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comparison src/share/vm/opto/parse2.cpp @ 37:73970d8c0b27

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6671250: In Parse::do_if() old Cmp node 'c' should be replaced with new one after BoolNode transformation Summary: In Parse::do_if() 'c' (CmpNode) node may be changed during BoolNode transformation so 'c' may became dead but the node is referenced later in the code. Reviewed-by: never
author kvn
date Wed, 05 Mar 2008 11:33:31 -0800
parents ff5961f4c095
children ba764ed4b6f2
comparison
equal deleted inserted replaced
36:f34d9da7acb2 37:73970d8c0b27
1020 1020
1021 Node* tst0 = new (C, 2) BoolNode(c, btest); 1021 Node* tst0 = new (C, 2) BoolNode(c, btest);
1022 Node* tst = _gvn.transform(tst0); 1022 Node* tst = _gvn.transform(tst0);
1023 BoolTest::mask taken_btest = BoolTest::illegal; 1023 BoolTest::mask taken_btest = BoolTest::illegal;
1024 BoolTest::mask untaken_btest = BoolTest::illegal; 1024 BoolTest::mask untaken_btest = BoolTest::illegal;
1025 if (btest == BoolTest::ne) { 1025
1026 // For now, these are the only cases of btest that matter. (More later.) 1026 if (tst->is_Bool()) {
1027 taken_btest = taken_if_true ? btest : BoolTest::eq; 1027 // Refresh c from the transformed bool node, since it may be
1028 untaken_btest = taken_if_true ? BoolTest::eq : btest; 1028 // simpler than the original c. Also re-canonicalize btest.
1029 // This wins when (Bool ne (Conv2B p) 0) => (Bool ne (CmpP p NULL)).
1030 // That can arise from statements like: if (x instanceof C) ...
1031 if (tst != tst0) {
1032 // Canonicalize one more time since transform can change it.
1033 btest = tst->as_Bool()->_test._test;
1034 if (!BoolTest(btest).is_canonical()) {
1035 // Reverse edges one more time...
1036 tst = _gvn.transform( tst->as_Bool()->negate(&_gvn) );
1037 btest = tst->as_Bool()->_test._test;
1038 assert(BoolTest(btest).is_canonical(), "sanity");
1039 taken_if_true = !taken_if_true;
1040 }
1041 c = tst->in(1);
1042 }
1043 BoolTest::mask neg_btest = BoolTest(btest).negate();
1044 taken_btest = taken_if_true ? btest : neg_btest;
1045 untaken_btest = taken_if_true ? neg_btest : btest;
1029 } 1046 }
1030 1047
1031 // Generate real control flow 1048 // Generate real control flow
1032 float true_prob = (taken_if_true ? prob : untaken_prob); 1049 float true_prob = (taken_if_true ? prob : untaken_prob);
1033 IfNode* iff = create_and_map_if(control(), tst, true_prob, cnt); 1050 IfNode* iff = create_and_map_if(control(), tst, true_prob, cnt);