llvm-project/llvm/lib/Target/ARM/ARMMacroFusion.cpp

58 lines
1.9 KiB
C++

//===- ARMMacroFusion.cpp - ARM Macro Fusion ----------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
/// \file This file contains the ARM implementation of the DAG scheduling
/// mutation to pair instructions back to back.
//
//===----------------------------------------------------------------------===//
#include "ARMMacroFusion.h"
#include "ARMSubtarget.h"
#include "llvm/CodeGen/MacroFusion.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
namespace llvm {
/// \brief Check if the instr pair, FirstMI and SecondMI, should be fused
/// together. Given SecondMI, when FirstMI is unspecified, then check if
/// SecondMI may be part of a fused pair at all.
static bool shouldScheduleAdjacent(const TargetInstrInfo &TII,
const TargetSubtargetInfo &TSI,
const MachineInstr *FirstMI,
const MachineInstr &SecondMI) {
const ARMSubtarget &ST = static_cast<const ARMSubtarget&>(TSI);
// Assume wildcards for unspecified instrs.
unsigned FirstOpcode =
FirstMI ? FirstMI->getOpcode()
: static_cast<unsigned>(ARM::INSTRUCTION_LIST_END);
unsigned SecondOpcode = SecondMI.getOpcode();
if (ST.hasFuseAES())
// Fuse AES crypto operations.
switch(SecondOpcode) {
// AES encode.
case ARM::AESMC :
return FirstOpcode == ARM::AESE ||
FirstOpcode == ARM::INSTRUCTION_LIST_END;
// AES decode.
case ARM::AESIMC:
return FirstOpcode == ARM::AESD ||
FirstOpcode == ARM::INSTRUCTION_LIST_END;
}
return false;
}
std::unique_ptr<ScheduleDAGMutation> createARMMacroFusionDAGMutation () {
return createMacroFusionDAGMutation(shouldScheduleAdjacent);
}
} // end namespace llvm