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comparison src/share/vm/opto/parse2.cpp @ 276:aa8f54688692

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Merge
author trims
date Sun, 10 Aug 2008 21:31:42 -0700
parents 3e333d6f35dd
children 8261ee795323
comparison
equal deleted inserted replaced
240:585535ec8a14 276:aa8f54688692
873 // counts would keep the program recompiling indefinitely. 873 // counts would keep the program recompiling indefinitely.
874 bool Parse::seems_never_taken(float prob) { 874 bool Parse::seems_never_taken(float prob) {
875 return prob < PROB_MIN; 875 return prob < PROB_MIN;
876 } 876 }
877 877
878 //-------------------------------repush_if_args--------------------------------
879 // Push arguments of an "if" bytecode back onto the stack by adjusting _sp.
878 inline void Parse::repush_if_args() { 880 inline void Parse::repush_if_args() {
879 #ifndef PRODUCT 881 #ifndef PRODUCT
880 if (PrintOpto && WizardMode) { 882 if (PrintOpto && WizardMode) {
881 tty->print("defending against excessive implicit null exceptions on %s @%d in ", 883 tty->print("defending against excessive implicit null exceptions on %s @%d in ",
882 Bytecodes::name(iter().cur_bc()), iter().cur_bci()); 884 Bytecodes::name(iter().cur_bc()), iter().cur_bci());
890 assert(bc_depth == 1 || argument(1) != NULL, "two must exist"); 892 assert(bc_depth == 1 || argument(1) != NULL, "two must exist");
891 _sp += bc_depth; 893 _sp += bc_depth;
892 } 894 }
893 895
894 //----------------------------------do_ifnull---------------------------------- 896 //----------------------------------do_ifnull----------------------------------
895 void Parse::do_ifnull(BoolTest::mask btest) { 897 void Parse::do_ifnull(BoolTest::mask btest, Node *c) {
896 int target_bci = iter().get_dest(); 898 int target_bci = iter().get_dest();
897 899
898 Block* branch_block = successor_for_bci(target_bci); 900 Block* branch_block = successor_for_bci(target_bci);
899 Block* next_block = successor_for_bci(iter().next_bci()); 901 Block* next_block = successor_for_bci(iter().next_bci());
900 902
902 float prob = branch_prediction(cnt, btest, target_bci); 904 float prob = branch_prediction(cnt, btest, target_bci);
903 if (prob == PROB_UNKNOWN) { 905 if (prob == PROB_UNKNOWN) {
904 // (An earlier version of do_ifnull omitted this trap for OSR methods.) 906 // (An earlier version of do_ifnull omitted this trap for OSR methods.)
905 #ifndef PRODUCT 907 #ifndef PRODUCT
906 if (PrintOpto && Verbose) 908 if (PrintOpto && Verbose)
907 tty->print_cr("Never-taken backedge stops compilation at bci %d",bci()); 909 tty->print_cr("Never-taken edge stops compilation at bci %d",bci());
908 #endif 910 #endif
909 repush_if_args(); // to gather stats on loop 911 repush_if_args(); // to gather stats on loop
910 // We need to mark this branch as taken so that if we recompile we will 912 // We need to mark this branch as taken so that if we recompile we will
911 // see that it is possible. In the tiered system the interpreter doesn't 913 // see that it is possible. In the tiered system the interpreter doesn't
912 // do profiling and by the time we get to the lower tier from the interpreter 914 // do profiling and by the time we get to the lower tier from the interpreter
921 next_block->next_path_num(); 923 next_block->next_path_num();
922 } 924 }
923 return; 925 return;
924 } 926 }
925 927
926 // If this is a backwards branch in the bytecodes, add Safepoint
927 maybe_add_safepoint(target_bci);
928
929 explicit_null_checks_inserted++; 928 explicit_null_checks_inserted++;
930 Node* a = null();
931 Node* b = pop();
932 Node* c = _gvn.transform( new (C, 3) CmpPNode(b, a) );
933
934 // Make a cast-away-nullness that is control dependent on the test
935 const Type *t = _gvn.type(b);
936 const Type *t_not_null = t->join(TypePtr::NOTNULL);
937 Node *cast = new (C, 2) CastPPNode(b,t_not_null);
938 929
939 // Generate real control flow 930 // Generate real control flow
940 Node *tst = _gvn.transform( new (C, 2) BoolNode( c, btest ) ); 931 Node *tst = _gvn.transform( new (C, 2) BoolNode( c, btest ) );
941 932
942 // Sanity check the probability value 933 // Sanity check the probability value
994 float untaken_prob = 1.0 - prob; 985 float untaken_prob = 1.0 - prob;
995 986
996 if (prob == PROB_UNKNOWN) { 987 if (prob == PROB_UNKNOWN) {
997 #ifndef PRODUCT 988 #ifndef PRODUCT
998 if (PrintOpto && Verbose) 989 if (PrintOpto && Verbose)
999 tty->print_cr("Never-taken backedge stops compilation at bci %d",bci()); 990 tty->print_cr("Never-taken edge stops compilation at bci %d",bci());
1000 #endif 991 #endif
1001 repush_if_args(); // to gather stats on loop 992 repush_if_args(); // to gather stats on loop
1002 // We need to mark this branch as taken so that if we recompile we will 993 // We need to mark this branch as taken so that if we recompile we will
1003 // see that it is possible. In the tiered system the interpreter doesn't 994 // see that it is possible. In the tiered system the interpreter doesn't
1004 // do profiling and by the time we get to the lower tier from the interpreter 995 // do profiling and by the time we get to the lower tier from the interpreter
2098 taken = method()->scale_count(taken); 2089 taken = method()->scale_count(taken);
2099 target_block->set_count(taken); 2090 target_block->set_count(taken);
2100 break; 2091 break;
2101 } 2092 }
2102 2093
2103 case Bytecodes::_ifnull: 2094 case Bytecodes::_ifnull: btest = BoolTest::eq; goto handle_if_null;
2104 do_ifnull(BoolTest::eq); 2095 case Bytecodes::_ifnonnull: btest = BoolTest::ne; goto handle_if_null;
2105 break; 2096 handle_if_null:
2106 case Bytecodes::_ifnonnull: 2097 // If this is a backwards branch in the bytecodes, add Safepoint
2107 do_ifnull(BoolTest::ne); 2098 maybe_add_safepoint(iter().get_dest());
2099 a = null();
2100 b = pop();
2101 c = _gvn.transform( new (C, 3) CmpPNode(b, a) );
2102 do_ifnull(btest, c);
2108 break; 2103 break;
2109 2104
2110 case Bytecodes::_if_acmpeq: btest = BoolTest::eq; goto handle_if_acmp; 2105 case Bytecodes::_if_acmpeq: btest = BoolTest::eq; goto handle_if_acmp;
2111 case Bytecodes::_if_acmpne: btest = BoolTest::ne; goto handle_if_acmp; 2106 case Bytecodes::_if_acmpne: btest = BoolTest::ne; goto handle_if_acmp;
2112 handle_if_acmp: 2107 handle_if_acmp: