Mercurial > hg > graal-jvmci-8
diff src/share/vm/opto/divnode.cpp @ 6142:121e5708ae96
7169782: C2: SIGSEGV in LShiftLNode::Ideal(PhaseGVN*, bool)
Summary: keep intermediate node alive till the end of the graph construction using dummy hook node trick
Reviewed-by: kvn, twisti
Contributed-by: vladimir.x.ivanov@oracle.com
| author | kvn |
|---|---|
| date | Tue, 12 Jun 2012 09:47:23 -0700 |
| parents | f95d63e2154a |
| children | e626685e9f6c |
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--- a/src/share/vm/opto/divnode.cpp Tue Jun 12 10:02:36 2012 +0200 +++ b/src/share/vm/opto/divnode.cpp Tue Jun 12 09:47:23 2012 -0700 @@ -284,9 +284,14 @@ const int N = 64; + // Dummy node to keep intermediate nodes alive during construction + Node* hook = new (phase->C, 4) Node(4); + // u0 = u & 0xFFFFFFFF; u1 = u >> 32; Node* u0 = phase->transform(new (phase->C, 3) AndLNode(dividend, phase->longcon(0xFFFFFFFF))); Node* u1 = phase->transform(new (phase->C, 3) RShiftLNode(dividend, phase->intcon(N / 2))); + hook->init_req(0, u0); + hook->init_req(1, u1); // v0 = v & 0xFFFFFFFF; v1 = v >> 32; Node* v0 = phase->longcon(magic_const & 0xFFFFFFFF); @@ -299,19 +304,14 @@ Node* u1v0 = phase->transform(new (phase->C, 3) MulLNode(u1, v0)); Node* temp = phase->transform(new (phase->C, 3) URShiftLNode(w0, phase->intcon(N / 2))); Node* t = phase->transform(new (phase->C, 3) AddLNode(u1v0, temp)); + hook->init_req(2, t); // w1 = t & 0xFFFFFFFF; - Node* w1 = new (phase->C, 3) AndLNode(t, phase->longcon(0xFFFFFFFF)); + Node* w1 = phase->transform(new (phase->C, 3) AndLNode(t, phase->longcon(0xFFFFFFFF))); + hook->init_req(3, w1); // w2 = t >> 32; - Node* w2 = new (phase->C, 3) RShiftLNode(t, phase->intcon(N / 2)); - - // 6732154: Construct both w1 and w2 before transforming, so t - // doesn't go dead prematurely. - // 6837011: We need to transform w2 before w1 because the - // transformation of w1 could return t. - w2 = phase->transform(w2); - w1 = phase->transform(w1); + Node* w2 = phase->transform(new (phase->C, 3) RShiftLNode(t, phase->intcon(N / 2))); // w1 = u0*v1 + w1; Node* u0v1 = phase->transform(new (phase->C, 3) MulLNode(u0, v1)); @@ -322,6 +322,16 @@ Node* temp1 = phase->transform(new (phase->C, 3) AddLNode(u1v1, w2)); Node* temp2 = phase->transform(new (phase->C, 3) RShiftLNode(w1, phase->intcon(N / 2))); + // Remove the bogus extra edges used to keep things alive + PhaseIterGVN* igvn = phase->is_IterGVN(); + if (igvn != NULL) { + igvn->remove_dead_node(hook); + } else { + for (int i = 0; i < 4; i++) { + hook->set_req(i, NULL); + } + } + return new (phase->C, 3) AddLNode(temp1, temp2); }