LLVM  6.0.0svn
ARMMacroFusion.cpp
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1 //===- ARMMacroFusion.cpp - ARM Macro Fusion ----------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 /// \file This file contains the ARM implementation of the DAG scheduling
11 /// mutation to pair instructions back to back.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "ARMMacroFusion.h"
16 #include "ARMSubtarget.h"
19 
20 namespace llvm {
21 
22 /// \brief Check if the instr pair, FirstMI and SecondMI, should be fused
23 /// together. Given SecondMI, when FirstMI is unspecified, then check if
24 /// SecondMI may be part of a fused pair at all.
26  const TargetSubtargetInfo &TSI,
27  const MachineInstr *FirstMI,
28  const MachineInstr &SecondMI) {
29  const ARMSubtarget &ST = static_cast<const ARMSubtarget&>(TSI);
30 
31  // Assume wildcards for unspecified instrs.
32  unsigned FirstOpcode =
33  FirstMI ? FirstMI->getOpcode()
34  : static_cast<unsigned>(ARM::INSTRUCTION_LIST_END);
35  unsigned SecondOpcode = SecondMI.getOpcode();
36 
37  if (ST.hasFuseAES())
38  // Fuse AES crypto operations.
39  switch(SecondOpcode) {
40  // AES encode.
41  case ARM::AESMC :
42  return FirstOpcode == ARM::AESE ||
43  FirstOpcode == ARM::INSTRUCTION_LIST_END;
44  // AES decode.
45  case ARM::AESIMC:
46  return FirstOpcode == ARM::AESD ||
47  FirstOpcode == ARM::INSTRUCTION_LIST_END;
48  }
49 
50  return false;
51 }
52 
53 std::unique_ptr<ScheduleDAGMutation> createARMMacroFusionDAGMutation () {
55 }
56 
57 } // end namespace llvm
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
bool hasFuseAES() const
Definition: ARMSubtarget.h:595
const HexagonInstrInfo * TII
unsigned getOpcode() const
Returns the opcode of this MachineInstr.
Definition: MachineInstr.h:290
std::unique_ptr< ScheduleDAGMutation > createMacroFusionDAGMutation(ShouldSchedulePredTy shouldScheduleAdjacent)
Create a DAG scheduling mutation to pair instructions back to back for instructions that benefit acco...
std::unique_ptr< ScheduleDAGMutation > createARMMacroFusionDAGMutation()
Note that you have to add: DAG.addMutation(createARMMacroFusionDAGMutation()); to ARMPassConfig::crea...
TargetInstrInfo - Interface to description of machine instruction set.
static bool shouldScheduleAdjacent(const TargetInstrInfo &TII, const TargetSubtargetInfo &TSI, const MachineInstr *FirstMI, const MachineInstr &SecondMI)
Check if the instr pair, FirstMI and SecondMI, should be fused together.
TargetSubtargetInfo - Generic base class for all target subtargets.
Representation of each machine instruction.
Definition: MachineInstr.h:59