diff options
Diffstat (limited to 'gcc/tree-ssa-live.c')
| -rw-r--r-- | gcc/tree-ssa-live.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/gcc/tree-ssa-live.c b/gcc/tree-ssa-live.c index 8c02a2b4b66..e011a5d250c 100644 --- a/gcc/tree-ssa-live.c +++ b/gcc/tree-ssa-live.c @@ -296,6 +296,9 @@ mark_all_vars_used_1 (tree *tp, int *walk_subtrees, { tree t = *tp; + if (TREE_CODE (t) == SSA_NAME) + t = SSA_NAME_VAR (t); + /* Ignore TREE_ORIGINAL for TARGET_MEM_REFS, as well as other fields that do not contain vars. */ if (TREE_CODE (t) == TARGET_MEM_REF) @@ -327,6 +330,72 @@ mark_all_vars_used (tree *expr_p) walk_tree (expr_p, mark_all_vars_used_1, NULL, NULL); } + +/* Remove local variables that are not referenced in the IL. */ + +void +remove_unused_locals (void) +{ + basic_block bb; + tree t, *cell; + + /* Assume all locals are unused. */ + for (t = cfun->unexpanded_var_list; t; t = TREE_CHAIN (t)) + { + tree var = TREE_VALUE (t); + if (TREE_CODE (var) != FUNCTION_DECL + && var_ann (var)) + var_ann (var)->used = false; + } + + /* Walk the CFG marking all referenced symbols. */ + FOR_EACH_BB (bb) + { + block_stmt_iterator bsi; + tree phi, def; + + /* Walk the statements. */ + for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) + mark_all_vars_used (bsi_stmt_ptr (bsi)); + + for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) + { + use_operand_p arg_p; + ssa_op_iter i; + + /* No point processing globals. */ + if (is_global_var (SSA_NAME_VAR (PHI_RESULT (phi)))) + continue; + + def = PHI_RESULT (phi); + mark_all_vars_used (&def); + + FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_ALL_USES) + { + tree arg = USE_FROM_PTR (arg_p); + mark_all_vars_used (&arg); + } + } + } + + /* Remove unmarked vars and clear used flag. */ + for (cell = &cfun->unexpanded_var_list; *cell; ) + { + tree var = TREE_VALUE (*cell); + var_ann_t ann; + + if (TREE_CODE (var) != FUNCTION_DECL + && (!(ann = var_ann (var)) + || !ann->used)) + { + *cell = TREE_CHAIN (*cell); + continue; + } + + cell = &TREE_CHAIN (*cell); + } +} + /* This function looks through the program and uses FLAGS to determine what SSA versioned variables are given entries in a new partition table. This new partition map is returned. */ @@ -362,6 +431,7 @@ create_ssa_var_map (int flags) FOR_EACH_BB (bb) { tree phi, arg; + for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) { int i; |