xref: /freebsd/contrib/llvm-project/llvm/lib/Target/AMDGPU/AMDGPUMacroFusion.cpp (revision 5f757f3ff9144b609b3c433dfd370cc6bdc191ad)
10b57cec5SDimitry Andric //===--- AMDGPUMacroFusion.cpp - AMDGPU Macro Fusion ----------------------===//
20b57cec5SDimitry Andric //
30b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
40b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
50b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
60b57cec5SDimitry Andric //
70b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
80b57cec5SDimitry Andric //
90b57cec5SDimitry Andric /// \file This file contains the AMDGPU implementation of the DAG scheduling
100b57cec5SDimitry Andric ///  mutation to pair instructions back to back.
110b57cec5SDimitry Andric //
120b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
130b57cec5SDimitry Andric 
140b57cec5SDimitry Andric #include "AMDGPUMacroFusion.h"
150b57cec5SDimitry Andric #include "MCTargetDesc/AMDGPUMCTargetDesc.h"
16*e8d8bef9SDimitry Andric #include "SIInstrInfo.h"
170b57cec5SDimitry Andric #include "llvm/CodeGen/MacroFusion.h"
180b57cec5SDimitry Andric 
190b57cec5SDimitry Andric using namespace llvm;
200b57cec5SDimitry Andric 
210b57cec5SDimitry Andric namespace {
220b57cec5SDimitry Andric 
230b57cec5SDimitry Andric /// Check if the instr pair, FirstMI and SecondMI, should be fused
240b57cec5SDimitry Andric /// together. Given SecondMI, when FirstMI is unspecified, then check if
250b57cec5SDimitry Andric /// SecondMI may be part of a fused pair at all.
260b57cec5SDimitry Andric static bool shouldScheduleAdjacent(const TargetInstrInfo &TII_,
270b57cec5SDimitry Andric                                    const TargetSubtargetInfo &TSI,
280b57cec5SDimitry Andric                                    const MachineInstr *FirstMI,
290b57cec5SDimitry Andric                                    const MachineInstr &SecondMI) {
300b57cec5SDimitry Andric   const SIInstrInfo &TII = static_cast<const SIInstrInfo&>(TII_);
310b57cec5SDimitry Andric 
320b57cec5SDimitry Andric   switch (SecondMI.getOpcode()) {
330b57cec5SDimitry Andric   case AMDGPU::V_ADDC_U32_e64:
340b57cec5SDimitry Andric   case AMDGPU::V_SUBB_U32_e64:
355ffd83dbSDimitry Andric   case AMDGPU::V_SUBBREV_U32_e64:
360b57cec5SDimitry Andric   case AMDGPU::V_CNDMASK_B32_e64: {
370b57cec5SDimitry Andric     // Try to cluster defs of condition registers to their uses. This improves
380b57cec5SDimitry Andric     // the chance VCC will be available which will allow shrinking to VOP2
390b57cec5SDimitry Andric     // encodings.
400b57cec5SDimitry Andric     if (!FirstMI)
410b57cec5SDimitry Andric       return true;
420b57cec5SDimitry Andric 
430b57cec5SDimitry Andric     const MachineBasicBlock &MBB = *FirstMI->getParent();
440b57cec5SDimitry Andric     const MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
450b57cec5SDimitry Andric     const TargetRegisterInfo *TRI = MRI.getTargetRegisterInfo();
460b57cec5SDimitry Andric     const MachineOperand *Src2 = TII.getNamedOperand(SecondMI,
470b57cec5SDimitry Andric                                                      AMDGPU::OpName::src2);
480b57cec5SDimitry Andric     return FirstMI->definesRegister(Src2->getReg(), TRI);
490b57cec5SDimitry Andric   }
500b57cec5SDimitry Andric   default:
510b57cec5SDimitry Andric     return false;
520b57cec5SDimitry Andric   }
530b57cec5SDimitry Andric 
540b57cec5SDimitry Andric   return false;
550b57cec5SDimitry Andric }
560b57cec5SDimitry Andric 
570b57cec5SDimitry Andric } // end namespace
580b57cec5SDimitry Andric 
590b57cec5SDimitry Andric 
600b57cec5SDimitry Andric namespace llvm {
610b57cec5SDimitry Andric 
620b57cec5SDimitry Andric std::unique_ptr<ScheduleDAGMutation> createAMDGPUMacroFusionDAGMutation() {
630b57cec5SDimitry Andric   return createMacroFusionDAGMutation(shouldScheduleAdjacent);
640b57cec5SDimitry Andric }
650b57cec5SDimitry Andric 
660b57cec5SDimitry Andric } // end namespace llvm
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