- BugFix: do NOT do the copy-return optimization if there might be access to the...

[r19988]

diff --git a/ir/lower/lower_calls.c b/ir/lower/lower_calls.c
index 6b4d410..c1ec226 100644 (file)
--- a/ir/lower/lower_calls.c
+++ b/ir/lower/lower_calls.c
@@ -201,14 +201,15 @@ struct cl_entry {
  * Walker environment for fix_args_and_collect_calls().
  */
 typedef struct _wlk_env_t {
-       int                  arg_shift;     /**< The Argument index shift for parameters. */
-       int                  first_hidden;  /**< The index of the first hidden argument. */
-       struct obstack       obst;          /**< An obstack to allocate the data on. */
-       cl_entry             *cl_list;      /**< The call list. */
-       pmap                 *dummy_map;    /**< A map for finding the dummy arguments. */
-       unsigned             dnr;           /**< The dummy index number. */
-       const lower_params_t *params;       /**< lowering parameters */
-       int                  changed;       /**< set if the current graph was changed */
+       int                  arg_shift;       /**< The Argument index shift for parameters. */
+       int                  first_hidden;    /**< The index of the first hidden argument. */
+       struct obstack       obst;            /**< An obstack to allocate the data on. */
+       cl_entry             *cl_list;        /**< The call list. */
+       pmap                 *dummy_map;      /**< A map for finding the dummy arguments. */
+       unsigned             dnr;             /**< The dummy index number. */
+       const lower_params_t *params;         /**< Lowering parameters. */
+       unsigned             non_local_mem:1; /**< Set if non-local memory access was found. */
+       unsigned             changed:1;       /**< Set if the current graph was changed. */
 } wlk_env;
 
 /**
@@ -240,9 +241,16 @@ static void fix_args_and_collect_calls(ir_node *n, void *ctx) {
        wlk_env *env = ctx;
        int i;
        ir_type *ctp;
-       ir_op *op = get_irn_op(n);
+       ir_opcode code = get_irn_opcode(n);
 
-       if (env->arg_shift > 0 && op == op_Proj) {
+       if (code == iro_Load || code == iro_Store) {
+               ir_node *ptr = get_irn_n(n, 1);
+
+               if (! is_Sel(ptr))
+                       env->non_local_mem = 1;
+               else if (get_Sel_ptr(ptr) != get_irg_frame(current_ir_graph))
+                       env->non_local_mem = 1;
+       } else if (env->arg_shift > 0 && code == iro_Proj) {
                ir_node *pred = get_Proj_pred(n);
 
                /* Fix the argument numbers */
@@ -251,7 +259,7 @@ static void fix_args_and_collect_calls(ir_node *n, void *ctx) {
                        set_Proj_proj(n, pnr + env->arg_shift);
                        env->changed = 1;
                }
-       } else if (op == op_Call) {
+       } else if (code == iro_Call) {
                ctp = get_Call_type(n);
                if (env->params->flags & LF_COMPOUND_RETURN) {
                        /* check for compound returns */
@@ -266,7 +274,7 @@ static void fix_args_and_collect_calls(ir_node *n, void *ctx) {
                                }
                        }
                }
-       } else if (op == op_CopyB && env->params->flags & LF_COMPOUND_RETURN) {
+       } else if (code == iro_CopyB && env->params->flags & LF_COMPOUND_RETURN) {
                /* check for compound returns */
                ir_node *src = get_CopyB_src(n);
                /* older scheme using value_res_ent */
@@ -281,7 +289,7 @@ static void fix_args_and_collect_calls(ir_node *n, void *ctx) {
                                        e->copyb = n;
                                }
                        }
-               } else
+               } else {
                        /* new scheme: compound results are determined by the call type only */
                        if (is_Proj(src)) {
                                ir_node *proj = get_Proj_pred(src);
@@ -298,6 +306,7 @@ static void fix_args_and_collect_calls(ir_node *n, void *ctx) {
                                        }
                                }
                        }
+               }
        }
 }
 
@@ -423,11 +432,10 @@ static void add_hidden_param(ir_graph *irg, int n_com, ir_node **ins, cl_entry *
                                if (get_struct_member(owner, idx) == ent)
                                        break;
                        assert(idx < get_struct_n_members(owner));
-               }
-               else
-
+               } else {
                        /* new scheme: compound returns are determined by the call type and are Proj's */
                        idx = get_Proj_proj(src);
+               }
 
                ins[idx] = get_CopyB_dst(p);
                mem      = get_CopyB_mem(p);
@@ -526,14 +534,17 @@ static void fix_call_list(ir_graph *irg, wlk_env *env) {
  */
 static void transform_irg(const lower_params_t *lp, ir_graph *irg)
 {
-       ir_entity *ent = get_irg_entity(irg);
-       ir_type *mtp, *lowered_mtp, *tp, *ft;
-       int i, j, k, n_ress = 0, n_ret_com = 0, n_cr_opt;
-       ir_node **new_in, *ret, *endbl, *bl, *mem, *copy;
-       cr_pair *cr_opt;
-       wlk_env env;
+       ir_graph   * rem = current_ir_graph;
+       ir_entity  *ent = get_irg_entity(irg);
+       ir_type    *mtp, *lowered_mtp, *tp, *ft;
+       int        i, j, k, n_ress = 0, n_ret_com = 0, n_cr_opt;
+       ir_node    **new_in, *ret, *endbl, *bl, *mem, *copy;
+       cr_pair    *cr_opt;
+       wlk_env    env;
        add_hidden hidden_params;
 
+       current_ir_graph = irg;
+
        assert(ent && "Cannot transform graph without an entity");
        assert(get_irg_phase_state(irg) == phase_high && "call lowering must be done in phase high");
 
@@ -567,8 +578,7 @@ static void transform_irg(const lower_params_t *lp, ir_graph *irg)
                        /* hidden arguments are added first */
                        env.arg_shift    = n_ret_com;
                        env.first_hidden = 0;
-               }
-               else {
+               } else {
                        /* hidden arguments are added last */
                        env.arg_shift    = 0;
                        env.first_hidden = get_method_n_params(mtp);
@@ -578,11 +588,12 @@ static void transform_irg(const lower_params_t *lp, ir_graph *irg)
                env.arg_shift = 0;
        }
        obstack_init(&env.obst);
-       env.cl_list   = NULL;
-       env.dummy_map = pmap_create_ex(8);
-       env.dnr       = 0;
-       env.params    = lp;
-       env.changed   = 0;
+       env.cl_list       = NULL;
+       env.dummy_map     = pmap_create_ex(8);
+       env.dnr           = 0;
+       env.params        = lp;
+       env.non_local_mem = 0;
+       env.changed       = 0;
 
        /* scan the code, fix argument numbers and collect calls. */
        irg_walk_graph(irg, firm_clear_link, fix_args_and_collect_calls, &env);
@@ -595,8 +606,8 @@ static void transform_irg(const lower_params_t *lp, ir_graph *irg)
 
        if (n_ret_com) {
                /*
-               * Now fix the Return node of the current graph.
-               */
+                * Now fix the Return node of the current graph.
+                */
                env.changed = 1;
 
                /* STEP 1: find the return. This is simple, we have normalized the graph. */
@@ -638,7 +649,14 @@ static void transform_irg(const lower_params_t *lp, ir_graph *irg)
                                        /* The Return(Unknown) is the Firm construct for a missing return.
                                           Do nothing. */
                                } else {
-                                       if (is_compound_address(ft, pred)) {
+                                       /**
+                                        * Sorrily detecting that copy-return is possible isn't that simple.
+                                        * We must check, that the hidden address is alias free during the whole
+                                        * function.
+                                        * A simple heuristic: all Loads/Stores inside
+                                        * the function access only local frame.
+                                        */
+                                       if (!env.non_local_mem && is_compound_address(ft, pred)) {
                                                /* we can do the copy-return optimization here */
                                                cr_opt[n_cr_opt].ent = get_Sel_entity(pred);
                                                cr_opt[n_cr_opt].arg = arg;
@@ -684,6 +702,7 @@ static void transform_irg(const lower_params_t *lp, ir_graph *irg)
                set_irg_outs_inconsistent(irg);
                set_irg_loopinfo_state(irg, loopinfo_inconsistent);
        }
+       current_ir_graph = rem;
 }
 
 /**