diff options
Diffstat (limited to 'gcc/cfgexpand.c')
| -rw-r--r-- | gcc/cfgexpand.c | 132 |
1 files changed, 126 insertions, 6 deletions
diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c index 53beecd..d9b5774 100644 --- a/gcc/cfgexpand.c +++ b/gcc/cfgexpand.c @@ -2338,7 +2338,10 @@ expand_debug_expr (tree exp) if (inner_mode == VOIDmode) { - inner_mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0))); + if (TREE_CODE (exp) == SSA_NAME) + inner_mode = TYPE_MODE (TREE_TYPE (exp)); + else + inner_mode = TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp, 0))); if (mode == inner_mode) return op0; } @@ -2354,6 +2357,7 @@ expand_debug_expr (tree exp) } else if (FLOAT_MODE_P (mode)) { + gcc_assert (TREE_CODE (exp) != SSA_NAME); if (TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (exp, 0)))) op0 = simplify_gen_unary (UNSIGNED_FLOAT, mode, op0, inner_mode); else @@ -2886,14 +2890,24 @@ expand_debug_expr (tree exp) case SSA_NAME: { - int part = var_to_partition (SA.map, exp); + gimple g = get_gimple_for_ssa_name (exp); + if (g) + { + op0 = expand_debug_expr (gimple_assign_rhs_to_tree (g)); + if (!op0) + return NULL; + } + else + { + int part = var_to_partition (SA.map, exp); - if (part == NO_PARTITION) - return NULL; + if (part == NO_PARTITION) + return NULL; - gcc_assert (part >= 0 && (unsigned)part < SA.map->num_partitions); + gcc_assert (part >= 0 && (unsigned)part < SA.map->num_partitions); - op0 = SA.partition_to_pseudo[part]; + op0 = SA.partition_to_pseudo[part]; + } goto adjust_mode; } @@ -3050,6 +3064,105 @@ expand_gimple_basic_block (basic_block bb) basic_block new_bb; stmt = gsi_stmt (gsi); + + /* If this statement is a non-debug one, and we generate debug + insns, then this one might be the last real use of a TERed + SSA_NAME, but where there are still some debug uses further + down. Expanding the current SSA name in such further debug + uses by their RHS might lead to wrong debug info, as coalescing + might make the operands of such RHS be placed into the same + pseudo as something else. Like so: + a_1 = a_0 + 1; // Assume a_1 is TERed and a_0 is dead + use(a_1); + a_2 = ... + #DEBUG ... => a_1 + As a_0 and a_2 don't overlap in lifetime, assume they are coalesced. + If we now would expand a_1 by it's RHS (a_0 + 1) in the debug use, + the write to a_2 would actually have clobbered the place which + formerly held a_0. + + So, instead of that, we recognize the situation, and generate + debug temporaries at the last real use of TERed SSA names: + a_1 = a_0 + 1; + #DEBUG #D1 => a_1 + use(a_1); + a_2 = ... + #DEBUG ... => #D1 + */ + if (MAY_HAVE_DEBUG_INSNS + && SA.values + && !is_gimple_debug (stmt)) + { + ssa_op_iter iter; + tree op; + gimple def; + + location_t sloc = get_curr_insn_source_location (); + tree sblock = get_curr_insn_block (); + + /* Look for SSA names that have their last use here (TERed + names always have only one real use). */ + FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_USE) + if ((def = get_gimple_for_ssa_name (op))) + { + imm_use_iterator imm_iter; + use_operand_p use_p; + bool have_debug_uses = false; + + FOR_EACH_IMM_USE_FAST (use_p, imm_iter, op) + { + if (gimple_debug_bind_p (USE_STMT (use_p))) + { + have_debug_uses = true; + break; + } + } + + if (have_debug_uses) + { + /* OP is a TERed SSA name, with DEF it's defining + statement, and where OP is used in further debug + instructions. Generate a debug temporary, and + replace all uses of OP in debug insns with that + temporary. */ + gimple debugstmt; + tree value = gimple_assign_rhs_to_tree (def); + tree vexpr = make_node (DEBUG_EXPR_DECL); + rtx val; + enum machine_mode mode; + + set_curr_insn_source_location (gimple_location (def)); + set_curr_insn_block (gimple_block (def)); + + DECL_ARTIFICIAL (vexpr) = 1; + TREE_TYPE (vexpr) = TREE_TYPE (value); + if (DECL_P (value)) + mode = DECL_MODE (value); + else + mode = TYPE_MODE (TREE_TYPE (value)); + DECL_MODE (vexpr) = mode; + + val = gen_rtx_VAR_LOCATION + (mode, vexpr, (rtx)value, VAR_INIT_STATUS_INITIALIZED); + + val = emit_debug_insn (val); + + FOR_EACH_IMM_USE_STMT (debugstmt, imm_iter, op) + { + if (!gimple_debug_bind_p (debugstmt)) + continue; + + FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter) + SET_USE (use_p, vexpr); + + update_stmt (debugstmt); + } + } + } + set_curr_insn_source_location (sloc); + set_curr_insn_block (sblock); + } + currently_expanding_gimple_stmt = stmt; /* Expand this statement, then evaluate the resulting RTL and @@ -3102,6 +3215,13 @@ expand_gimple_basic_block (basic_block bb) INSN_VAR_LOCATION_LOC (val) = (rtx)value; } + /* In order not to generate too many debug temporaries, + we delink all uses of debug statements we already expanded. + Therefore debug statements between definition and real + use of TERed SSA names will continue to use the SSA name, + and not be replaced with debug temps. */ + delink_stmt_imm_use (stmt); + gsi = nsi; gsi_next (&nsi); if (gsi_end_p (nsi)) |