Mercurial > hg > graal-jvmci-8
comparison src/share/vm/opto/graphKit.cpp @ 12966:b2ee5dc63353
8024070: C2 needs some form of type speculation
Summary: record unused type profile information with type system, propagate and use it.
Reviewed-by: kvn, twisti
author | roland |
---|---|
date | Wed, 23 Oct 2013 12:40:23 +0200 |
parents | 3213ba4d3dff |
children | 096c224171c4 de6a9e811145 2113136690bc |
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12965:8b4bbba322d3 | 12966:b2ee5dc63353 |
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2096 set_argument(j, arg); | 2096 set_argument(j, arg); |
2097 } | 2097 } |
2098 } | 2098 } |
2099 } | 2099 } |
2100 | 2100 |
2101 /** | |
2102 * Record profiling data exact_kls for Node n with the type system so | |
2103 * that it can propagate it (speculation) | |
2104 * | |
2105 * @param n node that the type applies to | |
2106 * @param exact_kls type from profiling | |
2107 * | |
2108 * @return node with improved type | |
2109 */ | |
2110 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls) { | |
2111 const TypeOopPtr* current_type = _gvn.type(n)->isa_oopptr(); | |
2112 assert(UseTypeSpeculation, "type speculation must be on"); | |
2113 if (exact_kls != NULL && | |
2114 // nothing to improve if type is already exact | |
2115 (current_type == NULL || | |
2116 (!current_type->klass_is_exact() && | |
2117 (current_type->speculative() == NULL || | |
2118 !current_type->speculative()->klass_is_exact())))) { | |
2119 const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls); | |
2120 const TypeOopPtr* xtype = tklass->as_instance_type(); | |
2121 assert(xtype->klass_is_exact(), "Should be exact"); | |
2122 | |
2123 // Build a type with a speculative type (what we think we know | |
2124 // about the type but will need a guard when we use it) | |
2125 const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, xtype); | |
2126 // We're changing the type, we need a new cast node to carry the | |
2127 // new type. The new type depends on the control: what profiling | |
2128 // tells us is only valid from here as far as we can tell. | |
2129 Node* cast = new(C) CastPPNode(n, spec_type); | |
2130 cast->init_req(0, control()); | |
2131 cast = _gvn.transform(cast); | |
2132 replace_in_map(n, cast); | |
2133 n = cast; | |
2134 } | |
2135 return n; | |
2136 } | |
2137 | |
2138 /** | |
2139 * Record profiling data from receiver profiling at an invoke with the | |
2140 * type system so that it can propagate it (speculation) | |
2141 * | |
2142 * @param n receiver node | |
2143 * | |
2144 * @return node with improved type | |
2145 */ | |
2146 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) { | |
2147 if (!UseTypeSpeculation) { | |
2148 return n; | |
2149 } | |
2150 ciKlass* exact_kls = profile_has_unique_klass(); | |
2151 return record_profile_for_speculation(n, exact_kls); | |
2152 } | |
2153 | |
2154 /** | |
2155 * Record profiling data from argument profiling at an invoke with the | |
2156 * type system so that it can propagate it (speculation) | |
2157 * | |
2158 * @param dest_method target method for the call | |
2159 * @param bc what invoke bytecode is this? | |
2160 */ | |
2161 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) { | |
2162 if (!UseTypeSpeculation) { | |
2163 return; | |
2164 } | |
2165 const TypeFunc* tf = TypeFunc::make(dest_method); | |
2166 int nargs = tf->_domain->_cnt - TypeFunc::Parms; | |
2167 int skip = Bytecodes::has_receiver(bc) ? 1 : 0; | |
2168 for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) { | |
2169 const Type *targ = tf->_domain->field_at(j + TypeFunc::Parms); | |
2170 if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) { | |
2171 ciKlass* better_type = method()->argument_profiled_type(bci(), i); | |
2172 if (better_type != NULL) { | |
2173 record_profile_for_speculation(argument(j), better_type); | |
2174 } | |
2175 i++; | |
2176 } | |
2177 } | |
2178 } | |
2179 | |
2180 /** | |
2181 * Record profiling data from parameter profiling at an invoke with | |
2182 * the type system so that it can propagate it (speculation) | |
2183 */ | |
2184 void GraphKit::record_profiled_parameters_for_speculation() { | |
2185 if (!UseTypeSpeculation) { | |
2186 return; | |
2187 } | |
2188 for (int i = 0, j = 0; i < method()->arg_size() ; i++) { | |
2189 if (_gvn.type(local(i))->isa_oopptr()) { | |
2190 ciKlass* better_type = method()->parameter_profiled_type(j); | |
2191 if (better_type != NULL) { | |
2192 record_profile_for_speculation(local(i), better_type); | |
2193 } | |
2194 j++; | |
2195 } | |
2196 } | |
2197 } | |
2198 | |
2101 void GraphKit::round_double_result(ciMethod* dest_method) { | 2199 void GraphKit::round_double_result(ciMethod* dest_method) { |
2102 // A non-strict method may return a double value which has an extended | 2200 // A non-strict method may return a double value which has an extended |
2103 // exponent, but this must not be visible in a caller which is 'strict' | 2201 // exponent, but this must not be visible in a caller which is 'strict' |
2104 // If a strict caller invokes a non-strict callee, round a double result | 2202 // If a strict caller invokes a non-strict callee, round a double result |
2105 | 2203 |
2633 | 2731 |
2634 //------------------------maybe_cast_profiled_receiver------------------------- | 2732 //------------------------maybe_cast_profiled_receiver------------------------- |
2635 // If the profile has seen exactly one type, narrow to exactly that type. | 2733 // If the profile has seen exactly one type, narrow to exactly that type. |
2636 // Subsequent type checks will always fold up. | 2734 // Subsequent type checks will always fold up. |
2637 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj, | 2735 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj, |
2638 ciProfileData* data, | 2736 ciKlass* require_klass, |
2639 ciKlass* require_klass) { | 2737 ciKlass* spec_klass, |
2738 bool safe_for_replace) { | |
2640 if (!UseTypeProfile || !TypeProfileCasts) return NULL; | 2739 if (!UseTypeProfile || !TypeProfileCasts) return NULL; |
2641 if (data == NULL) return NULL; | |
2642 | 2740 |
2643 // Make sure we haven't already deoptimized from this tactic. | 2741 // Make sure we haven't already deoptimized from this tactic. |
2644 if (too_many_traps(Deoptimization::Reason_class_check)) | 2742 if (too_many_traps(Deoptimization::Reason_class_check)) |
2645 return NULL; | 2743 return NULL; |
2646 | 2744 |
2647 // (No, this isn't a call, but it's enough like a virtual call | 2745 // (No, this isn't a call, but it's enough like a virtual call |
2648 // to use the same ciMethod accessor to get the profile info...) | 2746 // to use the same ciMethod accessor to get the profile info...) |
2649 ciCallProfile profile = method()->call_profile_at_bci(bci()); | 2747 // If we have a speculative type use it instead of profiling (which |
2650 if (profile.count() >= 0 && // no cast failures here | 2748 // may not help us) |
2651 profile.has_receiver(0) && | 2749 ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass; |
2652 profile.morphism() == 1) { | 2750 if (exact_kls != NULL) {// no cast failures here |
2653 ciKlass* exact_kls = profile.receiver(0); | |
2654 if (require_klass == NULL || | 2751 if (require_klass == NULL || |
2655 static_subtype_check(require_klass, exact_kls) == SSC_always_true) { | 2752 static_subtype_check(require_klass, exact_kls) == SSC_always_true) { |
2656 // If we narrow the type to match what the type profile sees, | 2753 // If we narrow the type to match what the type profile sees or |
2657 // we can then remove the rest of the cast. | 2754 // the speculative type, we can then remove the rest of the |
2755 // cast. | |
2658 // This is a win, even if the exact_kls is very specific, | 2756 // This is a win, even if the exact_kls is very specific, |
2659 // because downstream operations, such as method calls, | 2757 // because downstream operations, such as method calls, |
2660 // will often benefit from the sharper type. | 2758 // will often benefit from the sharper type. |
2661 Node* exact_obj = not_null_obj; // will get updated in place... | 2759 Node* exact_obj = not_null_obj; // will get updated in place... |
2662 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0, | 2760 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0, |
2664 { PreserveJVMState pjvms(this); | 2762 { PreserveJVMState pjvms(this); |
2665 set_control(slow_ctl); | 2763 set_control(slow_ctl); |
2666 uncommon_trap(Deoptimization::Reason_class_check, | 2764 uncommon_trap(Deoptimization::Reason_class_check, |
2667 Deoptimization::Action_maybe_recompile); | 2765 Deoptimization::Action_maybe_recompile); |
2668 } | 2766 } |
2767 if (safe_for_replace) { | |
2768 replace_in_map(not_null_obj, exact_obj); | |
2769 } | |
2770 return exact_obj; | |
2771 } | |
2772 // assert(ssc == SSC_always_true)... except maybe the profile lied to us. | |
2773 } | |
2774 | |
2775 return NULL; | |
2776 } | |
2777 | |
2778 /** | |
2779 * Cast obj to type and emit guard unless we had too many traps here | |
2780 * already | |
2781 * | |
2782 * @param obj node being casted | |
2783 * @param type type to cast the node to | |
2784 * @param not_null true if we know node cannot be null | |
2785 */ | |
2786 Node* GraphKit::maybe_cast_profiled_obj(Node* obj, | |
2787 ciKlass* type, | |
2788 bool not_null) { | |
2789 // type == NULL if profiling tells us this object is always null | |
2790 if (type != NULL) { | |
2791 if (!too_many_traps(Deoptimization::Reason_null_check) && | |
2792 !too_many_traps(Deoptimization::Reason_class_check)) { | |
2793 Node* not_null_obj = NULL; | |
2794 // not_null is true if we know the object is not null and | |
2795 // there's no need for a null check | |
2796 if (!not_null) { | |
2797 Node* null_ctl = top(); | |
2798 not_null_obj = null_check_oop(obj, &null_ctl, true, true); | |
2799 assert(null_ctl->is_top(), "no null control here"); | |
2800 } else { | |
2801 not_null_obj = obj; | |
2802 } | |
2803 | |
2804 Node* exact_obj = not_null_obj; | |
2805 ciKlass* exact_kls = type; | |
2806 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0, | |
2807 &exact_obj); | |
2808 { | |
2809 PreserveJVMState pjvms(this); | |
2810 set_control(slow_ctl); | |
2811 uncommon_trap(Deoptimization::Reason_class_check, | |
2812 Deoptimization::Action_maybe_recompile); | |
2813 } | |
2669 replace_in_map(not_null_obj, exact_obj); | 2814 replace_in_map(not_null_obj, exact_obj); |
2670 return exact_obj; | 2815 obj = exact_obj; |
2671 } | 2816 } |
2672 // assert(ssc == SSC_always_true)... except maybe the profile lied to us. | 2817 } else { |
2673 } | 2818 if (!too_many_traps(Deoptimization::Reason_null_assert)) { |
2674 | 2819 Node* exact_obj = null_assert(obj); |
2675 return NULL; | 2820 replace_in_map(obj, exact_obj); |
2676 } | 2821 obj = exact_obj; |
2677 | 2822 } |
2823 } | |
2824 return obj; | |
2825 } | |
2678 | 2826 |
2679 //-------------------------------gen_instanceof-------------------------------- | 2827 //-------------------------------gen_instanceof-------------------------------- |
2680 // Generate an instance-of idiom. Used by both the instance-of bytecode | 2828 // Generate an instance-of idiom. Used by both the instance-of bytecode |
2681 // and the reflective instance-of call. | 2829 // and the reflective instance-of call. |
2682 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass) { | 2830 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) { |
2683 kill_dead_locals(); // Benefit all the uncommon traps | 2831 kill_dead_locals(); // Benefit all the uncommon traps |
2684 assert( !stopped(), "dead parse path should be checked in callers" ); | 2832 assert( !stopped(), "dead parse path should be checked in callers" ); |
2685 assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()), | 2833 assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()), |
2686 "must check for not-null not-dead klass in callers"); | 2834 "must check for not-null not-dead klass in callers"); |
2687 | 2835 |
2690 RegionNode* region = new(C) RegionNode(PATH_LIMIT); | 2838 RegionNode* region = new(C) RegionNode(PATH_LIMIT); |
2691 Node* phi = new(C) PhiNode(region, TypeInt::BOOL); | 2839 Node* phi = new(C) PhiNode(region, TypeInt::BOOL); |
2692 C->set_has_split_ifs(true); // Has chance for split-if optimization | 2840 C->set_has_split_ifs(true); // Has chance for split-if optimization |
2693 | 2841 |
2694 ciProfileData* data = NULL; | 2842 ciProfileData* data = NULL; |
2695 bool safe_for_replace = false; | |
2696 if (java_bc() == Bytecodes::_instanceof) { // Only for the bytecode | 2843 if (java_bc() == Bytecodes::_instanceof) { // Only for the bytecode |
2697 data = method()->method_data()->bci_to_data(bci()); | 2844 data = method()->method_data()->bci_to_data(bci()); |
2698 safe_for_replace = true; | |
2699 } | 2845 } |
2700 bool never_see_null = (ProfileDynamicTypes // aggressive use of profile | 2846 bool never_see_null = (ProfileDynamicTypes // aggressive use of profile |
2701 && seems_never_null(obj, data)); | 2847 && seems_never_null(obj, data)); |
2702 | 2848 |
2703 // Null check; get casted pointer; set region slot 3 | 2849 // Null check; get casted pointer; set region slot 3 |
2717 assert(_null_path == PATH_LIMIT-1, "delete last"); | 2863 assert(_null_path == PATH_LIMIT-1, "delete last"); |
2718 region->del_req(_null_path); | 2864 region->del_req(_null_path); |
2719 phi ->del_req(_null_path); | 2865 phi ->del_req(_null_path); |
2720 } | 2866 } |
2721 | 2867 |
2722 if (ProfileDynamicTypes && data != NULL) { | 2868 // Do we know the type check always succeed? |
2723 Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, data, NULL); | 2869 bool known_statically = false; |
2724 if (stopped()) { // Profile disagrees with this path. | 2870 if (_gvn.type(superklass)->singleton()) { |
2725 set_control(null_ctl); // Null is the only remaining possibility. | 2871 ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass(); |
2726 return intcon(0); | 2872 ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass(); |
2727 } | 2873 if (subk != NULL && subk->is_loaded()) { |
2728 if (cast_obj != NULL) | 2874 int static_res = static_subtype_check(superk, subk); |
2729 not_null_obj = cast_obj; | 2875 known_statically = (static_res == SSC_always_true || static_res == SSC_always_false); |
2876 } | |
2877 } | |
2878 | |
2879 if (known_statically && UseTypeSpeculation) { | |
2880 // If we know the type check always succeed then we don't use the | |
2881 // profiling data at this bytecode. Don't lose it, feed it to the | |
2882 // type system as a speculative type. | |
2883 not_null_obj = record_profiled_receiver_for_speculation(not_null_obj); | |
2884 } else { | |
2885 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr(); | |
2886 // We may not have profiling here or it may not help us. If we | |
2887 // have a speculative type use it to perform an exact cast. | |
2888 ciKlass* spec_obj_type = obj_type->speculative_type(); | |
2889 if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) { | |
2890 Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace); | |
2891 if (stopped()) { // Profile disagrees with this path. | |
2892 set_control(null_ctl); // Null is the only remaining possibility. | |
2893 return intcon(0); | |
2894 } | |
2895 if (cast_obj != NULL) { | |
2896 not_null_obj = cast_obj; | |
2897 } | |
2898 } | |
2730 } | 2899 } |
2731 | 2900 |
2732 // Load the object's klass | 2901 // Load the object's klass |
2733 Node* obj_klass = load_object_klass(not_null_obj); | 2902 Node* obj_klass = load_object_klass(not_null_obj); |
2734 | 2903 |
2771 if (tk->singleton()) { | 2940 if (tk->singleton()) { |
2772 const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr(); | 2941 const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr(); |
2773 if (objtp != NULL && objtp->klass() != NULL) { | 2942 if (objtp != NULL && objtp->klass() != NULL) { |
2774 switch (static_subtype_check(tk->klass(), objtp->klass())) { | 2943 switch (static_subtype_check(tk->klass(), objtp->klass())) { |
2775 case SSC_always_true: | 2944 case SSC_always_true: |
2776 return obj; | 2945 // If we know the type check always succeed then we don't use |
2946 // the profiling data at this bytecode. Don't lose it, feed it | |
2947 // to the type system as a speculative type. | |
2948 return record_profiled_receiver_for_speculation(obj); | |
2777 case SSC_always_false: | 2949 case SSC_always_false: |
2778 // It needs a null check because a null will *pass* the cast check. | 2950 // It needs a null check because a null will *pass* the cast check. |
2779 // A non-null value will always produce an exception. | 2951 // A non-null value will always produce an exception. |
2780 return null_assert(obj); | 2952 return null_assert(obj); |
2781 } | 2953 } |
2820 region->del_req(_null_path); | 2992 region->del_req(_null_path); |
2821 phi ->del_req(_null_path); | 2993 phi ->del_req(_null_path); |
2822 } | 2994 } |
2823 | 2995 |
2824 Node* cast_obj = NULL; | 2996 Node* cast_obj = NULL; |
2825 if (data != NULL && | 2997 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr(); |
2826 // Counter has never been decremented (due to cast failure). | 2998 // We may not have profiling here or it may not help us. If we have |
2827 // ...This is a reasonable thing to expect. It is true of | 2999 // a speculative type use it to perform an exact cast. |
2828 // all casts inserted by javac to implement generic types. | 3000 ciKlass* spec_obj_type = obj_type->speculative_type(); |
2829 data->as_CounterData()->count() >= 0) { | 3001 if (spec_obj_type != NULL || |
2830 cast_obj = maybe_cast_profiled_receiver(not_null_obj, data, tk->klass()); | 3002 (data != NULL && |
3003 // Counter has never been decremented (due to cast failure). | |
3004 // ...This is a reasonable thing to expect. It is true of | |
3005 // all casts inserted by javac to implement generic types. | |
3006 data->as_CounterData()->count() >= 0)) { | |
3007 cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace); | |
2831 if (cast_obj != NULL) { | 3008 if (cast_obj != NULL) { |
2832 if (failure_control != NULL) // failure is now impossible | 3009 if (failure_control != NULL) // failure is now impossible |
2833 (*failure_control) = top(); | 3010 (*failure_control) = top(); |
2834 // adjust the type of the phi to the exact klass: | 3011 // adjust the type of the phi to the exact klass: |
2835 phi->raise_bottom_type(_gvn.type(cast_obj)->meet(TypePtr::NULL_PTR)); | 3012 phi->raise_bottom_type(_gvn.type(cast_obj)->meet(TypePtr::NULL_PTR)); |