From c08b0d3f7b3539b26031de31d88dea6b94474577 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Mon, 27 May 2024 10:41:02 +0200 Subject: [PATCH] tree-optimization/115236 - more points-to *ANYTHING = x fixes The stored-to ANYTHING handling has more holes, uncovered by treating volatile accesses as ANYTHING. We fail to properly build the pred and succ graphs, in particular we may not elide direct nodes from receiving from STOREDANYTHING. PR tree-optimization/115236 * tree-ssa-structalias.cc (build_pred_graph): Properly handle *ANYTHING = X. (build_succ_graph): Likewise. Do not elide direct nodes from receiving from STOREDANYTHING. * gcc.dg/pr115236.c: New testcase. --- gcc/testsuite/gcc.dg/pr115236.c | 12 ++++++++++++ gcc/tree-ssa-structalias.cc | 20 ++++++++++++++------ 2 files changed, 26 insertions(+), 6 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/pr115236.c diff --git a/gcc/testsuite/gcc.dg/pr115236.c b/gcc/testsuite/gcc.dg/pr115236.c new file mode 100644 index 000000000000..91edfab957ac --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr115236.c @@ -0,0 +1,12 @@ +/* { dg-do run } */ +/* { dg-options "-O -fno-tree-fre" } */ + +int a, *b = &a; +int main() +{ + int *c, *volatile *d = &c; + *d = b; + if (c != &a) + __builtin_abort(); + return 0; +} diff --git a/gcc/tree-ssa-structalias.cc b/gcc/tree-ssa-structalias.cc index 9cec2c6cfd97..330e64e65da1 100644 --- a/gcc/tree-ssa-structalias.cc +++ b/gcc/tree-ssa-structalias.cc @@ -1312,7 +1312,12 @@ build_pred_graph (void) { /* *x = y. */ if (rhs.offset == 0 && lhs.offset == 0 && rhs.type == SCALAR) - add_pred_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar); + { + if (lhs.var == anything_id) + add_pred_graph_edge (graph, storedanything_id, rhsvar); + else + add_pred_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar); + } } else if (rhs.type == DEREF) { @@ -1398,7 +1403,12 @@ build_succ_graph (void) if (lhs.type == DEREF) { if (rhs.offset == 0 && lhs.offset == 0 && rhs.type == SCALAR) - add_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar); + { + if (lhs.var == anything_id) + add_graph_edge (graph, storedanything_id, rhsvar); + else + add_graph_edge (graph, FIRST_REF_NODE + lhsvar, rhsvar); + } } else if (rhs.type == DEREF) { @@ -1418,13 +1428,11 @@ build_succ_graph (void) } } - /* Add edges from STOREDANYTHING to all non-direct nodes that can - receive pointers. */ + /* Add edges from STOREDANYTHING to all nodes that can receive pointers. */ t = find (storedanything_id); for (i = integer_id + 1; i < FIRST_REF_NODE; ++i) { - if (!bitmap_bit_p (graph->direct_nodes, i) - && get_varinfo (i)->may_have_pointers) + if (get_varinfo (i)->may_have_pointers) add_graph_edge (graph, find (i), t); } -- 2.47.2