From 960f0c9d4ccb8aab58523501f0e37749c526f18a Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Fri, 9 Dec 2011 12:48:30 +0100 Subject: [PATCH] re PR tree-optimization/51117 (rev.181172 causes glibc build failure) PR tree-optimization/51117 * tree-eh.c (optimize_clobbers): New function. (execute_lower_eh_dispatch): Call it. Co-Authored-By: Andrew Pinski From-SVN: r182158 --- gcc/ChangeLog | 7 +++++++ gcc/tree-eh.c | 31 ++++++++++++++++++++++++++++++- 2 files changed, 37 insertions(+), 1 deletion(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index d56c240d5ca..7dfa77fc54d 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2011-12-09 Jakub Jelinek + Andrew Pinski + + PR tree-optimization/51117 + * tree-eh.c (optimize_clobbers): New function. + (execute_lower_eh_dispatch): Call it. + 2011-12-09 Richard Guenther PR tree-optimization/51482 diff --git a/gcc/tree-eh.c b/gcc/tree-eh.c index 57abca80e4e..7fc850a2ae9 100644 --- a/gcc/tree-eh.c +++ b/gcc/tree-eh.c @@ -3173,6 +3173,30 @@ struct gimple_opt_pass pass_lower_resx = } }; +/* Try to optimize var = {v} {CLOBBER} stmts followed just by + external throw. */ + +static void +optimize_clobbers (basic_block bb) +{ + gimple_stmt_iterator gsi = gsi_last_bb (bb); + for (gsi_prev (&gsi); !gsi_end_p (gsi);) + { + gimple stmt = gsi_stmt (gsi); + if (is_gimple_debug (stmt)) + { + gsi_prev (&gsi); + continue; + } + if (!gimple_assign_single_p (stmt) + || TREE_CODE (gimple_assign_lhs (stmt)) == SSA_NAME + || !TREE_CLOBBER_P (gimple_assign_rhs1 (stmt))) + return; + unlink_stmt_vdef (stmt); + gsi_remove (&gsi, true); + release_defs (stmt); + } +} /* At the end of inlining, we can lower EH_DISPATCH. Return true when we have found some duplicate labels and removed some edges. */ @@ -3337,11 +3361,16 @@ execute_lower_eh_dispatch (void) FOR_EACH_BB (bb) { gimple last = last_stmt (bb); - if (last && gimple_code (last) == GIMPLE_EH_DISPATCH) + if (last == NULL) + continue; + if (gimple_code (last) == GIMPLE_EH_DISPATCH) { redirected |= lower_eh_dispatch (bb, last); any_rewritten = true; } + else if (gimple_code (last) == GIMPLE_RESX + && stmt_can_throw_external (last)) + optimize_clobbers (bb); } if (redirected)