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comparison src/share/vm/opto/parse2.cpp @ 129:c0939256690b

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6646019: array subscript expressions become top() with -d64 Summary: stop compilation after negative array allocation Reviewed-by: never, jrose
author rasbold
date Thu, 24 Apr 2008 14:02:13 -0700
parents ba764ed4b6f2
children d1605aabd0a1 1e026f8da827
comparison
equal deleted inserted replaced
127:e0bd2e08e3d0 129:c0939256690b
103 103
104 // Do the range check 104 // Do the range check
105 if (GenerateRangeChecks && need_range_check) { 105 if (GenerateRangeChecks && need_range_check) {
106 // Range is constant in array-oop, so we can use the original state of mem 106 // Range is constant in array-oop, so we can use the original state of mem
107 Node* len = load_array_length(ary); 107 Node* len = load_array_length(ary);
108 // Test length vs index (standard trick using unsigned compare) 108 Node* tst;
109 Node* chk = _gvn.transform( new (C, 3) CmpUNode(idx, len) ); 109 if (sizetype->_hi <= 0) {
110 BoolTest::mask btest = BoolTest::lt; 110 // If the greatest array bound is negative, we can conclude that we're
111 Node* tst = _gvn.transform( new (C, 2) BoolNode(chk, btest) ); 111 // compiling unreachable code, but the unsigned compare trick used below
112 // only works with non-negative lengths. Instead, hack "tst" to be zero so
113 // the uncommon_trap path will always be taken.
114 tst = _gvn.intcon(0);
115 } else {
116 // Test length vs index (standard trick using unsigned compare)
117 Node* chk = _gvn.transform( new (C, 3) CmpUNode(idx, len) );
118 BoolTest::mask btest = BoolTest::lt;
119 tst = _gvn.transform( new (C, 2) BoolNode(chk, btest) );
120 }
112 // Branch to failure if out of bounds 121 // Branch to failure if out of bounds
113 { BuildCutout unless(this, tst, PROB_MAX); 122 { BuildCutout unless(this, tst, PROB_MAX);
114 if (C->allow_range_check_smearing()) { 123 if (C->allow_range_check_smearing()) {
115 // Do not use builtin_throw, since range checks are sometimes 124 // Do not use builtin_throw, since range checks are sometimes
116 // made more stringent by an optimistic transformation. 125 // made more stringent by an optimistic transformation.