an immediate or an register
// SSrc_* Operands with an SGPR or a 32-bit immediate
//===----------------------------------------------------------------------===//
def SSrc_32 : RegisterClass<"AMDGPU", [i32, f32], 32, (add SReg_32)>;
def SSrc_64 : RegisterClass<"AMDGPU", [i64, f64, i1], 64, (add SReg_64)>;
//===----------------------------------------------------------------------===//
// VSrc_* Operands with an SGPR, VGPR or a 32-bit immediate
//===----------------------------------------------------------------------===//
def VSrc_32 : RegisterClass<"AMDGPU", [i32, f32], 32, (add VReg_32, SReg_32)>;
def VSrc_64 : RegisterClass<"AMDGPU", [i64, f64], 64, (add VReg_64, SReg_64)>;
//===----------------------------------------------------------------------===//
// VCSrc_* Operands with an SGPR, VGPR or an inline constant
//===----------------------------------------------------------------------===//
def VCSrc_32 : RegisterClass<"AMDGPU", [i32, f32], 32, (add VReg_32, SReg_32)>;
def VCSrc_64 : RegisterClass<"AMDGPU", [i64, f64], 64, (add VReg_64, SReg_64)>;
//===----------------------------------------------------------------------===//
// SGPR and VGPR register classes
//===----------------------------------------------------------------------===//