Mercurial > hg > graal-compiler
diff src/share/vm/opto/compile.cpp @ 1172:b2b6a9bf6238
6894779: Loop Predication for Loop Optimizer in C2
Summary: Loop predication implementation
Reviewed-by: never, kvn
author | cfang |
---|---|
date | Tue, 12 Jan 2010 14:37:35 -0800 |
parents | f96a1a986f7b |
children | b4b440360f1e |
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--- a/src/share/vm/opto/compile.cpp Sat Jan 09 00:59:35 2010 -0800 +++ b/src/share/vm/opto/compile.cpp Tue Jan 12 14:37:35 2010 -0800 @@ -932,6 +932,7 @@ _intrinsics = NULL; _macro_nodes = new GrowableArray<Node*>(comp_arena(), 8, 0, NULL); + _predicate_opaqs = new GrowableArray<Node*>(comp_arena(), 8, 0, NULL); register_library_intrinsics(); } @@ -1553,6 +1554,19 @@ } } +//---------------------cleanup_loop_predicates----------------------- +// Remove the opaque nodes that protect the predicates so that all unused +// checks and uncommon_traps will be eliminated from the ideal graph +void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) { + if (predicate_count()==0) return; + for (int i = predicate_count(); i > 0; i--) { + Node * n = predicate_opaque1_node(i-1); + assert(n->Opcode() == Op_Opaque1, "must be"); + igvn.replace_node(n, n->in(1)); + } + assert(predicate_count()==0, "should be clean!"); + igvn.optimize(); +} //------------------------------Optimize--------------------------------------- // Given a graph, optimize it. @@ -1594,7 +1608,7 @@ if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) { { TracePhase t2("idealLoop", &_t_idealLoop, true); - PhaseIdealLoop ideal_loop( igvn, true ); + PhaseIdealLoop ideal_loop( igvn, true, UseLoopPredicate); loop_opts_cnt--; if (major_progress()) print_method("PhaseIdealLoop 1", 2); if (failing()) return; @@ -1602,7 +1616,7 @@ // Loop opts pass if partial peeling occurred in previous pass if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) { TracePhase t3("idealLoop", &_t_idealLoop, true); - PhaseIdealLoop ideal_loop( igvn, false ); + PhaseIdealLoop ideal_loop( igvn, false, UseLoopPredicate); loop_opts_cnt--; if (major_progress()) print_method("PhaseIdealLoop 2", 2); if (failing()) return; @@ -1610,7 +1624,7 @@ // Loop opts pass for loop-unrolling before CCP if(major_progress() && (loop_opts_cnt > 0)) { TracePhase t4("idealLoop", &_t_idealLoop, true); - PhaseIdealLoop ideal_loop( igvn, false ); + PhaseIdealLoop ideal_loop( igvn, false, UseLoopPredicate); loop_opts_cnt--; if (major_progress()) print_method("PhaseIdealLoop 3", 2); } @@ -1648,13 +1662,21 @@ // peeling, unrolling, etc. if(loop_opts_cnt > 0) { debug_only( int cnt = 0; ); + bool loop_predication = UseLoopPredicate; while(major_progress() && (loop_opts_cnt > 0)) { TracePhase t2("idealLoop", &_t_idealLoop, true); assert( cnt++ < 40, "infinite cycle in loop optimization" ); - PhaseIdealLoop ideal_loop( igvn, true ); + PhaseIdealLoop ideal_loop( igvn, true, loop_predication); loop_opts_cnt--; if (major_progress()) print_method("PhaseIdealLoop iterations", 2); if (failing()) return; + // Perform loop predication optimization during first iteration after CCP. + // After that switch it off and cleanup unused loop predicates. + if (loop_predication) { + loop_predication = false; + cleanup_loop_predicates(igvn); + if (failing()) return; + } } }