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-rw-r--r--lib/Target/PIC16/PIC16MemSelOpt.cpp254
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diff --git a/lib/Target/PIC16/PIC16MemSelOpt.cpp b/lib/Target/PIC16/PIC16MemSelOpt.cpp
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--- a/lib/Target/PIC16/PIC16MemSelOpt.cpp
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-//===-- PIC16MemSelOpt.cpp - PIC16 banksel optimizer --------------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file defines the pass which optimizes the emitting of banksel
-// instructions before accessing data memory. This currently works within
-// a basic block only and keep tracks of the last accessed memory bank.
-// If memory access continues to be in the same bank it just makes banksel
-// immediate, which is a part of the insn accessing the data memory, from 1
-// to zero. The asm printer emits a banksel only if that immediate is 1.
-//
-// FIXME: this is not implemented yet. The banksel pass only works on local
-// basic blocks.
-//
-//===----------------------------------------------------------------------===//
-
-#define DEBUG_TYPE "pic16-codegen"
-#include "PIC16.h"
-#include "PIC16ABINames.h"
-#include "PIC16InstrInfo.h"
-#include "PIC16MCAsmInfo.h"
-#include "PIC16TargetMachine.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/Target/TargetInstrInfo.h"
-#include "llvm/Target/TargetMachine.h"
-#include "llvm/GlobalValue.h"
-#include "llvm/DerivedTypes.h"
-
-using namespace llvm;
-
-namespace {
- struct MemSelOpt : public MachineFunctionPass {
- static char ID;
- MemSelOpt() : MachineFunctionPass(ID) {}
-
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addPreservedID(MachineLoopInfoID);
- AU.addPreservedID(MachineDominatorsID);
- MachineFunctionPass::getAnalysisUsage(AU);
- }
-
- virtual bool runOnMachineFunction(MachineFunction &MF);
-
- virtual const char *getPassName() const {
- return "PIC16 Memsel Optimizer";
- }
-
- bool processBasicBlock(MachineFunction &MF, MachineBasicBlock &MBB);
- bool processInstruction(MachineInstr *MI);
-
- private:
- const TargetInstrInfo *TII; // Machine instruction info.
- MachineBasicBlock *MBB; // Current basic block
- std::string CurBank;
- int PageChanged;
-
- };
- char MemSelOpt::ID = 0;
-}
-
-FunctionPass *llvm::createPIC16MemSelOptimizerPass() {
- return new MemSelOpt();
-}
-
-
-/// runOnMachineFunction - Loop over all of the basic blocks, transforming FP
-/// register references into FP stack references.
-///
-bool MemSelOpt::runOnMachineFunction(MachineFunction &MF) {
- TII = MF.getTarget().getInstrInfo();
- bool Changed = false;
- for (MachineFunction::iterator I = MF.begin(), E = MF.end();
- I != E; ++I) {
- Changed |= processBasicBlock(MF, *I);
- }
-
- return Changed;
-}
-
-/// processBasicBlock - Loop over all of the instructions in the basic block,
-/// transforming FP instructions into their stack form.
-///
-bool MemSelOpt::processBasicBlock(MachineFunction &MF, MachineBasicBlock &BB) {
- bool Changed = false;
- MBB = &BB;
-
- // Let us assume that when entering a basic block now bank is selected.
- // Ideally we should look at the predecessors for this information.
- CurBank="";
- PageChanged=0;
-
- MachineBasicBlock::iterator I;
- for (I = BB.begin(); I != BB.end(); ++I) {
- Changed |= processInstruction(I);
-
- // if the page has changed insert a page sel before
- // any instruction that needs one
- if (PageChanged == 1)
- {
- // Restore the page if it was changed, before leaving the basic block,
- // because it may be required by the goto terminator or the fall thru
- // basic blcok.
- // If the terminator is return, we don't need to restore since there
- // is no goto or fall thru basic block.
- if ((I->getOpcode() == PIC16::sublw_3) || //macro has goto
- (I->getOpcode() == PIC16::sublw_6) || //macro has goto
- (I->getOpcode() == PIC16::addlwc) || //macro has goto
- (TII->get(I->getOpcode()).isBranch()))
- {
- DebugLoc dl = I->getDebugLoc();
- BuildMI(*MBB, I, dl, TII->get(PIC16::pagesel)).addExternalSymbol("$");
- Changed = true;
- PageChanged = 0;
- }
- }
- }
-
- // The basic block is over, but if we did not find any goto yet,
- // we haven't restored the page.
- // Restore the page if it was changed, before leaving the basic block,
- // because it may be required by fall thru basic blcok.
- // If the terminator is return, we don't need to restore since there
- // is fall thru basic block.
- if (PageChanged == 1) {
- // save the end pointer before we move back to last insn.
- MachineBasicBlock::iterator J = I;
- I--;
- const TargetInstrDesc &TID = TII->get(I->getOpcode());
- if (! TID.isReturn())
- {
- DebugLoc dl = I->getDebugLoc();
- BuildMI(*MBB, J, dl,
- TII->get(PIC16::pagesel)).addExternalSymbol("$");
- Changed = true;
- PageChanged = 0;
- }
- }
-
-
- return Changed;
-}
-
-bool MemSelOpt::processInstruction(MachineInstr *MI) {
- bool Changed = false;
-
- unsigned NumOperands = MI->getNumOperands();
- if (NumOperands == 0) return false;
-
-
- // If this insn is not going to access any memory, return.
- const TargetInstrDesc &TID = TII->get(MI->getOpcode());
- if (!(TID.isBranch() || TID.isCall() || TID.mayLoad() || TID.mayStore()))
- return false;
-
- // The first thing we should do is that record if banksel/pagesel are
- // changed in an unknown way. This can happend via any type of call.
- // We do it here first before scanning of MemOp / BBOp as the indirect
- // call insns do not have any operands, but they still may change bank/page.
- if (TID.isCall()) {
- // Record that we have changed the page, so that we can restore it
- // before basic block ends.
- // We require to signal that a page anc bank change happened even for
- // indirect calls.
- PageChanged = 1;
-
- // When a call is made, there may be banksel for variables in callee.
- // Hence the banksel in caller needs to be reset.
- CurBank = "";
- }
-
- // Scan for the memory address operand.
- // FIXME: Should we use standard interfaces like memoperands_iterator,
- // hasMemOperand() etc ?
- int MemOpPos = -1;
- int BBOpPos = -1;
- for (unsigned i = 0; i < NumOperands; i++) {
- MachineOperand Op = MI->getOperand(i);
- if (Op.getType() == MachineOperand::MO_GlobalAddress ||
- Op.getType() == MachineOperand::MO_ExternalSymbol) {
- // We found one mem operand. Next one may be BS.
- MemOpPos = i;
- }
- if (Op.getType() == MachineOperand::MO_MachineBasicBlock) {
- // We found one BB operand. Next one may be pagesel.
- BBOpPos = i;
- }
- }
-
- // If we did not find an insn accessing memory. Continue.
- if ((MemOpPos == -1) &&
- (BBOpPos == -1))
- return false;
- assert ((BBOpPos != MemOpPos) && "operand can only be of one type");
-
-
- // If this is a pagesel material, handle it first.
- // CALL and br_ucond insns use MemOp (GA or ES) and not BBOp.
- // Pagesel is required only for a direct call.
- if ((MI->getOpcode() == PIC16::CALL)) {
- // Get the BBOp.
- MachineOperand &MemOp = MI->getOperand(MemOpPos);
- DebugLoc dl = MI->getDebugLoc();
- BuildMI(*MBB, MI, dl, TII->get(PIC16::pagesel)).addOperand(MemOp);
-
- // CALL and br_ucond needs only pagesel. so we are done.
- return true;
- }
-
- // Pagesel is handled. Now, add a Banksel if needed.
- if (MemOpPos == -1) return Changed;
- // Get the MemOp.
- MachineOperand &Op = MI->getOperand(MemOpPos);
-
- // Get the section name(NewBank) for MemOp.
- // This assumes that the section names for globals are already set by
- // AsmPrinter->doInitialization.
- std::string NewBank = CurBank;
- bool hasExternalLinkage = false;
- if (Op.getType() == MachineOperand::MO_GlobalAddress &&
- Op.getGlobal()->getType()->getAddressSpace() == PIC16ISD::RAM_SPACE) {
- if (Op.getGlobal()->hasExternalLinkage())
- hasExternalLinkage= true;
- NewBank = Op.getGlobal()->getSection();
- } else if (Op.getType() == MachineOperand::MO_ExternalSymbol) {
- // External Symbol is generated for temp data and arguments. They are
- // in fpdata.<functionname>.# section.
- std::string Sym = Op.getSymbolName();
- NewBank = PAN::getSectionNameForSym(Sym);
- }
-
- // If the section is shared section, do not emit banksel.
- if (NewBank == PAN::getSharedUDataSectionName())
- return Changed;
-
- // If the previous and new section names are same, we don't need to
- // emit banksel.
- if (NewBank.compare(CurBank) != 0 || hasExternalLinkage) {
- DebugLoc dl = MI->getDebugLoc();
- BuildMI(*MBB, MI, dl, TII->get(PIC16::banksel)).
- addOperand(Op);
- Changed = true;
- CurBank = NewBank;
- }
-
- return Changed;
-}
-
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