view src/share/vm/shark/sharkBlock.cpp @ 1994:6cd6d394f280

7001033: assert(gch->gc_cause() == GCCause::_scavenge_alot || !gch->incremental_collection_failed()) 7002546: regression on SpecJbb2005 on 7b118 comparing to 7b117 on small heaps Summary: Relaxed assertion checking related to incremental_collection_failed flag to allow for ExplicitGCInvokesConcurrent behaviour where we do not want a failing scavenge to bail to a stop-world collection. Parameterized incremental_collection_will_fail() so we can selectively use, or not use, as appropriate, the statistical prediction at specific use sites. This essentially reverts the scavenge bail-out logic to what it was prior to some recent changes that had inadvertently started using the statistical prediction which can be noisy in the presence of bursty loads. Added some associated verbose non-product debugging messages. Reviewed-by: johnc, tonyp
author ysr
date Tue, 07 Dec 2010 21:55:53 -0800
parents f95d63e2154a
children 2cd5e15048e6
line wrap: on
line source

/*
 * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2008, 2009, 2010 Red Hat, Inc.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#include "precompiled.hpp"
#include "interpreter/bytecodes.hpp"
#include "shark/llvmHeaders.hpp"
#include "shark/llvmValue.hpp"
#include "shark/sharkBlock.hpp"
#include "shark/sharkBuilder.hpp"
#include "shark/sharkConstant.hpp"
#include "shark/sharkState.hpp"
#include "shark/sharkValue.hpp"
#include "shark/shark_globals.hpp"
#include "utilities/debug.hpp"

using namespace llvm;

void SharkBlock::parse_bytecode(int start, int limit) {
  SharkValue *a, *b, *c, *d;
  int i;

  // Ensure the current state is initialized before we emit any code,
  // so that any setup code for the state is at the start of the block
  current_state();

  // Parse the bytecodes
  iter()->reset_to_bci(start);
  while (iter()->next_bci() < limit) {
    NOT_PRODUCT(a = b = c = d = NULL);
    iter()->next();

    if (SharkTraceBytecodes)
      tty->print_cr("%4d: %s", bci(), Bytecodes::name(bc()));

    if (has_trap() && trap_bci() == bci()) {
      do_trap(trap_request());
      return;
    }

    if (UseLoopSafepoints) {
      // XXX if a lcmp is followed by an if_?? then C2 maybe-inserts
      // the safepoint before the lcmp rather than before the if.
      // Maybe we should do this too.  See parse2.cpp for details.
      switch (bc()) {
      case Bytecodes::_goto:
      case Bytecodes::_ifnull:
      case Bytecodes::_ifnonnull:
      case Bytecodes::_if_acmpeq:
      case Bytecodes::_if_acmpne:
      case Bytecodes::_ifeq:
      case Bytecodes::_ifne:
      case Bytecodes::_iflt:
      case Bytecodes::_ifle:
      case Bytecodes::_ifgt:
      case Bytecodes::_ifge:
      case Bytecodes::_if_icmpeq:
      case Bytecodes::_if_icmpne:
      case Bytecodes::_if_icmplt:
      case Bytecodes::_if_icmple:
      case Bytecodes::_if_icmpgt:
      case Bytecodes::_if_icmpge:
        if (iter()->get_dest() <= bci())
          maybe_add_backedge_safepoint();
        break;

      case Bytecodes::_goto_w:
        if (iter()->get_far_dest() <= bci())
          maybe_add_backedge_safepoint();
        break;

      case Bytecodes::_tableswitch:
      case Bytecodes::_lookupswitch:
        if (switch_default_dest() <= bci()) {
          maybe_add_backedge_safepoint();
          break;
        }
        int len = switch_table_length();
        for (int i = 0; i < len; i++) {
          if (switch_dest(i) <= bci()) {
            maybe_add_backedge_safepoint();
            break;
          }
        }
        break;
      }
    }

    switch (bc()) {
    case Bytecodes::_nop:
      break;

    case Bytecodes::_aconst_null:
      push(SharkValue::null());
      break;

    case Bytecodes::_iconst_m1:
      push(SharkValue::jint_constant(-1));
      break;
    case Bytecodes::_iconst_0:
      push(SharkValue::jint_constant(0));
      break;
    case Bytecodes::_iconst_1:
      push(SharkValue::jint_constant(1));
      break;
    case Bytecodes::_iconst_2:
      push(SharkValue::jint_constant(2));
      break;
    case Bytecodes::_iconst_3:
      push(SharkValue::jint_constant(3));
      break;
    case Bytecodes::_iconst_4:
      push(SharkValue::jint_constant(4));
      break;
    case Bytecodes::_iconst_5:
      push(SharkValue::jint_constant(5));
      break;

    case Bytecodes::_lconst_0:
      push(SharkValue::jlong_constant(0));
      break;
    case Bytecodes::_lconst_1:
      push(SharkValue::jlong_constant(1));
      break;

    case Bytecodes::_fconst_0:
      push(SharkValue::jfloat_constant(0));
      break;
    case Bytecodes::_fconst_1:
      push(SharkValue::jfloat_constant(1));
      break;
    case Bytecodes::_fconst_2:
      push(SharkValue::jfloat_constant(2));
      break;

    case Bytecodes::_dconst_0:
      push(SharkValue::jdouble_constant(0));
      break;
    case Bytecodes::_dconst_1:
      push(SharkValue::jdouble_constant(1));
      break;

    case Bytecodes::_bipush:
      push(SharkValue::jint_constant(iter()->get_constant_u1()));
      break;
    case Bytecodes::_sipush:
      push(SharkValue::jint_constant(iter()->get_constant_u2()));
      break;

    case Bytecodes::_ldc:
    case Bytecodes::_ldc_w:
    case Bytecodes::_ldc2_w:
      push(SharkConstant::for_ldc(iter())->value(builder()));
      break;

    case Bytecodes::_iload_0:
    case Bytecodes::_lload_0:
    case Bytecodes::_fload_0:
    case Bytecodes::_dload_0:
    case Bytecodes::_aload_0:
      push(local(0));
      break;
    case Bytecodes::_iload_1:
    case Bytecodes::_lload_1:
    case Bytecodes::_fload_1:
    case Bytecodes::_dload_1:
    case Bytecodes::_aload_1:
      push(local(1));
      break;
    case Bytecodes::_iload_2:
    case Bytecodes::_lload_2:
    case Bytecodes::_fload_2:
    case Bytecodes::_dload_2:
    case Bytecodes::_aload_2:
      push(local(2));
      break;
    case Bytecodes::_iload_3:
    case Bytecodes::_lload_3:
    case Bytecodes::_fload_3:
    case Bytecodes::_dload_3:
    case Bytecodes::_aload_3:
      push(local(3));
      break;
    case Bytecodes::_iload:
    case Bytecodes::_lload:
    case Bytecodes::_fload:
    case Bytecodes::_dload:
    case Bytecodes::_aload:
      push(local(iter()->get_index()));
      break;

    case Bytecodes::_baload:
      do_aload(T_BYTE);
      break;
    case Bytecodes::_caload:
      do_aload(T_CHAR);
      break;
    case Bytecodes::_saload:
      do_aload(T_SHORT);
      break;
    case Bytecodes::_iaload:
      do_aload(T_INT);
      break;
    case Bytecodes::_laload:
      do_aload(T_LONG);
      break;
    case Bytecodes::_faload:
      do_aload(T_FLOAT);
      break;
    case Bytecodes::_daload:
      do_aload(T_DOUBLE);
      break;
    case Bytecodes::_aaload:
      do_aload(T_OBJECT);
      break;

    case Bytecodes::_istore_0:
    case Bytecodes::_lstore_0:
    case Bytecodes::_fstore_0:
    case Bytecodes::_dstore_0:
    case Bytecodes::_astore_0:
      set_local(0, pop());
      break;
    case Bytecodes::_istore_1:
    case Bytecodes::_lstore_1:
    case Bytecodes::_fstore_1:
    case Bytecodes::_dstore_1:
    case Bytecodes::_astore_1:
      set_local(1, pop());
      break;
    case Bytecodes::_istore_2:
    case Bytecodes::_lstore_2:
    case Bytecodes::_fstore_2:
    case Bytecodes::_dstore_2:
    case Bytecodes::_astore_2:
      set_local(2, pop());
      break;
    case Bytecodes::_istore_3:
    case Bytecodes::_lstore_3:
    case Bytecodes::_fstore_3:
    case Bytecodes::_dstore_3:
    case Bytecodes::_astore_3:
      set_local(3, pop());
      break;
    case Bytecodes::_istore:
    case Bytecodes::_lstore:
    case Bytecodes::_fstore:
    case Bytecodes::_dstore:
    case Bytecodes::_astore:
      set_local(iter()->get_index(), pop());
      break;

    case Bytecodes::_bastore:
      do_astore(T_BYTE);
      break;
    case Bytecodes::_castore:
      do_astore(T_CHAR);
      break;
    case Bytecodes::_sastore:
      do_astore(T_SHORT);
      break;
    case Bytecodes::_iastore:
      do_astore(T_INT);
      break;
    case Bytecodes::_lastore:
      do_astore(T_LONG);
      break;
    case Bytecodes::_fastore:
      do_astore(T_FLOAT);
      break;
    case Bytecodes::_dastore:
      do_astore(T_DOUBLE);
      break;
    case Bytecodes::_aastore:
      do_astore(T_OBJECT);
      break;

    case Bytecodes::_pop:
      xpop();
      break;
    case Bytecodes::_pop2:
      xpop();
      xpop();
      break;
    case Bytecodes::_swap:
      a = xpop();
      b = xpop();
      xpush(a);
      xpush(b);
      break;
    case Bytecodes::_dup:
      a = xpop();
      xpush(a);
      xpush(a);
      break;
    case Bytecodes::_dup_x1:
      a = xpop();
      b = xpop();
      xpush(a);
      xpush(b);
      xpush(a);
      break;
    case Bytecodes::_dup_x2:
      a = xpop();
      b = xpop();
      c = xpop();
      xpush(a);
      xpush(c);
      xpush(b);
      xpush(a);
      break;
    case Bytecodes::_dup2:
      a = xpop();
      b = xpop();
      xpush(b);
      xpush(a);
      xpush(b);
      xpush(a);
      break;
    case Bytecodes::_dup2_x1:
      a = xpop();
      b = xpop();
      c = xpop();
      xpush(b);
      xpush(a);
      xpush(c);
      xpush(b);
      xpush(a);
      break;
    case Bytecodes::_dup2_x2:
      a = xpop();
      b = xpop();
      c = xpop();
      d = xpop();
      xpush(b);
      xpush(a);
      xpush(d);
      xpush(c);
      xpush(b);
      xpush(a);
      break;

    case Bytecodes::_arraylength:
      do_arraylength();
      break;

    case Bytecodes::_getfield:
      do_getfield();
      break;
    case Bytecodes::_getstatic:
      do_getstatic();
      break;
    case Bytecodes::_putfield:
      do_putfield();
      break;
    case Bytecodes::_putstatic:
      do_putstatic();
      break;

    case Bytecodes::_iadd:
      b = pop();
      a = pop();
      push(SharkValue::create_jint(
        builder()->CreateAdd(a->jint_value(), b->jint_value()), false));
      break;
    case Bytecodes::_isub:
      b = pop();
      a = pop();
      push(SharkValue::create_jint(
        builder()->CreateSub(a->jint_value(), b->jint_value()), false));
      break;
    case Bytecodes::_imul:
      b = pop();
      a = pop();
      push(SharkValue::create_jint(
        builder()->CreateMul(a->jint_value(), b->jint_value()), false));
      break;
    case Bytecodes::_idiv:
      do_idiv();
      break;
    case Bytecodes::_irem:
      do_irem();
      break;
    case Bytecodes::_ineg:
      a = pop();
      push(SharkValue::create_jint(
        builder()->CreateNeg(a->jint_value()), a->zero_checked()));
      break;
    case Bytecodes::_ishl:
      b = pop();
      a = pop();
      push(SharkValue::create_jint(
        builder()->CreateShl(
          a->jint_value(),
          builder()->CreateAnd(
            b->jint_value(), LLVMValue::jint_constant(0x1f))), false));
      break;
    case Bytecodes::_ishr:
      b = pop();
      a = pop();
      push(SharkValue::create_jint(
        builder()->CreateAShr(
          a->jint_value(),
          builder()->CreateAnd(
            b->jint_value(), LLVMValue::jint_constant(0x1f))), false));
      break;
    case Bytecodes::_iushr:
      b = pop();
      a = pop();
      push(SharkValue::create_jint(
        builder()->CreateLShr(
          a->jint_value(),
          builder()->CreateAnd(
            b->jint_value(), LLVMValue::jint_constant(0x1f))), false));
      break;
    case Bytecodes::_iand:
      b = pop();
      a = pop();
      push(SharkValue::create_jint(
        builder()->CreateAnd(a->jint_value(), b->jint_value()), false));
      break;
    case Bytecodes::_ior:
      b = pop();
      a = pop();
      push(SharkValue::create_jint(
        builder()->CreateOr(a->jint_value(), b->jint_value()),
        a->zero_checked() && b->zero_checked()));
      break;
    case Bytecodes::_ixor:
      b = pop();
      a = pop();
      push(SharkValue::create_jint(
        builder()->CreateXor(a->jint_value(), b->jint_value()), false));
      break;

    case Bytecodes::_ladd:
      b = pop();
      a = pop();
      push(SharkValue::create_jlong(
        builder()->CreateAdd(a->jlong_value(), b->jlong_value()), false));
      break;
    case Bytecodes::_lsub:
      b = pop();
      a = pop();
      push(SharkValue::create_jlong(
        builder()->CreateSub(a->jlong_value(), b->jlong_value()), false));
      break;
    case Bytecodes::_lmul:
      b = pop();
      a = pop();
      push(SharkValue::create_jlong(
        builder()->CreateMul(a->jlong_value(), b->jlong_value()), false));
      break;
    case Bytecodes::_ldiv:
      do_ldiv();
      break;
    case Bytecodes::_lrem:
      do_lrem();
      break;
    case Bytecodes::_lneg:
      a = pop();
      push(SharkValue::create_jlong(
        builder()->CreateNeg(a->jlong_value()), a->zero_checked()));
      break;
    case Bytecodes::_lshl:
      b = pop();
      a = pop();
      push(SharkValue::create_jlong(
        builder()->CreateShl(
          a->jlong_value(),
          builder()->CreateIntCast(
            builder()->CreateAnd(
              b->jint_value(), LLVMValue::jint_constant(0x3f)),
            SharkType::jlong_type(), true)), false));
      break;
    case Bytecodes::_lshr:
      b = pop();
      a = pop();
      push(SharkValue::create_jlong(
        builder()->CreateAShr(
          a->jlong_value(),
          builder()->CreateIntCast(
            builder()->CreateAnd(
              b->jint_value(), LLVMValue::jint_constant(0x3f)),
            SharkType::jlong_type(), true)), false));
      break;
    case Bytecodes::_lushr:
      b = pop();
      a = pop();
      push(SharkValue::create_jlong(
        builder()->CreateLShr(
          a->jlong_value(),
          builder()->CreateIntCast(
            builder()->CreateAnd(
              b->jint_value(), LLVMValue::jint_constant(0x3f)),
            SharkType::jlong_type(), true)), false));
      break;
    case Bytecodes::_land:
      b = pop();
      a = pop();
      push(SharkValue::create_jlong(
        builder()->CreateAnd(a->jlong_value(), b->jlong_value()), false));
      break;
    case Bytecodes::_lor:
      b = pop();
      a = pop();
      push(SharkValue::create_jlong(
        builder()->CreateOr(a->jlong_value(), b->jlong_value()),
        a->zero_checked() && b->zero_checked()));
      break;
    case Bytecodes::_lxor:
      b = pop();
      a = pop();
      push(SharkValue::create_jlong(
        builder()->CreateXor(a->jlong_value(), b->jlong_value()), false));
      break;

    case Bytecodes::_fadd:
      b = pop();
      a = pop();
      push(SharkValue::create_jfloat(
        builder()->CreateFAdd(a->jfloat_value(), b->jfloat_value())));
      break;
    case Bytecodes::_fsub:
      b = pop();
      a = pop();
      push(SharkValue::create_jfloat(
        builder()->CreateFSub(a->jfloat_value(), b->jfloat_value())));
      break;
    case Bytecodes::_fmul:
      b = pop();
      a = pop();
      push(SharkValue::create_jfloat(
        builder()->CreateFMul(a->jfloat_value(), b->jfloat_value())));
      break;
    case Bytecodes::_fdiv:
      b = pop();
      a = pop();
      push(SharkValue::create_jfloat(
        builder()->CreateFDiv(a->jfloat_value(), b->jfloat_value())));
      break;
    case Bytecodes::_frem:
      b = pop();
      a = pop();
      push(SharkValue::create_jfloat(
        builder()->CreateFRem(a->jfloat_value(), b->jfloat_value())));
      break;
    case Bytecodes::_fneg:
      a = pop();
      push(SharkValue::create_jfloat(
        builder()->CreateFNeg(a->jfloat_value())));
      break;

    case Bytecodes::_dadd:
      b = pop();
      a = pop();
      push(SharkValue::create_jdouble(
        builder()->CreateFAdd(a->jdouble_value(), b->jdouble_value())));
      break;
    case Bytecodes::_dsub:
      b = pop();
      a = pop();
      push(SharkValue::create_jdouble(
        builder()->CreateFSub(a->jdouble_value(), b->jdouble_value())));
      break;
    case Bytecodes::_dmul:
      b = pop();
      a = pop();
      push(SharkValue::create_jdouble(
        builder()->CreateFMul(a->jdouble_value(), b->jdouble_value())));
      break;
    case Bytecodes::_ddiv:
      b = pop();
      a = pop();
      push(SharkValue::create_jdouble(
        builder()->CreateFDiv(a->jdouble_value(), b->jdouble_value())));
      break;
    case Bytecodes::_drem:
      b = pop();
      a = pop();
      push(SharkValue::create_jdouble(
        builder()->CreateFRem(a->jdouble_value(), b->jdouble_value())));
      break;
    case Bytecodes::_dneg:
      a = pop();
      push(SharkValue::create_jdouble(
        builder()->CreateFNeg(a->jdouble_value())));
      break;

    case Bytecodes::_iinc:
      i = iter()->get_index();
      set_local(
        i,
        SharkValue::create_jint(
          builder()->CreateAdd(
            LLVMValue::jint_constant(iter()->get_iinc_con()),
            local(i)->jint_value()), false));
      break;

    case Bytecodes::_lcmp:
      do_lcmp();
      break;

    case Bytecodes::_fcmpl:
      do_fcmp(false, false);
      break;
    case Bytecodes::_fcmpg:
      do_fcmp(false, true);
      break;
    case Bytecodes::_dcmpl:
      do_fcmp(true, false);
      break;
    case Bytecodes::_dcmpg:
      do_fcmp(true, true);
      break;

    case Bytecodes::_i2l:
      a = pop();
      push(SharkValue::create_jlong(
        builder()->CreateIntCast(
          a->jint_value(), SharkType::jlong_type(), true), a->zero_checked()));
      break;
    case Bytecodes::_i2f:
      push(SharkValue::create_jfloat(
        builder()->CreateSIToFP(
          pop()->jint_value(), SharkType::jfloat_type())));
      break;
    case Bytecodes::_i2d:
      push(SharkValue::create_jdouble(
        builder()->CreateSIToFP(
          pop()->jint_value(), SharkType::jdouble_type())));
      break;

    case Bytecodes::_l2i:
      push(SharkValue::create_jint(
        builder()->CreateIntCast(
          pop()->jlong_value(), SharkType::jint_type(), true), false));
      break;
    case Bytecodes::_l2f:
      push(SharkValue::create_jfloat(
        builder()->CreateSIToFP(
          pop()->jlong_value(), SharkType::jfloat_type())));
      break;
    case Bytecodes::_l2d:
      push(SharkValue::create_jdouble(
        builder()->CreateSIToFP(
          pop()->jlong_value(), SharkType::jdouble_type())));
      break;

    case Bytecodes::_f2i:
      push(SharkValue::create_jint(
        builder()->CreateCall(
          builder()->f2i(), pop()->jfloat_value()), false));
      break;
    case Bytecodes::_f2l:
      push(SharkValue::create_jlong(
        builder()->CreateCall(
          builder()->f2l(), pop()->jfloat_value()), false));
      break;
    case Bytecodes::_f2d:
      push(SharkValue::create_jdouble(
        builder()->CreateFPExt(
          pop()->jfloat_value(), SharkType::jdouble_type())));
      break;

    case Bytecodes::_d2i:
      push(SharkValue::create_jint(
        builder()->CreateCall(
          builder()->d2i(), pop()->jdouble_value()), false));
      break;
    case Bytecodes::_d2l:
      push(SharkValue::create_jlong(
        builder()->CreateCall(
          builder()->d2l(), pop()->jdouble_value()), false));
      break;
    case Bytecodes::_d2f:
      push(SharkValue::create_jfloat(
        builder()->CreateFPTrunc(
          pop()->jdouble_value(), SharkType::jfloat_type())));
      break;

    case Bytecodes::_i2b:
      push(SharkValue::create_jint(
        builder()->CreateAShr(
          builder()->CreateShl(
            pop()->jint_value(),
            LLVMValue::jint_constant(24)),
          LLVMValue::jint_constant(24)), false));
      break;
    case Bytecodes::_i2c:
      push(SharkValue::create_jint(
        builder()->CreateAnd(
            pop()->jint_value(),
            LLVMValue::jint_constant(0xffff)), false));
      break;
    case Bytecodes::_i2s:
      push(SharkValue::create_jint(
        builder()->CreateAShr(
          builder()->CreateShl(
            pop()->jint_value(),
            LLVMValue::jint_constant(16)),
          LLVMValue::jint_constant(16)), false));
      break;

    case Bytecodes::_return:
      do_return(T_VOID);
      break;
    case Bytecodes::_ireturn:
      do_return(T_INT);
      break;
    case Bytecodes::_lreturn:
      do_return(T_LONG);
      break;
    case Bytecodes::_freturn:
      do_return(T_FLOAT);
      break;
    case Bytecodes::_dreturn:
      do_return(T_DOUBLE);
      break;
    case Bytecodes::_areturn:
      do_return(T_OBJECT);
      break;

    case Bytecodes::_athrow:
      do_athrow();
      break;

    case Bytecodes::_goto:
    case Bytecodes::_goto_w:
      do_goto();
      break;

    case Bytecodes::_jsr:
    case Bytecodes::_jsr_w:
      do_jsr();
      break;

    case Bytecodes::_ret:
      do_ret();
      break;

    case Bytecodes::_ifnull:
      do_if(ICmpInst::ICMP_EQ, SharkValue::null(), pop());
      break;
    case Bytecodes::_ifnonnull:
      do_if(ICmpInst::ICMP_NE, SharkValue::null(), pop());
      break;
    case Bytecodes::_if_acmpeq:
      b = pop();
      a = pop();
      do_if(ICmpInst::ICMP_EQ, b, a);
      break;
    case Bytecodes::_if_acmpne:
      b = pop();
      a = pop();
      do_if(ICmpInst::ICMP_NE, b, a);
      break;
    case Bytecodes::_ifeq:
      do_if(ICmpInst::ICMP_EQ, SharkValue::jint_constant(0), pop());
      break;
    case Bytecodes::_ifne:
      do_if(ICmpInst::ICMP_NE, SharkValue::jint_constant(0), pop());
      break;
    case Bytecodes::_iflt:
      do_if(ICmpInst::ICMP_SLT, SharkValue::jint_constant(0), pop());
      break;
    case Bytecodes::_ifle:
      do_if(ICmpInst::ICMP_SLE, SharkValue::jint_constant(0), pop());
      break;
    case Bytecodes::_ifgt:
      do_if(ICmpInst::ICMP_SGT, SharkValue::jint_constant(0), pop());
      break;
    case Bytecodes::_ifge:
      do_if(ICmpInst::ICMP_SGE, SharkValue::jint_constant(0), pop());
      break;
    case Bytecodes::_if_icmpeq:
      b = pop();
      a = pop();
      do_if(ICmpInst::ICMP_EQ, b, a);
      break;
    case Bytecodes::_if_icmpne:
      b = pop();
      a = pop();
      do_if(ICmpInst::ICMP_NE, b, a);
      break;
    case Bytecodes::_if_icmplt:
      b = pop();
      a = pop();
      do_if(ICmpInst::ICMP_SLT, b, a);
      break;
    case Bytecodes::_if_icmple:
      b = pop();
      a = pop();
      do_if(ICmpInst::ICMP_SLE, b, a);
      break;
    case Bytecodes::_if_icmpgt:
      b = pop();
      a = pop();
      do_if(ICmpInst::ICMP_SGT, b, a);
      break;
    case Bytecodes::_if_icmpge:
      b = pop();
      a = pop();
      do_if(ICmpInst::ICMP_SGE, b, a);
      break;

    case Bytecodes::_tableswitch:
    case Bytecodes::_lookupswitch:
      do_switch();
      break;

    case Bytecodes::_invokestatic:
    case Bytecodes::_invokespecial:
    case Bytecodes::_invokevirtual:
    case Bytecodes::_invokeinterface:
      do_call();
      break;

    case Bytecodes::_instanceof:
      // This is a very common construct:
      //
      //  if (object instanceof Klass) {
      //    something = (Klass) object;
      //    ...
      //  }
      //
      // which gets compiled to something like this:
      //
      //  28: aload 9
      //  30: instanceof <Class Klass>
      //  33: ifeq 52
      //  36: aload 9
      //  38: checkcast <Class Klass>
      //
      // Handling both bytecodes at once allows us
      // to eliminate the checkcast.
      if (iter()->next_bci() < limit &&
          (iter()->next_bc() == Bytecodes::_ifeq ||
           iter()->next_bc() == Bytecodes::_ifne) &&
          (!UseLoopSafepoints ||
           iter()->next_get_dest() > iter()->next_bci())) {
        if (maybe_do_instanceof_if()) {
          iter()->next();
          if (SharkTraceBytecodes)
            tty->print_cr("%4d: %s", bci(), Bytecodes::name(bc()));
          break;
        }
      }
      // fall through
    case Bytecodes::_checkcast:
      do_instance_check();
      break;

    case Bytecodes::_new:
      do_new();
      break;
    case Bytecodes::_newarray:
      do_newarray();
      break;
    case Bytecodes::_anewarray:
      do_anewarray();
      break;
    case Bytecodes::_multianewarray:
      do_multianewarray();
      break;

    case Bytecodes::_monitorenter:
      do_monitorenter();
      break;
    case Bytecodes::_monitorexit:
      do_monitorexit();
      break;

    default:
      ShouldNotReachHere();
    }
  }
}

SharkState* SharkBlock::initial_current_state() {
  return entry_state()->copy();
}

int SharkBlock::switch_default_dest() {
  return iter()->get_dest_table(0);
}

int SharkBlock::switch_table_length() {
  switch(bc()) {
  case Bytecodes::_tableswitch:
    return iter()->get_int_table(2) - iter()->get_int_table(1) + 1;

  case Bytecodes::_lookupswitch:
    return iter()->get_int_table(1);

  default:
    ShouldNotReachHere();
  }
}

int SharkBlock::switch_key(int i) {
  switch(bc()) {
  case Bytecodes::_tableswitch:
    return iter()->get_int_table(1) + i;

  case Bytecodes::_lookupswitch:
    return iter()->get_int_table(2 + 2 * i);

  default:
    ShouldNotReachHere();
  }
}

int SharkBlock::switch_dest(int i) {
  switch(bc()) {
  case Bytecodes::_tableswitch:
    return iter()->get_dest_table(i + 3);

  case Bytecodes::_lookupswitch:
    return iter()->get_dest_table(2 + 2 * i + 1);

  default:
    ShouldNotReachHere();
  }
}

void SharkBlock::do_div_or_rem(bool is_long, bool is_rem) {
  SharkValue *sb = pop();
  SharkValue *sa = pop();

  check_divide_by_zero(sb);

  Value *a, *b, *p, *q;
  if (is_long) {
    a = sa->jlong_value();
    b = sb->jlong_value();
    p = LLVMValue::jlong_constant(0x8000000000000000LL);
    q = LLVMValue::jlong_constant(-1);
  }
  else {
    a = sa->jint_value();
    b = sb->jint_value();
    p = LLVMValue::jint_constant(0x80000000);
    q = LLVMValue::jint_constant(-1);
  }

  BasicBlock *ip           = builder()->GetBlockInsertionPoint();
  BasicBlock *special_case = builder()->CreateBlock(ip, "special_case");
  BasicBlock *general_case = builder()->CreateBlock(ip, "general_case");
  BasicBlock *done         = builder()->CreateBlock(ip, "done");

  builder()->CreateCondBr(
    builder()->CreateAnd(
      builder()->CreateICmpEQ(a, p),
      builder()->CreateICmpEQ(b, q)),
    special_case, general_case);

  builder()->SetInsertPoint(special_case);
  Value *special_result;
  if (is_rem) {
    if (is_long)
      special_result = LLVMValue::jlong_constant(0);
    else
      special_result = LLVMValue::jint_constant(0);
  }
  else {
    special_result = a;
  }
  builder()->CreateBr(done);

  builder()->SetInsertPoint(general_case);
  Value *general_result;
  if (is_rem)
    general_result = builder()->CreateSRem(a, b);
  else
    general_result = builder()->CreateSDiv(a, b);
  builder()->CreateBr(done);

  builder()->SetInsertPoint(done);
  PHINode *result;
  if (is_long)
    result = builder()->CreatePHI(SharkType::jlong_type(), "result");
  else
    result = builder()->CreatePHI(SharkType::jint_type(), "result");
  result->addIncoming(special_result, special_case);
  result->addIncoming(general_result, general_case);

  if (is_long)
    push(SharkValue::create_jlong(result, false));
  else
    push(SharkValue::create_jint(result, false));
}

void SharkBlock::do_field_access(bool is_get, bool is_field) {
  bool will_link;
  ciField *field = iter()->get_field(will_link);
  assert(will_link, "typeflow responsibility");
  assert(is_field != field->is_static(), "mismatch");

  // Pop the value off the stack where necessary
  SharkValue *value = NULL;
  if (!is_get)
    value = pop();

  // Find the object we're accessing, if necessary
  Value *object = NULL;
  if (is_field) {
    SharkValue *value = pop();
    check_null(value);
    object = value->generic_value();
  }
  if (is_get && field->is_constant()) {
    SharkConstant *constant = SharkConstant::for_field(iter());
    if (constant->is_loaded())
      value = constant->value(builder());
  }
  if (!is_get || value == NULL) {
    if (!is_field)
      object = builder()->CreateInlineOop(field->holder());

    BasicType   basic_type = field->type()->basic_type();
    const Type *stack_type = SharkType::to_stackType(basic_type);
    const Type *field_type = SharkType::to_arrayType(basic_type);

    Value *addr = builder()->CreateAddressOfStructEntry(
      object, in_ByteSize(field->offset_in_bytes()),
      PointerType::getUnqual(field_type),
      "addr");

    // Do the access
    if (is_get) {
      Value *field_value = builder()->CreateLoad(addr);

      if (field_type != stack_type) {
        field_value = builder()->CreateIntCast(
          field_value, stack_type, basic_type != T_CHAR);
      }

      value = SharkValue::create_generic(field->type(), field_value, false);
    }
    else {
      Value *field_value = value->generic_value();

      if (field_type != stack_type) {
        field_value = builder()->CreateIntCast(
          field_value, field_type, basic_type != T_CHAR);
      }

      builder()->CreateStore(field_value, addr);

      if (!field->type()->is_primitive_type())
        builder()->CreateUpdateBarrierSet(oopDesc::bs(), addr);

      if (field->is_volatile())
        builder()->CreateMemoryBarrier(SharkBuilder::BARRIER_STORELOAD);
    }
  }

  // Push the value onto the stack where necessary
  if (is_get)
    push(value);
}

void SharkBlock::do_lcmp() {
  Value *b = pop()->jlong_value();
  Value *a = pop()->jlong_value();

  BasicBlock *ip   = builder()->GetBlockInsertionPoint();
  BasicBlock *ne   = builder()->CreateBlock(ip, "lcmp_ne");
  BasicBlock *lt   = builder()->CreateBlock(ip, "lcmp_lt");
  BasicBlock *gt   = builder()->CreateBlock(ip, "lcmp_gt");
  BasicBlock *done = builder()->CreateBlock(ip, "done");

  BasicBlock *eq = builder()->GetInsertBlock();
  builder()->CreateCondBr(builder()->CreateICmpEQ(a, b), done, ne);

  builder()->SetInsertPoint(ne);
  builder()->CreateCondBr(builder()->CreateICmpSLT(a, b), lt, gt);

  builder()->SetInsertPoint(lt);
  builder()->CreateBr(done);

  builder()->SetInsertPoint(gt);
  builder()->CreateBr(done);

  builder()->SetInsertPoint(done);
  PHINode *result = builder()->CreatePHI(SharkType::jint_type(), "result");
  result->addIncoming(LLVMValue::jint_constant(-1), lt);
  result->addIncoming(LLVMValue::jint_constant(0),  eq);
  result->addIncoming(LLVMValue::jint_constant(1),  gt);

  push(SharkValue::create_jint(result, false));
}

void SharkBlock::do_fcmp(bool is_double, bool unordered_is_greater) {
  Value *a, *b;
  if (is_double) {
    b = pop()->jdouble_value();
    a = pop()->jdouble_value();
  }
  else {
    b = pop()->jfloat_value();
    a = pop()->jfloat_value();
  }

  BasicBlock *ip      = builder()->GetBlockInsertionPoint();
  BasicBlock *ordered = builder()->CreateBlock(ip, "ordered");
  BasicBlock *ge      = builder()->CreateBlock(ip, "fcmp_ge");
  BasicBlock *lt      = builder()->CreateBlock(ip, "fcmp_lt");
  BasicBlock *eq      = builder()->CreateBlock(ip, "fcmp_eq");
  BasicBlock *gt      = builder()->CreateBlock(ip, "fcmp_gt");
  BasicBlock *done    = builder()->CreateBlock(ip, "done");

  builder()->CreateCondBr(
    builder()->CreateFCmpUNO(a, b),
    unordered_is_greater ? gt : lt, ordered);

  builder()->SetInsertPoint(ordered);
  builder()->CreateCondBr(builder()->CreateFCmpULT(a, b), lt, ge);

  builder()->SetInsertPoint(ge);
  builder()->CreateCondBr(builder()->CreateFCmpUGT(a, b), gt, eq);

  builder()->SetInsertPoint(lt);
  builder()->CreateBr(done);

  builder()->SetInsertPoint(gt);
  builder()->CreateBr(done);

  builder()->SetInsertPoint(eq);
  builder()->CreateBr(done);

  builder()->SetInsertPoint(done);
  PHINode *result = builder()->CreatePHI(SharkType::jint_type(), "result");
  result->addIncoming(LLVMValue::jint_constant(-1), lt);
  result->addIncoming(LLVMValue::jint_constant(0),  eq);
  result->addIncoming(LLVMValue::jint_constant(1),  gt);

  push(SharkValue::create_jint(result, false));
}

void SharkBlock::emit_IR() {
  ShouldNotCallThis();
}

SharkState* SharkBlock::entry_state() {
  ShouldNotCallThis();
}

void SharkBlock::do_zero_check(SharkValue* value) {
  ShouldNotCallThis();
}

void SharkBlock::maybe_add_backedge_safepoint() {
  ShouldNotCallThis();
}

bool SharkBlock::has_trap() {
  return false;
}

int SharkBlock::trap_request() {
  ShouldNotCallThis();
}

int SharkBlock::trap_bci() {
  ShouldNotCallThis();
}

void SharkBlock::do_trap(int trap_request) {
  ShouldNotCallThis();
}

void SharkBlock::do_arraylength() {
  ShouldNotCallThis();
}

void SharkBlock::do_aload(BasicType basic_type) {
  ShouldNotCallThis();
}

void SharkBlock::do_astore(BasicType basic_type) {
  ShouldNotCallThis();
}

void SharkBlock::do_return(BasicType type) {
  ShouldNotCallThis();
}

void SharkBlock::do_athrow() {
  ShouldNotCallThis();
}

void SharkBlock::do_goto() {
  ShouldNotCallThis();
}

void SharkBlock::do_jsr() {
  ShouldNotCallThis();
}

void SharkBlock::do_ret() {
  ShouldNotCallThis();
}

void SharkBlock::do_if(ICmpInst::Predicate p, SharkValue* b, SharkValue* a) {
  ShouldNotCallThis();
}

void SharkBlock::do_switch() {
  ShouldNotCallThis();
}

void SharkBlock::do_call() {
  ShouldNotCallThis();
}

void SharkBlock::do_instance_check() {
  ShouldNotCallThis();
}

bool SharkBlock::maybe_do_instanceof_if() {
  ShouldNotCallThis();
}

void SharkBlock::do_new() {
  ShouldNotCallThis();
}

void SharkBlock::do_newarray() {
  ShouldNotCallThis();
}

void SharkBlock::do_anewarray() {
  ShouldNotCallThis();
}

void SharkBlock::do_multianewarray() {
  ShouldNotCallThis();
}

void SharkBlock::do_monitorenter() {
  ShouldNotCallThis();
}

void SharkBlock::do_monitorexit() {
  ShouldNotCallThis();
}