llvm-for-llvmta/tools/llvm-exegesis/lib/PowerPC/Target.cpp

141 lines
5.1 KiB
C++

//===-- Target.cpp ----------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
// The PowerPC ExegesisTarget.
//===----------------------------------------------------------------------===//
#include "../Target.h"
#include "PPC.h"
#include "PPCRegisterInfo.h"
namespace llvm {
namespace exegesis {
// Helper to fill a memory operand with a value.
static void setMemOp(InstructionTemplate &IT, int OpIdx,
const MCOperand &OpVal) {
const auto Op = IT.getInstr().Operands[OpIdx];
assert(Op.isExplicit() && "invalid memory pattern");
IT.getValueFor(Op) = OpVal;
}
#include "PPCGenExegesis.inc"
namespace {
class ExegesisPowerPCTarget : public ExegesisTarget {
public:
ExegesisPowerPCTarget() : ExegesisTarget(PPCCpuPfmCounters) {}
private:
std::vector<MCInst> setRegTo(const MCSubtargetInfo &STI, unsigned Reg,
const APInt &Value) const override;
bool matchesArch(Triple::ArchType Arch) const override {
return Arch == Triple::ppc64le;
}
unsigned getScratchMemoryRegister(const Triple &) const override;
void fillMemoryOperands(InstructionTemplate &IT, unsigned Reg,
unsigned Offset) const override;
};
} // end anonymous namespace
static unsigned getLoadImmediateOpcode(unsigned RegBitWidth) {
switch (RegBitWidth) {
case 32:
return PPC::LI;
case 64:
return PPC::LI8;
}
llvm_unreachable("Invalid Value Width");
}
// Generates instruction to load an immediate value into a register.
static MCInst loadImmediate(unsigned Reg, unsigned RegBitWidth,
const APInt &Value) {
if (Value.getBitWidth() > RegBitWidth)
llvm_unreachable("Value must fit in the Register");
// We don't really care the value in reg, ignore the 16 bit
// restriction for now.
// TODO: make sure we get the exact value in reg if needed.
return MCInstBuilder(getLoadImmediateOpcode(RegBitWidth))
.addReg(Reg)
.addImm(Value.getZExtValue());
}
unsigned
ExegesisPowerPCTarget::getScratchMemoryRegister(const Triple &TT) const {
// R13 is reserved as Thread Pointer, we won't use threading in benchmark, so
// use it as scratch memory register
return TT.isArch64Bit() ? PPC::X13 : PPC::R13;
}
void ExegesisPowerPCTarget::fillMemoryOperands(InstructionTemplate &IT,
unsigned Reg,
unsigned Offset) const {
int MemOpIdx = 0;
if (IT.getInstr().hasTiedRegisters())
MemOpIdx = 1;
int DispOpIdx = MemOpIdx + 1;
const auto DispOp = IT.getInstr().Operands[DispOpIdx];
if (DispOp.isReg())
// We don't really care about the real address in snippets,
// So hardcode X1 for X-form Memory Operations for simplicity.
// TODO: materialize the offset into a reggister
setMemOp(IT, DispOpIdx, MCOperand::createReg(PPC::X1));
else
setMemOp(IT, DispOpIdx, MCOperand::createImm(Offset)); // Disp
setMemOp(IT, MemOpIdx + 2, MCOperand::createReg(Reg)); // BaseReg
}
std::vector<MCInst> ExegesisPowerPCTarget::setRegTo(const MCSubtargetInfo &STI,
unsigned Reg,
const APInt &Value) const {
// X11 is optional use in function linkage, should be the least used one
// Use it as scratch reg to load immediate.
unsigned ScratchImmReg = PPC::X11;
if (PPC::GPRCRegClass.contains(Reg))
return {loadImmediate(Reg, 32, Value)};
if (PPC::G8RCRegClass.contains(Reg))
return {loadImmediate(Reg, 64, Value)};
if (PPC::F4RCRegClass.contains(Reg))
return {loadImmediate(ScratchImmReg, 64, Value),
MCInstBuilder(PPC::MTVSRD).addReg(Reg).addReg(ScratchImmReg)};
// We don't care the real value in reg, so set 64 bits or duplicate 64 bits
// for simplicity.
// TODO: update these if we need a accurate 128 values in registers.
if (PPC::VRRCRegClass.contains(Reg))
return {loadImmediate(ScratchImmReg, 64, Value),
MCInstBuilder(PPC::MTVRD).addReg(Reg).addReg(ScratchImmReg)};
if (PPC::VSRCRegClass.contains(Reg))
return {loadImmediate(ScratchImmReg, 64, Value),
MCInstBuilder(PPC::MTVSRDD)
.addReg(Reg)
.addReg(ScratchImmReg)
.addReg(ScratchImmReg)};
if (PPC::VFRCRegClass.contains(Reg))
return {loadImmediate(ScratchImmReg, 64, Value),
MCInstBuilder(PPC::MTVSRD).addReg(Reg).addReg(ScratchImmReg)};
// SPE not supported yet
if (PPC::SPERCRegClass.contains(Reg)) {
errs() << "Unsupported SPE Reg:" << Reg << "\n";
return {};
}
errs() << "setRegTo is not implemented, results will be unreliable:" << Reg
<< "\n";
return {};
}
static ExegesisTarget *getTheExegesisPowerPCTarget() {
static ExegesisPowerPCTarget Target;
return &Target;
}
void InitializePowerPCExegesisTarget() {
ExegesisTarget::registerTarget(getTheExegesisPowerPCTarget());
}
} // namespace exegesis
} // namespace llvm