diff options
Diffstat (limited to 'gcc/tree-tailcall.c')
| -rw-r--r-- | gcc/tree-tailcall.c | 39 |
1 files changed, 6 insertions, 33 deletions
diff --git a/gcc/tree-tailcall.c b/gcc/tree-tailcall.c index e2e51a4..ec77c5f 100644 --- a/gcc/tree-tailcall.c +++ b/gcc/tree-tailcall.c @@ -390,7 +390,6 @@ find_tail_calls (basic_block bb, struct tailcall **ret) basic_block abb; size_t idx; tree var; - referenced_var_iterator rvi; if (!single_succ_p (bb)) return; @@ -484,7 +483,7 @@ find_tail_calls (basic_block bb, struct tailcall **ret) /* Make sure the tail invocation of this function does not refer to local variables. */ - FOR_EACH_REFERENCED_VAR (cfun, var, rvi) + FOR_EACH_LOCAL_DECL (cfun, idx, var) { if (TREE_CODE (var) != PARM_DECL && auto_var_in_fn_p (var, cfun->decl) @@ -872,36 +871,6 @@ eliminate_tail_call (struct tailcall *t) release_defs (call); } -/* Add phi nodes for the virtual operands defined in the function to the - header of the loop created by tail recursion elimination. - - Originally, we used to add phi nodes only for call clobbered variables, - as the value of the non-call clobbered ones obviously cannot be used - or changed within the recursive call. However, the local variables - from multiple calls now share the same location, so the virtual ssa form - requires us to say that the location dies on further iterations of the loop, - which requires adding phi nodes. -*/ -static void -add_virtual_phis (void) -{ - referenced_var_iterator rvi; - tree var; - - /* The problematic part is that there is no way how to know what - to put into phi nodes (there in fact does not have to be such - ssa name available). A solution would be to have an artificial - use/kill for all virtual operands in EXIT node. Unless we have - this, we cannot do much better than to rebuild the ssa form for - possibly affected virtual ssa names from scratch. */ - - FOR_EACH_REFERENCED_VAR (cfun, var, rvi) - { - if (!is_gimple_reg (var) && gimple_default_def (cfun, var) != NULL_TREE) - mark_sym_for_renaming (var); - } -} - /* Optimizes the tailcall described by T. If OPT_TAILCALLS is true, also mark the tailcalls for the sibcall optimization. */ @@ -1056,8 +1025,12 @@ tree_optimize_tail_calls_1 (bool opt_tailcalls) if (changed) free_dominance_info (CDI_DOMINATORS); + /* Add phi nodes for the virtual operands defined in the function to the + header of the loop created by tail recursion elimination. Do so + by triggering the SSA renamer. */ if (phis_constructed) - add_virtual_phis (); + mark_sym_for_renaming (gimple_vop (cfun)); + if (changed) return TODO_cleanup_cfg | TODO_update_ssa_only_virtuals; return 0; |