From 86efc490ab86bfa00720479b4714da23cd7df797 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Wed, 29 Mar 2023 11:59:16 +0200 Subject: [PATCH] tree-optimization/109331 - make sure to clean up the CFG after forwprop When forwprop discovers unreachable code or makes decisions based on unreachable edges make sure to cleanup the CFG since otherwise SSA form can become invalid. PR tree-optimization/109331 * tree-ssa-forwprop.cc (pass_forwprop::execute): When we discover a taken edge make sure to cleanup the CFG. * gcc.dg/torture/pr109331.c: New testcase. --- gcc/testsuite/gcc.dg/torture/pr109331.c | 16 ++++++++++++++++ gcc/tree-ssa-forwprop.cc | 6 +++++- 2 files changed, 21 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gcc.dg/torture/pr109331.c diff --git a/gcc/testsuite/gcc.dg/torture/pr109331.c b/gcc/testsuite/gcc.dg/torture/pr109331.c new file mode 100644 index 000000000000..72c57b9b74ca --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr109331.c @@ -0,0 +1,16 @@ +/* { dg-do compile } */ + +char *ustol_dpp; +void ustol(int flags) +{ + char *s; + if (s) + flags |= 3; + switch (flags & 3) + case 3: + while (*s) + case '+': + ++s; + if (flags) + ustol_dpp = s; +} diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc index bb0fa306312f..9b567440ba4f 100644 --- a/gcc/tree-ssa-forwprop.cc +++ b/gcc/tree-ssa-forwprop.cc @@ -4046,7 +4046,11 @@ pass_forwprop::execute (function *fun) /* Mark outgoing exectuable edges. */ if (edge e = find_taken_edge (bb, NULL)) - e->flags |= EDGE_EXECUTABLE; + { + e->flags |= EDGE_EXECUTABLE; + if (EDGE_COUNT (bb->succs) > 1) + cfg_changed = true; + } else { FOR_EACH_EDGE (e, ei, bb->succs) -- 2.47.2