| //===------ LeonPasses.cpp - Define passes specific to LEON ---------------===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "LeonPasses.h" |
| #include "SparcSubtarget.h" |
| #include "llvm/CodeGen/MachineBasicBlock.h" |
| #include "llvm/CodeGen/MachineFunction.h" |
| #include "llvm/CodeGen/MachineInstr.h" |
| #include "llvm/CodeGen/MachineInstrBuilder.h" |
| #include "llvm/Support/raw_ostream.h" |
| |
| using namespace llvm; |
| |
| LEONMachineFunctionPass::LEONMachineFunctionPass(char &ID) |
| : MachineFunctionPass(ID) {} |
| |
| //***************************************************************************** |
| //**** InsertNOPLoad pass |
| //***************************************************************************** |
| // This pass fixes the incorrectly working Load instructions that exists for |
| // some earlier versions of the LEON processor line. NOP instructions must |
| // be inserted after the load instruction to ensure that the Load instruction |
| // behaves as expected for these processors. |
| // |
| // This pass inserts a NOP after any LD or LDF instruction. |
| // |
| char InsertNOPLoad::ID = 0; |
| |
| InsertNOPLoad::InsertNOPLoad() : LEONMachineFunctionPass(ID) {} |
| |
| bool InsertNOPLoad::runOnMachineFunction(MachineFunction &MF) { |
| Subtarget = &MF.getSubtarget<SparcSubtarget>(); |
| const TargetInstrInfo &TII = *Subtarget->getInstrInfo(); |
| DebugLoc DL = DebugLoc(); |
| |
| bool Modified = false; |
| for (MachineBasicBlock &MBB : MF) { |
| for (auto MBBI = MBB.begin(), E = MBB.end(); MBBI != E; ++MBBI) { |
| MachineInstr &MI = *MBBI; |
| unsigned Opcode = MI.getOpcode(); |
| if (Opcode >= SP::LDDArr && Opcode <= SP::LDrr) { |
| MachineBasicBlock::iterator NMBBI = std::next(MBBI); |
| BuildMI(MBB, NMBBI, DL, TII.get(SP::NOP)); |
| Modified = true; |
| } |
| } |
| } |
| |
| return Modified; |
| } |
| |
| |
| |
| //***************************************************************************** |
| //**** DetectRoundChange pass |
| //***************************************************************************** |
| // To prevent any explicit change of the default rounding mode, this pass |
| // detects any call of the fesetround function. |
| // A warning is generated to ensure the user knows this has happened. |
| // |
| // Detects an erratum in UT699 LEON 3 processor |
| |
| char DetectRoundChange::ID = 0; |
| |
| DetectRoundChange::DetectRoundChange() : LEONMachineFunctionPass(ID) {} |
| |
| bool DetectRoundChange::runOnMachineFunction(MachineFunction &MF) { |
| Subtarget = &MF.getSubtarget<SparcSubtarget>(); |
| |
| bool Modified = false; |
| for (MachineBasicBlock &MBB : MF) { |
| for (MachineInstr &MI : MBB) { |
| unsigned Opcode = MI.getOpcode(); |
| if (Opcode == SP::CALL && MI.getNumOperands() > 0) { |
| MachineOperand &MO = MI.getOperand(0); |
| |
| if (MO.isGlobal()) { |
| StringRef FuncName = MO.getGlobal()->getName(); |
| if (FuncName.compare_insensitive("fesetround") == 0) { |
| errs() << "Error: You are using the detectroundchange " |
| "option to detect rounding changes that will " |
| "cause LEON errata. The only way to fix this " |
| "is to remove the call to fesetround from " |
| "the source code.\n"; |
| } |
| } |
| } |
| } |
| } |
| |
| return Modified; |
| } |
| |
| //***************************************************************************** |
| //**** FixAllFDIVSQRT pass |
| //***************************************************************************** |
| // This pass fixes the incorrectly working FDIVx and FSQRTx instructions that |
| // exist for some earlier versions of the LEON processor line. Five NOP |
| // instructions need to be inserted after these instructions to ensure the |
| // correct result is placed in the destination registers before they are used. |
| // |
| // This pass implements two fixes: |
| // 1) fixing the FSQRTS and FSQRTD instructions. |
| // 2) fixing the FDIVS and FDIVD instructions. |
| // |
| // FSQRTS and FDIVS are converted to FDIVD and FSQRTD respectively earlier in |
| // the pipeline when this option is enabled, so this pass needs only to deal |
| // with the changes that still need implementing for the "double" versions |
| // of these instructions. |
| // |
| char FixAllFDIVSQRT::ID = 0; |
| |
| FixAllFDIVSQRT::FixAllFDIVSQRT() : LEONMachineFunctionPass(ID) {} |
| |
| bool FixAllFDIVSQRT::runOnMachineFunction(MachineFunction &MF) { |
| Subtarget = &MF.getSubtarget<SparcSubtarget>(); |
| const TargetInstrInfo &TII = *Subtarget->getInstrInfo(); |
| DebugLoc DL = DebugLoc(); |
| |
| bool Modified = false; |
| for (MachineBasicBlock &MBB : MF) { |
| for (auto MBBI = MBB.begin(), E = MBB.end(); MBBI != E; ++MBBI) { |
| MachineInstr &MI = *MBBI; |
| unsigned Opcode = MI.getOpcode(); |
| |
| // Note: FDIVS and FSQRTS cannot be generated when this erratum fix is |
| // switched on so we don't need to check for them here. They will |
| // already have been converted to FSQRTD or FDIVD earlier in the |
| // pipeline. |
| if (Opcode == SP::FSQRTD || Opcode == SP::FDIVD) { |
| for (int InsertedCount = 0; InsertedCount < 5; InsertedCount++) |
| BuildMI(MBB, MBBI, DL, TII.get(SP::NOP)); |
| |
| MachineBasicBlock::iterator NMBBI = std::next(MBBI); |
| for (int InsertedCount = 0; InsertedCount < 28; InsertedCount++) |
| BuildMI(MBB, NMBBI, DL, TII.get(SP::NOP)); |
| |
| Modified = true; |
| } |
| } |
| } |
| |
| return Modified; |
| } |