diff options
Diffstat (limited to 'gcc/function.c')
| -rw-r--r-- | gcc/function.c | 275 |
1 files changed, 225 insertions, 50 deletions
diff --git a/gcc/function.c b/gcc/function.c index f9d11bf..c3d00cd 100644 --- a/gcc/function.c +++ b/gcc/function.c @@ -72,6 +72,9 @@ along with GCC; see the file COPYING3. If not see #include "cfganal.h" #include "cfgbuild.h" #include "cfgcleanup.h" +#include "cfgexpand.h" +#include "basic-block.h" +#include "df.h" #include "params.h" #include "bb-reorder.h" #include "shrink-wrap.h" @@ -148,6 +151,8 @@ static bool contains (const_rtx, hash_table<insn_cache_hasher> *); static void prepare_function_start (void); static void do_clobber_return_reg (rtx, void *); static void do_use_return_reg (rtx, void *); +static rtx rtl_for_parm (struct assign_parm_data_all *, tree); + /* Stack of nested functions. */ /* Keep track of the cfun stack. */ @@ -2105,6 +2110,30 @@ aggregate_value_p (const_tree exp, const_tree fntype) bool use_register_for_decl (const_tree decl) { + if (TREE_CODE (decl) == SSA_NAME) + { + /* We often try to use the SSA_NAME, instead of its underlying + decl, to get type information and guide decisions, to avoid + differences of behavior between anonymous and named + variables, but in this one case we have to go for the actual + variable if there is one. The main reason is that, at least + at -O0, we want to place user variables on the stack, but we + don't mind using pseudos for anonymous or ignored temps. + Should we take the SSA_NAME, we'd conclude all SSA_NAMEs + should go in pseudos, whereas their corresponding variables + might have to go on the stack. So, disregarding the decl + here would negatively impact debug info at -O0, enable + coalescing between SSA_NAMEs that ought to get different + stack/pseudo assignments, and get the incoming argument + processing thoroughly confused by PARM_DECLs expected to live + in stack slots but assigned to pseudos. */ + if (!SSA_NAME_VAR (decl)) + return TYPE_MODE (TREE_TYPE (decl)) != BLKmode + && !(flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl))); + + decl = SSA_NAME_VAR (decl); + } + if (!targetm.calls.allocate_stack_slots_for_args ()) return true; @@ -2240,7 +2269,7 @@ assign_parms_initialize_all (struct assign_parm_data_all *all) needed, else the old list. */ static void -split_complex_args (vec<tree> *args) +split_complex_args (struct assign_parm_data_all *all, vec<tree> *args) { unsigned i; tree p; @@ -2251,6 +2280,7 @@ split_complex_args (vec<tree> *args) if (TREE_CODE (type) == COMPLEX_TYPE && targetm.calls.split_complex_arg (type)) { + tree cparm = p; tree decl; tree subtype = TREE_TYPE (type); bool addressable = TREE_ADDRESSABLE (p); @@ -2269,6 +2299,9 @@ split_complex_args (vec<tree> *args) DECL_ARTIFICIAL (p) = addressable; DECL_IGNORED_P (p) = addressable; TREE_ADDRESSABLE (p) = 0; + /* Reset the RTL before layout_decl, or it may change the + mode of the RTL of the original argument copied to P. */ + SET_DECL_RTL (p, NULL_RTX); layout_decl (p, 0); (*args)[i] = p; @@ -2280,6 +2313,25 @@ split_complex_args (vec<tree> *args) DECL_IGNORED_P (decl) = addressable; layout_decl (decl, 0); args->safe_insert (++i, decl); + + /* If we are expanding a function, rather than gimplifying + it, propagate the RTL of the complex parm to the split + declarations, and set their contexts so that + maybe_reset_rtl_for_parm can recognize them and refrain + from resetting their RTL. */ + if (currently_expanding_to_rtl) + { + rtx rtl = rtl_for_parm (all, cparm); + gcc_assert (!rtl || GET_CODE (rtl) == CONCAT); + if (rtl) + { + SET_DECL_RTL (p, XEXP (rtl, 0)); + SET_DECL_RTL (decl, XEXP (rtl, 1)); + + DECL_CONTEXT (p) = cparm; + DECL_CONTEXT (decl) = cparm; + } + } } } } @@ -2342,7 +2394,7 @@ assign_parms_augmented_arg_list (struct assign_parm_data_all *all) /* If the target wants to split complex arguments into scalars, do so. */ if (targetm.calls.split_complex_arg) - split_complex_args (&fnargs); + split_complex_args (all, &fnargs); return fnargs; } @@ -2745,23 +2797,98 @@ assign_parm_remove_parallels (struct assign_parm_data_one *data) data->entry_parm = entry_parm; } +/* Wrapper for use_register_for_decl, that special-cases the + .result_ptr as the function's RESULT_DECL when the RESULT_DECL is + passed by reference. */ + +static bool +use_register_for_parm_decl (struct assign_parm_data_all *all, tree parm) +{ + if (parm == all->function_result_decl) + { + tree result = DECL_RESULT (current_function_decl); + + if (DECL_BY_REFERENCE (result)) + parm = result; + } + + return use_register_for_decl (parm); +} + +/* Wrapper for get_rtl_for_parm_ssa_default_def, that special-cases + the .result_ptr as the function's RESULT_DECL when the RESULT_DECL + is passed by reference. */ + +static rtx +rtl_for_parm (struct assign_parm_data_all *all, tree parm) +{ + if (parm == all->function_result_decl) + { + tree result = DECL_RESULT (current_function_decl); + + if (!DECL_BY_REFERENCE (result)) + return NULL_RTX; + + parm = result; + } + + return get_rtl_for_parm_ssa_default_def (parm); +} + +/* Reset the location of PARM_DECLs and RESULT_DECLs that had + SSA_NAMEs in multiple partitions, so that assign_parms will choose + the default def, if it exists, or create new RTL to hold the unused + entry value. If we are coalescing across variables, we want to + reset the location too, because a parm without a default def + (incoming value unused) might be coalesced with one with a default + def, and then assign_parms would copy both incoming values to the + same location, which might cause the wrong value to survive. */ +static void +maybe_reset_rtl_for_parm (tree parm) +{ + gcc_assert (TREE_CODE (parm) == PARM_DECL + || TREE_CODE (parm) == RESULT_DECL); + + /* This is a split complex parameter, and its context was set to its + original PARM_DECL in split_complex_args so that we could + recognize it here and not reset its RTL. */ + if (DECL_CONTEXT (parm) && TREE_CODE (DECL_CONTEXT (parm)) == PARM_DECL) + { + DECL_CONTEXT (parm) = DECL_CONTEXT (DECL_CONTEXT (parm)); + return; + } + + if ((flag_tree_coalesce_vars + || (DECL_RTL_SET_P (parm) && DECL_RTL (parm) == pc_rtx)) + && is_gimple_reg (parm)) + SET_DECL_RTL (parm, NULL_RTX); +} + /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's always valid and properly aligned. */ static void -assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data) +assign_parm_adjust_stack_rtl (struct assign_parm_data_all *all, tree parm, + struct assign_parm_data_one *data) { rtx stack_parm = data->stack_parm; + /* If out-of-SSA assigned RTL to the parm default def, make sure we + don't use what we might have computed before. */ + rtx ssa_assigned = rtl_for_parm (all, parm); + if (ssa_assigned) + stack_parm = NULL; + /* If we can't trust the parm stack slot to be aligned enough for its ultimate type, don't use that slot after entry. We'll make another stack slot, if we need one. */ - if (stack_parm - && ((STRICT_ALIGNMENT - && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm)) - || (data->nominal_type - && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm) - && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY))) + else if (stack_parm + && ((STRICT_ALIGNMENT + && (GET_MODE_ALIGNMENT (data->nominal_mode) + > MEM_ALIGN (stack_parm))) + || (data->nominal_type + && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm) + && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY))) stack_parm = NULL; /* If parm was passed in memory, and we need to convert it on entry, @@ -2823,14 +2950,21 @@ assign_parm_setup_block (struct assign_parm_data_all *all, size = int_size_in_bytes (data->passed_type); size_stored = CEIL_ROUND (size, UNITS_PER_WORD); + if (stack_parm == 0) { DECL_ALIGN (parm) = MAX (DECL_ALIGN (parm), BITS_PER_WORD); - stack_parm = assign_stack_local (BLKmode, size_stored, - DECL_ALIGN (parm)); - if (GET_MODE_SIZE (GET_MODE (entry_parm)) == size) - PUT_MODE (stack_parm, GET_MODE (entry_parm)); - set_mem_attributes (stack_parm, parm, 1); + stack_parm = rtl_for_parm (all, parm); + if (stack_parm) + stack_parm = copy_rtx (stack_parm); + else + { + stack_parm = assign_stack_local (BLKmode, size_stored, + DECL_ALIGN (parm)); + if (GET_MODE_SIZE (GET_MODE (entry_parm)) == size) + PUT_MODE (stack_parm, GET_MODE (entry_parm)); + set_mem_attributes (stack_parm, parm, 1); + } } /* If a BLKmode arrives in registers, copy it to a stack slot. Handle @@ -2968,10 +3102,19 @@ assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm, = promote_function_mode (data->nominal_type, data->nominal_mode, &unsignedp, TREE_TYPE (current_function_decl), 2); - parmreg = gen_reg_rtx (promoted_nominal_mode); + rtx from_expand = rtl_for_parm (all, parm); - if (!DECL_ARTIFICIAL (parm)) - mark_user_reg (parmreg); + if (from_expand && !data->passed_pointer) + { + parmreg = from_expand; + gcc_assert (GET_MODE (parmreg) == promoted_nominal_mode); + } + else + { + parmreg = gen_reg_rtx (promoted_nominal_mode); + if (!DECL_ARTIFICIAL (parm)) + mark_user_reg (parmreg); + } /* If this was an item that we received a pointer to, set DECL_RTL appropriately. */ @@ -2990,6 +3133,8 @@ assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm, assign_parm_find_data_types and expand_expr_real_1. */ equiv_stack_parm = data->stack_parm; + if (!equiv_stack_parm) + equiv_stack_parm = data->entry_parm; validated_mem = validize_mem (copy_rtx (data->entry_parm)); need_conversion = (data->nominal_mode != data->passed_mode @@ -3130,11 +3275,17 @@ assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm, /* If we were passed a pointer but the actual value can safely live in a register, retrieve it and use it directly. */ - if (data->passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode) + if (data->passed_pointer + && (from_expand || TYPE_MODE (TREE_TYPE (parm)) != BLKmode)) { /* We can't use nominal_mode, because it will have been set to Pmode above. We must use the actual mode of the parm. */ - if (use_register_for_decl (parm)) + if (from_expand) + { + parmreg = from_expand; + gcc_assert (GET_MODE (parmreg) == TYPE_MODE (TREE_TYPE (parm))); + } + else if (use_register_for_decl (parm)) { parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm))); mark_user_reg (parmreg); @@ -3174,7 +3325,7 @@ assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm, /* STACK_PARM is the pointer, not the parm, and PARMREG is now the parm. */ - data->stack_parm = NULL; + data->stack_parm = equiv_stack_parm = NULL; } /* Mark the register as eliminable if we did no conversion and it was @@ -3184,11 +3335,11 @@ assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm, make here would screw up life analysis for it. */ if (data->nominal_mode == data->passed_mode && !did_conversion - && data->stack_parm != 0 - && MEM_P (data->stack_parm) + && equiv_stack_parm != 0 + && MEM_P (equiv_stack_parm) && data->locate.offset.var == 0 && reg_mentioned_p (virtual_incoming_args_rtx, - XEXP (data->stack_parm, 0))) + XEXP (equiv_stack_parm, 0))) { rtx_insn *linsn = get_last_insn (); rtx_insn *sinsn; @@ -3201,8 +3352,8 @@ assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm, = GET_MODE_INNER (GET_MODE (parmreg)); int regnor = REGNO (XEXP (parmreg, 0)); int regnoi = REGNO (XEXP (parmreg, 1)); - rtx stackr = adjust_address_nv (data->stack_parm, submode, 0); - rtx stacki = adjust_address_nv (data->stack_parm, submode, + rtx stackr = adjust_address_nv (equiv_stack_parm, submode, 0); + rtx stacki = adjust_address_nv (equiv_stack_parm, submode, GET_MODE_SIZE (submode)); /* Scan backwards for the set of the real and @@ -3275,6 +3426,13 @@ assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm, if (data->stack_parm == 0) { + rtx x = data->stack_parm = rtl_for_parm (all, parm); + if (x) + gcc_assert (GET_MODE (x) == GET_MODE (data->entry_parm)); + } + + if (data->stack_parm == 0) + { int align = STACK_SLOT_ALIGNMENT (data->passed_type, GET_MODE (data->entry_parm), TYPE_ALIGN (data->passed_type)); @@ -3531,6 +3689,8 @@ assign_parms (tree fndecl) DECL_INCOMING_RTL (parm) = DECL_RTL (parm); continue; } + else + maybe_reset_rtl_for_parm (parm); /* Estimate stack alignment from parameter alignment. */ if (SUPPORTS_STACK_ALIGNMENT) @@ -3580,7 +3740,9 @@ assign_parms (tree fndecl) else set_decl_incoming_rtl (parm, data.entry_parm, false); - /* Boudns should be loaded in the particular order to + assign_parm_adjust_stack_rtl (&all, parm, &data); + + /* Bounds should be loaded in the particular order to have registers allocated correctly. Collect info about input bounds and load them later. */ if (POINTER_BOUNDS_TYPE_P (data.passed_type)) @@ -3597,11 +3759,10 @@ assign_parms (tree fndecl) } else { - assign_parm_adjust_stack_rtl (&data); - if (assign_parm_setup_block_p (&data)) assign_parm_setup_block (&all, parm, &data); - else if (data.passed_pointer || use_register_for_decl (parm)) + else if (data.passed_pointer + || use_register_for_parm_decl (&all, parm)) assign_parm_setup_reg (&all, parm, &data); else assign_parm_setup_stack (&all, parm, &data); @@ -4932,7 +5093,9 @@ expand_function_start (tree subr) before any library calls that assign parms might generate. */ /* Decide whether to return the value in memory or in a register. */ - if (aggregate_value_p (DECL_RESULT (subr), subr)) + tree res = DECL_RESULT (subr); + maybe_reset_rtl_for_parm (res); + if (aggregate_value_p (res, subr)) { /* Returning something that won't go in a register. */ rtx value_address = 0; @@ -4940,7 +5103,7 @@ expand_function_start (tree subr) #ifdef PCC_STATIC_STRUCT_RETURN if (cfun->returns_pcc_struct) { - int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr))); + int size = int_size_in_bytes (TREE_TYPE (res)); value_address = assemble_static_space (size); } else @@ -4952,36 +5115,45 @@ expand_function_start (tree subr) it. */ if (sv) { - value_address = gen_reg_rtx (Pmode); + if (DECL_BY_REFERENCE (res)) + value_address = get_rtl_for_parm_ssa_default_def (res); + if (!value_address) + value_address = gen_reg_rtx (Pmode); emit_move_insn (value_address, sv); } } if (value_address) { rtx x = value_address; - if (!DECL_BY_REFERENCE (DECL_RESULT (subr))) + if (!DECL_BY_REFERENCE (res)) { - x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), x); - set_mem_attributes (x, DECL_RESULT (subr), 1); + x = get_rtl_for_parm_ssa_default_def (res); + if (!x) + { + x = gen_rtx_MEM (DECL_MODE (res), value_address); + set_mem_attributes (x, res, 1); + } } - SET_DECL_RTL (DECL_RESULT (subr), x); + SET_DECL_RTL (res, x); } } - else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode) + else if (DECL_MODE (res) == VOIDmode) /* If return mode is void, this decl rtl should not be used. */ - SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX); + SET_DECL_RTL (res, NULL_RTX); else { /* Compute the return values into a pseudo reg, which we will copy into the true return register after the cleanups are done. */ - tree return_type = TREE_TYPE (DECL_RESULT (subr)); - if (TYPE_MODE (return_type) != BLKmode - && targetm.calls.return_in_msb (return_type)) + tree return_type = TREE_TYPE (res); + rtx x = get_rtl_for_parm_ssa_default_def (res); + if (x) + /* Use it. */; + else if (TYPE_MODE (return_type) != BLKmode + && targetm.calls.return_in_msb (return_type)) /* expand_function_end will insert the appropriate padding in this case. Use the return value's natural (unpadded) mode within the function proper. */ - SET_DECL_RTL (DECL_RESULT (subr), - gen_reg_rtx (TYPE_MODE (return_type))); + x = gen_reg_rtx (TYPE_MODE (return_type)); else { /* In order to figure out what mode to use for the pseudo, we @@ -4992,25 +5164,26 @@ expand_function_start (tree subr) /* Structures that are returned in registers are not aggregate_value_p, so we may see a PARALLEL or a REG. */ if (REG_P (hard_reg)) - SET_DECL_RTL (DECL_RESULT (subr), - gen_reg_rtx (GET_MODE (hard_reg))); + x = gen_reg_rtx (GET_MODE (hard_reg)); else { gcc_assert (GET_CODE (hard_reg) == PARALLEL); - SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg)); + x = gen_group_rtx (hard_reg); } } + SET_DECL_RTL (res, x); + /* Set DECL_REGISTER flag so that expand_function_end will copy the result to the real return register(s). */ - DECL_REGISTER (DECL_RESULT (subr)) = 1; + DECL_REGISTER (res) = 1; if (chkp_function_instrumented_p (current_function_decl)) { - tree return_type = TREE_TYPE (DECL_RESULT (subr)); + tree return_type = TREE_TYPE (res); rtx bounds = targetm.calls.chkp_function_value_bounds (return_type, subr, 1); - SET_DECL_BOUNDS_RTL (DECL_RESULT (subr), bounds); + SET_DECL_BOUNDS_RTL (res, bounds); } } @@ -5025,7 +5198,9 @@ expand_function_start (tree subr) rtx local, chain; rtx_insn *insn; - local = gen_reg_rtx (Pmode); + local = get_rtl_for_parm_ssa_default_def (parm); + if (!local) + local = gen_reg_rtx (Pmode); chain = targetm.calls.static_chain (current_function_decl, true); set_decl_incoming_rtl (parm, chain, false); |