TCEFrameInfo.hh

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/*
    Copyright (c) 2002-2010 Tampere University.
 
    This file is part of TTA-Based Codesign Environment (TCE).
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
    to deal in the Software without restriction, including without limitation
    the rights to use, copy, modify, merge, publish, distribute, sublicense,
    and/or sell copies of the Software, and to permit persons to whom the
    Software is furnished to do so, subject to the following conditions:
 
    The above copyright notice and this permission notice shall be included in
    all copies or substantial portions of the Software.
 
    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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 */
/**
 * @file TCEFrameInfo.hh
 *
 * Declaration of TCEFrameLowering class.
 *
 * @author Heikki Kultala 2010 (hkultala-no.spam-cs.tut.fi)
 */
 
#ifndef TCE_FRAME_INFO_H
#define TCE_FRAME_INFO_H
 
#include "tce_config.h"
 
#include <llvm/Support/ErrorHandling.h>
#include <llvm/CodeGen/TargetFrameLowering.h>
#include "TCERegisterInfo.hh"
#include "TCEInstrInfo.hh"
 
namespace llvm {
 
    /** !! Important !! *************
     * ON EVERY LLVM UPDATE CHECK THESE INTERFACES VERY CAREFULLY
     * FROM include/llvm/Target/TargetFrameInfo.h
     *
     * Compiler doesn warn or give error if parameter lists are changed.
     * Many times also base class implementation works, but does not do
     * very good job.
     */
 
//  Frame info:
// -------------
// Grows down, alignment at least 4 bytes. The alignment is set according to
// the widest operand in the machine.
//
 
 
    class TCEFrameLowering : public TargetFrameLowering {
    public:
 
    /** !! Important !! *************
     * If the last boolean parameter of the constructor is set to false, 
     * stack realignment is not allowed. This means, that every stack object
     * having a bigger alignment than the stack's own alignment, will be 
     * reduced to have the stack's alignment.
     * 
     * For example, if stack realignment parameter is set to false, and 
     * stack has alignment of 4, and v4i32 vector has alignment of 16 
     * (bytes) -> vector's alignment in stack will be demoted to 4.
     */
        TCEFrameLowering(
            TCERegisterInfo* tri,
            const TCEInstrInfo* tii,
            int stackAlignment) :
        // The -stackAlignment is local area offset.
        // Storing RA to stack consumes one slot,
        // so local are offset begins below it.
        TargetFrameLowering(
            StackGrowsDown, Align(stackAlignment), -stackAlignment),
        tri_(tri), tii_(*tii), stackAlignment_(stackAlignment) {
            tri->setTFI(this);
        }
 
        MachineBasicBlock::iterator
        eliminateCallFramePseudoInstr(
            MachineFunction &MF,
            MachineBasicBlock &MBB,
            MachineBasicBlock::iterator I) const override;
 
    void emitPrologue(MachineFunction &mf, MachineBasicBlock &MBB) const override;
        void emitEpilogue(MachineFunction &mf, MachineBasicBlock &MBB) const override;
        bool hasFP(const MachineFunction &MF) const override;
        int stackAlignment() const { return stackAlignment_; }
        bool containsCall(const MachineFunction& mf) const;
    private:
        int stackAlignment_;
        const TCERegisterInfo* tri_;
        const TCEInstrInfo& tii_;
    };
} // /namespace
 
#endif