Ejemplo n.º 1
0
  public void unbox(Map<Variable, TemporaryLocalVariable> unboxMap) {
    // System.out.println("BB : " + basicBlock + " in " + this.problem.getScope().getName());
    // System.out.println("-- known types on entry:");
    // for (Variable v: inState.types.keySet()) {
    //     if (inState.types.get(v) != Object.class) {
    //         System.out.println(v + "-->" + inState.types.get(v));
    //     }
    // }
    // System.out.print("-- unboxed vars on entry:");
    // for (Variable v: inState.unboxedVars) {
    //     System.out.print(" " + v);
    // }
    // System.out.println("------");
    // System.out.print("-- unboxed vars on exit:");
    // for (Variable v: outState.unboxedVars) {
    //     System.out.print(" " + v);
    // }
    // System.out.println("------");

    // Compute UNION(unboxedVarsIn(all-successors)) - this.unboxedVarsOut
    // All vars in this new set have to be unboxed on exit from this BB
    boolean scopeBindingHasEscaped = problem.getScope().bindingHasEscaped();
    Set<Variable> succUnboxedVars = new HashSet<Variable>();
    CFG cfg = problem.getScope().cfg();

    for (Edge e : cfg.getOutgoingEdges(basicBlock)) {
      BasicBlock b = (BasicBlock) e.getDestination().getData();
      if (b != cfg.getExitBB()) {
        UnboxableOpsAnalysisNode x = (UnboxableOpsAnalysisNode) problem.getFlowGraphNode(b);
        succUnboxedVars.addAll(x.inState.unboxedVars);
      }
    }

    succUnboxedVars.removeAll(outState.unboxedVars);

    // Only worry about vars live on exit from the BB
    LiveVariablesProblem lvp =
        (LiveVariablesProblem) problem.getScope().getDataFlowSolution(DataFlowConstants.LVP_NAME);
    BitSet liveVarsSet = ((LiveVariableNode) lvp.getFlowGraphNode(basicBlock)).getLiveInBitSet();

    // Rescue node, if any
    IRScope scope = this.problem.getScope();
    boolean isClosure = scope instanceof IRClosure;

    List<Instr> newInstrs = new ArrayList<Instr>();
    boolean unboxedLiveVars = false;

    initSolution();

    for (Instr i : basicBlock.getInstrs()) {
      Variable dst = null;
      boolean dirtied = false;
      boolean hitDFBarrier = false;
      // System.out.println("ORIG: " + i);
      if (i.getOperation().transfersControl()) {
        // Add unboxing instrs.
        for (Variable v : succUnboxedVars) {
          if (liveVarsSet.get(lvp.getDFVar(v).getId())) {
            // System.out.println("suv: UNBOXING for " + v);
            newInstrs.add(new UnboxFloatInstr(getUnboxedVar(unboxMap, v), v));
            tmpState.unboxedVars.add(v);
          }
        }
        unboxedLiveVars = true;
      } else {
        if (i instanceof ResultInstr) {
          dst = ((ResultInstr) i).getResult();
        }

        if (i instanceof CopyInstr) {
          // Copies are easy
          Operand src = ((CopyInstr) i).getSource();
          Class srcType = getOperandType(tmpState, src);
          setOperandType(tmpState, dst, srcType);

          // If we have an unboxed type for 'src', we can leave this unboxed.
          //
          // FIXME: However, if 'src' is a constant, this could unnecessarily
          // leave 'src' unboxed and lead to a boxing instruction further down
          // at the use site of 'dst'. This indicates that leaving this unboxed
          // should ideally be done 'on-demand'. This indicates that this could
          // be a backward-flow algo OR that this algo should be run on a
          // dataflow graph / SSA graph.
          if (srcType == Float.class) {
            Operand unboxedSrc =
                src instanceof Variable ? getUnboxedVar(unboxMap, (Variable) src) : src;
            TemporaryLocalVariable unboxedDst = getUnboxedVar(unboxMap, dst);
            newInstrs.add(new CopyInstr(Operation.COPY_UNBOXED, unboxedDst, unboxedSrc));
            dirtied = true;
          }
        } else if (i instanceof CallBase) {
          // Process calls specially -- these are what we want to optimize!
          CallBase c = (CallBase) i;
          Operand o = c.getClosureArg(null);
          if (o == null) {
            MethAddr m = c.getMethodAddr();
            Operand r = c.getReceiver();
            Operand[] args = c.getCallArgs();
            if (args.length == 1 && m.resemblesALUOp()) {
              Operand a = args[0];
              Class receiverType = getOperandType(tmpState, r);
              Class argType = getOperandType(tmpState, a);
              // Optimistically assume that call is an ALU op
              if (receiverType == Float.class
                  || (receiverType == Fixnum.class && argType == Float.class)) {
                setOperandType(tmpState, dst, Float.class);
                r = getUnboxedOperand(tmpState.unboxedVars, unboxMap, r, newInstrs);
                a = getUnboxedOperand(tmpState.unboxedVars, unboxMap, a, newInstrs);
                TemporaryLocalVariable unboxedDst = getUnboxedVar(unboxMap, dst);
                newInstrs.add(new AluInstr(m.getUnboxedOp(Float.class), unboxedDst, r, a));
                dirtied = true;
              } else {
                if (receiverType == Fixnum.class && argType == Fixnum.class) {
                  setOperandType(tmpState, dst, Fixnum.class);
                } else {
                  setOperandType(tmpState, dst, Object.class);
                }

                if (c.targetRequiresCallersBinding()) {
                  hitDFBarrier = true;
                }
              }
            } else {
              setOperandType(tmpState, dst, Object.class);
            }
          } else {
            if (o instanceof WrappedIRClosure) {
              // Since binding can escape in arbitrary ways in the general case,
              // assume the worst for now. If we are guaranteed that the closure binding
              // is not used outside the closure itself, we can avoid worst-case behavior.
              hitDFBarrier = true;

              // Fetch the nested unboxing-analysis problem, creating one if necessary
              IRClosure cl = ((WrappedIRClosure) o).getClosure();
              UnboxableOpsAnalysisProblem subProblem =
                  (UnboxableOpsAnalysisProblem) cl.getDataFlowSolution(DataFlowConstants.UNBOXING);
              UnboxableOpsAnalysisNode exitNode =
                  (UnboxableOpsAnalysisNode) subProblem.getExitNode();

              // Compute solution
              subProblem.unbox();

              // Update types to MEET(new-state-on-exit, current-state)
              tmpState.computeMEETForTypes(exitNode.outState, true);

              // As for unboxed var state, since binding can escape in
              // arbitrary ways in the general case, assume the worst for now.
              // If we are guaranteed that the closure binding is not used
              // outside the closure itself, we can avoid worst-case behavior
              // and only clear vars that are modified in the closure.
              hitDFBarrier = true;
            } else {
              // Cannot analyze
              hitDFBarrier = true;
            }
          }
        } else {
          // We dont know how to optimize this instruction.
          // So, we assume we dont know type of the result.
          // TOP/class --> BOTTOM
          setOperandType(tmpState, dst, Object.class);
        }
      }

      if (dirtied) {
        tmpState.unboxedVars.add(dst);
        tmpState.unboxedDirtyVars.add(dst);
      } else {
        // Since the instruction didn't run in unboxed form,
        // dirty unboxed vars will have to get boxed here.
        boxRequiredVars(
            i, tmpState, unboxMap, dst, hasExceptionsRescued(), hitDFBarrier, newInstrs);
      }
    }

    // Add unboxing instrs.
    if (!unboxedLiveVars) {
      for (Variable v : succUnboxedVars) {
        if (liveVarsSet.get(lvp.getDFVar(v).getId())) {
          // System.out.println("suv: UNBOXING for " + v);
          newInstrs.add(new UnboxFloatInstr(getUnboxedVar(unboxMap, v), v));
        }
      }
    }

    /*
            System.out.println("------");
            for (Instr i : newInstrs) {
                System.out.println("NEW: " + i);
            }
    */

    basicBlock.replaceInstrs(newInstrs);
  }
  public void unbox(Map<Variable, TemporaryLocalVariable> unboxMap) {
    // System.out.println("BB : " + basicBlock + " in " + problem.getScope().getName());
    // System.out.println("-- known types on entry:");
    // for (Variable v: inState.types.keySet()) {
    //     if (inState.types.get(v) != Object.class) {
    //         System.out.println(v + "-->" + inState.types.get(v));
    //     }
    // }
    // System.out.print("-- unboxed vars on entry:");
    // for (Variable v: inState.unboxedVars) {
    //     System.out.print(" " + v);
    // }
    // System.out.println("------");
    // System.out.print("-- unboxed vars on exit:");
    // for (Variable v: outState.unboxedVars) {
    //     System.out.print(" " + v);
    // }
    // System.out.println("------");

    CFG cfg = getCFG();

    // Compute UNION(unboxedVarsIn(all-successors)) - this.unboxedVarsOut
    // All vars in this new set have to be unboxed on exit from this BB
    HashMap<Variable, Class> succUnboxedVars = new HashMap<Variable, Class>();
    for (BasicBlock b : cfg.getOutgoingDestinations(basicBlock)) {
      if (b.isExitBB()) continue;

      Map<Variable, Class> xVars = problem.getFlowGraphNode(b).inState.unboxedVars;
      for (Variable v2 : xVars.keySet()) {
        // VERY IMPORTANT: Pay attention!
        //
        // Technically, the successors of this node may not all agree on what
        // the unboxed type ought to be for 'v2'. For example, one successor might
        // want 'v2' in Fixnum form and other might want it in Float form. If that
        // happens, we have to add unboxing instructions for each of those expected
        // types. However, for now, we are going to punt and assume that our successors
        // agree on unboxed types for 'v2'.
        succUnboxedVars.put(v2, xVars.get(v2));
      }
    }

    // Same caveat as above applies here
    for (Variable v3 : outState.unboxedVars.keySet()) {
      succUnboxedVars.remove(v3);
    }

    // Only worry about vars live on exit from the BB
    LiveVariablesProblem lvp =
        (LiveVariablesProblem) problem.getScope().getDataFlowSolution(DataFlowConstants.LVP_NAME);
    BitSet liveVarsSet = lvp.getFlowGraphNode(basicBlock).getLiveInBitSet();

    List<Instr> newInstrs = new ArrayList<Instr>();
    boolean unboxedLiveVars = false;

    initSolution();

    for (Instr i : basicBlock.getInstrs()) {
      Variable dst = null;
      boolean dirtied = false;
      boolean hitDFBarrier = false;
      // System.out.println("ORIG: " + i);
      if (i.getOperation().transfersControl()) {
        // Add unboxing instrs.
        for (Variable v : succUnboxedVars.keySet()) {
          if (liveVarsSet.get(lvp.getDFVar(v))) {
            unboxVar(tmpState, succUnboxedVars.get(v), unboxMap, v, newInstrs);
          }
        }
        unboxedLiveVars = true;
      } else {
        if (i instanceof ResultInstr) {
          dst = ((ResultInstr) i).getResult();
        }

        if (i instanceof CopyInstr) {
          // Copies are easy
          Operand src = ((CopyInstr) i).getSource();
          Class srcType = getOperandType(tmpState, src);
          setOperandType(tmpState, dst, srcType);

          // If we have an unboxed type for 'src', we can leave this unboxed.
          //
          // FIXME: However, if 'src' is a constant, this could unnecessarily
          // leave 'src' unboxed and lead to a boxing instruction further down
          // at the use site of 'dst'. This indicates that leaving this unboxed
          // should ideally be done 'on-demand'. This indicates that this could
          // be a backward-flow algo OR that this algo should be run on a
          // dataflow graph / SSA graph.
          if (srcType == Float.class || srcType == Fixnum.class) {
            Operand unboxedSrc =
                src instanceof Variable ? getUnboxedVar(srcType, unboxMap, (Variable) src) : src;
            TemporaryLocalVariable unboxedDst = getUnboxedVar(srcType, unboxMap, dst);
            newInstrs.add(new CopyInstr(Operation.COPY, unboxedDst, unboxedSrc));
            tmpState.unboxedVars.put(dst, srcType);
            dirtied = true;
          }
        } else if (i instanceof ClosureAcceptingInstr) {
          Operand o = ((ClosureAcceptingInstr) i).getClosureArg();
          if (i instanceof CallBase && o == null) {
            CallBase c = (CallBase) i;
            MethAddr m = c.getMethodAddr();
            Operand r = c.getReceiver();
            Operand[] args = c.getCallArgs();
            if (dst != null && args.length == 1 && m.resemblesALUOp()) {
              Operand a = args[0];
              Class receiverType = getOperandType(tmpState, r);
              Class argType = getOperandType(tmpState, a);
              // Optimistically assume that call is an ALU op
              Operation unboxedOp;
              if ((receiverType == Float.class
                      || (receiverType == Fixnum.class && argType == Float.class))
                  && (unboxedOp = m.getUnboxedOp(Float.class)) != null) {
                dirtied = true;

                Class dstType = m.getUnboxedResultType(Float.class);
                setOperandType(tmpState, dst, dstType);
                tmpState.unboxedVars.put(dst, dstType);

                TemporaryLocalVariable unboxedDst = getUnboxedVar(dstType, unboxMap, dst);
                r = unboxOperand(tmpState, Float.class, unboxMap, r, newInstrs);
                a = unboxOperand(tmpState, Float.class, unboxMap, a, newInstrs);
                newInstrs.add(new AluInstr(unboxedOp, unboxedDst, r, a));
              } else if ((receiverType == Float.class
                      || (receiverType == Fixnum.class && argType == Fixnum.class))
                  && (unboxedOp = m.getUnboxedOp(Fixnum.class)) != null) {
                dirtied = true;

                Class dstType = m.getUnboxedResultType(Fixnum.class);
                setOperandType(tmpState, dst, dstType);
                tmpState.unboxedVars.put(dst, dstType);

                TemporaryLocalVariable unboxedDst = getUnboxedVar(dstType, unboxMap, dst);
                r = unboxOperand(tmpState, Fixnum.class, unboxMap, r, newInstrs);
                a = unboxOperand(tmpState, Fixnum.class, unboxMap, a, newInstrs);
                newInstrs.add(new AluInstr(unboxedOp, unboxedDst, r, a));
              } else {
                if (receiverType == Fixnum.class && argType == Fixnum.class) {
                  setOperandType(tmpState, dst, Fixnum.class);
                } else {
                  setOperandType(tmpState, dst, Object.class);
                }

                if (c.targetRequiresCallersBinding()) {
                  hitDFBarrier = true;
                }
              }
            } else {
              setOperandType(tmpState, dst, Object.class);
            }
          } else {
            if (o instanceof WrappedIRClosure) {
              // Since binding can escape in arbitrary ways in the general case,
              // assume the worst for now. If we are guaranteed that the closure binding
              // is not used outside the closure itself, we can avoid worst-case behavior.
              hitDFBarrier = true;

              // Fetch the nested unboxing-analysis problem, creating one if necessary
              IRClosure cl = ((WrappedIRClosure) o).getClosure();
              UnboxableOpsAnalysisProblem subProblem =
                  (UnboxableOpsAnalysisProblem) cl.getDataFlowSolution(DataFlowConstants.UNBOXING);
              UnboxableOpsAnalysisNode exitNode = subProblem.getExitNode();

              // Compute solution
              subProblem.unbox();

              // Update types to MEET(new-state-on-exit, current-state)
              tmpState.computeMEETForTypes(exitNode.outState, true);

              // As for unboxed var state, since binding can escape in
              // arbitrary ways in the general case, assume the worst for now.
              // If we are guaranteed that the closure binding is not used
              // outside the closure itself, we can avoid worst-case behavior
              // and only clear vars that are modified in the closure.
              hitDFBarrier = true;
            } else {
              // Cannot analyze
              hitDFBarrier = true;
            }
          }
        } else {
          // We dont know how to optimize this instruction.
          // So, we assume we dont know type of the result.
          // TOP/class --> BOTTOM
          setOperandType(tmpState, dst, Object.class);
        }
      }

      if (dirtied) {
        tmpState.unboxedDirtyVars.add(dst);
      } else {
        // Since the instruction didn't run in unboxed form,
        // dirty unboxed vars will have to get boxed here.
        boxRequiredVars(
            i, tmpState, unboxMap, dst, hasExceptionsRescued(), hitDFBarrier, newInstrs);
      }
    }

    // Add unboxing instrs.
    if (!unboxedLiveVars) {
      for (Variable v : succUnboxedVars.keySet()) {
        if (liveVarsSet.get(lvp.getDFVar(v))) {
          unboxVar(tmpState, succUnboxedVars.get(v), unboxMap, v, newInstrs);
        }
      }
    }

    /*
            System.out.println("------");
            for (Instr i : newInstrs) {
                System.out.println("NEW: " + i);
            }
    */

    basicBlock.replaceInstrs(newInstrs);
  }