diff options
Diffstat (limited to 'gcc/tree-eh.c')
| -rw-r--r-- | gcc/tree-eh.c | 67 |
1 files changed, 58 insertions, 9 deletions
diff --git a/gcc/tree-eh.c b/gcc/tree-eh.c index 973782b..2eb3097 100644 --- a/gcc/tree-eh.c +++ b/gcc/tree-eh.c @@ -3230,14 +3230,48 @@ static void optimize_clobbers (basic_block bb) { gimple_stmt_iterator gsi = gsi_last_bb (bb); + bool any_clobbers = false; + bool seen_stack_restore = false; + edge_iterator ei; + edge e; + + /* Only optimize anything if the bb contains at least one clobber, + ends with resx (checked by caller), optionally contains some + debug stmts or labels, or at most one __builtin_stack_restore + call, and has an incoming EH edge. */ for (gsi_prev (&gsi); !gsi_end_p (gsi); gsi_prev (&gsi)) { gimple stmt = gsi_stmt (gsi); if (is_gimple_debug (stmt)) continue; - if (!gimple_clobber_p (stmt) - || TREE_CODE (gimple_assign_lhs (stmt)) == SSA_NAME) - return; + if (gimple_clobber_p (stmt)) + { + any_clobbers = true; + continue; + } + if (!seen_stack_restore + && gimple_call_builtin_p (stmt, BUILT_IN_STACK_RESTORE)) + { + seen_stack_restore = true; + continue; + } + if (gimple_code (stmt) == GIMPLE_LABEL) + break; + return; + } + if (!any_clobbers) + return; + FOR_EACH_EDGE (e, ei, bb->preds) + if (e->flags & EDGE_EH) + break; + if (e == NULL) + return; + gsi = gsi_last_bb (bb); + for (gsi_prev (&gsi); !gsi_end_p (gsi); gsi_prev (&gsi)) + { + gimple stmt = gsi_stmt (gsi); + if (!gimple_clobber_p (stmt)) + continue; unlink_stmt_vdef (stmt); gsi_remove (&gsi, true); release_defs (stmt); @@ -3278,8 +3312,7 @@ sink_clobbers (basic_block bb) continue; if (gimple_code (stmt) == GIMPLE_LABEL) break; - if (!gimple_clobber_p (stmt) - || TREE_CODE (gimple_assign_lhs (stmt)) == SSA_NAME) + if (!gimple_clobber_p (stmt)) return 0; any_clobbers = true; } @@ -3292,11 +3325,27 @@ sink_clobbers (basic_block bb) for (gsi_prev (&gsi); !gsi_end_p (gsi); gsi_prev (&gsi)) { gimple stmt = gsi_stmt (gsi); + tree lhs; if (is_gimple_debug (stmt)) continue; if (gimple_code (stmt) == GIMPLE_LABEL) break; unlink_stmt_vdef (stmt); + lhs = gimple_assign_lhs (stmt); + /* Unfortunately we don't have dominance info updated at this + point, so checking if + dominated_by_p (CDI_DOMINATORS, succbb, + gimple_bb (SSA_NAME_DEF_STMT (TREE_OPERAND (lhs, 0))) + would be too costly. Thus, avoid sinking any clobbers that + refer to non-(D) SSA_NAMEs. */ + if (TREE_CODE (lhs) == MEM_REF + && TREE_CODE (TREE_OPERAND (lhs, 0)) == SSA_NAME + && !SSA_NAME_IS_DEFAULT_DEF (TREE_OPERAND (lhs, 0))) + { + gsi_remove (&gsi, true); + release_defs (stmt); + continue; + } gsi_remove (&gsi, false); /* Trigger the operand scanner to cause renaming for virtual operands for this statement. @@ -3737,10 +3786,10 @@ unsplit_eh (eh_landing_pad lp) edge e_in, e_out; /* Quickly check the edge counts on BB for singularity. */ - if (EDGE_COUNT (bb->preds) != 1 || EDGE_COUNT (bb->succs) != 1) + if (!single_pred_p (bb) || !single_succ_p (bb)) return false; - e_in = EDGE_PRED (bb, 0); - e_out = EDGE_SUCC (bb, 0); + e_in = single_pred_edge (bb); + e_out = single_succ_edge (bb); /* Input edge must be EH and output edge must be normal. */ if ((e_in->flags & EDGE_EH) == 0 || (e_out->flags & EDGE_EH) != 0) @@ -4142,7 +4191,7 @@ cleanup_empty_eh (eh_landing_pad lp) e_out = NULL; break; case 1: - e_out = EDGE_SUCC (bb, 0); + e_out = single_succ_edge (bb); break; default: return false; |