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1 /* |
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2 * Copyright 1997-2005 Sun Microsystems, Inc. All Rights Reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. |
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8 * |
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9 * This code is distributed in the hope that it will be useful, but WITHOUT |
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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12 * version 2 for more details (a copy is included in the LICENSE file that |
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13 * accompanied this code). |
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14 * |
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15 * You should have received a copy of the GNU General Public License version |
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16 * 2 along with this work; if not, write to the Free Software Foundation, |
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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18 * |
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19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
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20 * CA 95054 USA or visit www.sun.com if you need additional information or |
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21 * have any questions. |
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22 * |
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23 */ |
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24 |
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25 #include "incls/_precompiled.incl" |
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26 #include "incls/_rootnode.cpp.incl" |
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27 |
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28 //------------------------------Ideal------------------------------------------ |
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29 // Remove dead inputs |
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30 Node *RootNode::Ideal(PhaseGVN *phase, bool can_reshape) { |
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31 for( uint i = 1; i < req(); i++ ) { // For all inputs |
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32 // Check for and remove dead inputs |
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33 if( phase->type(in(i)) == Type::TOP ) { |
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34 del_req(i--); // Delete TOP inputs |
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35 } |
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36 } |
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37 |
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38 // I used to do tail-splitting in the Ideal graph here, but it does not |
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39 // work. The tail-splitting forces values live into the Return to be |
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40 // ready at a point which dominates the split returns. This forces Stores |
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41 // to be hoisted high. The "proper" fix would be to split Stores down |
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42 // each path, but this makes the split unprofitable. If we want to do this |
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43 // optimization, it needs to be done after allocation so we can count all |
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44 // the instructions needing to be cloned in the cost metric. |
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45 |
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46 // There used to be a spoof here for caffeine marks which completely |
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47 // eliminated very simple self-recursion recursions, but it's not worth it. |
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48 // Deep inlining of self-calls gets nearly all of the same benefits. |
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49 // If we want to get the rest of the win later, we should pattern match |
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50 // simple recursive call trees to closed-form solutions. |
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51 |
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52 return NULL; // No further opportunities exposed |
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53 } |
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54 |
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55 //============================================================================= |
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56 HaltNode::HaltNode( Node *ctrl, Node *frameptr ) : Node(TypeFunc::Parms) { |
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57 Node* top = Compile::current()->top(); |
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58 init_req(TypeFunc::Control, ctrl ); |
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59 init_req(TypeFunc::I_O, top); |
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60 init_req(TypeFunc::Memory, top); |
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61 init_req(TypeFunc::FramePtr, frameptr ); |
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62 init_req(TypeFunc::ReturnAdr,top); |
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63 } |
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64 |
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65 const Type *HaltNode::bottom_type() const { return Type::BOTTOM; } |
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66 |
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67 //------------------------------Ideal------------------------------------------ |
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68 Node *HaltNode::Ideal(PhaseGVN *phase, bool can_reshape) { |
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69 return remove_dead_region(phase, can_reshape) ? this : NULL; |
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70 } |
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71 |
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72 //------------------------------Value------------------------------------------ |
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73 const Type *HaltNode::Value( PhaseTransform *phase ) const { |
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74 return ( phase->type(in(TypeFunc::Control)) == Type::TOP) |
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75 ? Type::TOP |
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76 : Type::BOTTOM; |
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77 } |
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78 |
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79 const RegMask &HaltNode::out_RegMask() const { |
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80 return RegMask::Empty; |
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81 } |