nsz Git - libfirm/blob - ir/be/sparc/sparc_stackframe.c

   1 /*
   2  * Copyright (C) 1995-2010 University of Karlsruhe.  All right reserved.
   3  *
   4  * This file is part of libFirm.
   5  *
   6  * This file may be distributed and/or modified under the terms of the
   7  * GNU General Public License version 2 as published by the Free Software
   8  * Foundation and appearing in the file LICENSE.GPL included in the
   9  * packaging of this file.
  10  *
  11  * Licensees holding valid libFirm Professional Edition licenses may use
  12  * this file in accordance with the libFirm Commercial License.
  13  * Agreement provided with the Software.
  14  *
  15  * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
  16  * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE.
  18  */
  19
  20 /**
  21  * @file
  22  * @brief   Manage addressing into the stackframe
  23  * @author  Matthias Braun
  24  */
  25 #include "config.h"
  26
  27 #include "beirg.h"
  28 #include "error.h"
  29 #include "firm_types.h"
  30 #include "irnode_t.h"
  31 #include "bearch_sparc_t.h"
  32 #include "sparc_new_nodes.h"
  33 #include "sparc_cconv.h"
  34 #include "bitfiddle.h"
  35 #include "bearch.h"
  36 #include "benode.h"
  37 #include "besched.h"
  38
  39 static void set_irn_sp_bias(ir_node *node, int new_bias)
  40 {
  41         if (be_is_IncSP(node)) {
  42                 be_set_IncSP_offset(node, new_bias);
  43         } else if (is_sparc_Save(node)) {
  44                 sparc_attr_t *attr = get_sparc_attr(node);
  45                 attr->immediate_value = -new_bias;
  46         } else if (is_sparc_Restore(node)) {
  47                 sparc_attr_t *attr = get_sparc_attr(node);
  48                 attr->immediate_value = new_bias;
  49         }
  50 }
  51
  52 static void process_bias(ir_node *block, bool sp_relative, int bias,
  53                          int free_bytes)
  54 {
  55         mark_Block_block_visited(block);
  56
  57         /* process schedule */
  58         sched_foreach(block, irn) {
  59                 int irn_bias;
  60
  61                 /* set bias to nodes with entities */
  62                 ir_entity *entity = arch_get_frame_entity(irn);
  63                 if (entity != NULL) {
  64                         int offset = get_entity_offset(entity);
  65                         if (sp_relative)
  66                                 offset += bias + SPARC_MIN_STACKSIZE;
  67                         arch_set_frame_offset(irn, offset);
  68                 }
  69
  70                 /* The additional alignment bytes cannot be used
  71                  * anymore after alloca. */
  72                 if (is_sparc_SubSP(irn)) {
  73                         free_bytes = 0;
  74                 } else if (is_sparc_AddSP(irn)) {
  75                         assert(free_bytes == 0);
  76                 }
  77
  78                 irn_bias = arch_get_sp_bias(irn);
  79                 if (irn_bias == 0) {
  80                         /* do nothing */
  81                 } else if (irn_bias == SP_BIAS_RESET) {
  82                         bias = 0;
  83                 } else {
  84                         /* adjust values to respect stack alignment */
  85                         int new_bias_unaligned;
  86                         int new_bias_aligned;
  87                         irn_bias -= free_bytes;
  88
  89                         new_bias_unaligned = bias + irn_bias;
  90                         new_bias_aligned
  91                                 = round_up2(new_bias_unaligned, SPARC_STACK_ALIGNMENT);
  92                         free_bytes = new_bias_aligned - new_bias_unaligned;
  93                         set_irn_sp_bias(irn, new_bias_aligned - bias);
  94                         bias = new_bias_aligned;
  95                 }
  96         }
  97
  98 #ifndef NDEBUG
  99         if (block == get_irg_end_block(get_irn_irg(block))) {
 100                 assert(bias == 0);
 101         }
 102 #endif
 103
 104         /* continue at the successor blocks */
 105         foreach_block_succ(block, edge) {
 106                 ir_node *succ = get_edge_src_irn(edge);
 107                 if (Block_block_visited(succ))
 108                         continue;
 109                 process_bias(succ, sp_relative, bias, free_bytes);
 110         }
 111 }
 112
 113 static void adjust_entity_offsets(ir_type *type, long offset)
 114 {
 115         size_t n_members = get_compound_n_members(type);
 116         size_t i;
 117
 118         for (i = 0; i < n_members; ++i) {
 119                 ir_entity *member        = get_compound_member(type, i);
 120                 int        member_offset = get_entity_offset(member);
 121                 set_entity_offset(member, member_offset + offset);
 122         }
 123 }
 124
 125 /**
 126  * Perform some fixups for variadic functions.
 127  * To make the rest of the frontend code easier to understand we add
 128  * "dummy" parameters until the number of parameters transmitted in registers.
 129  * (because otherwise the backend wouldn't store the value of the register
 130  *  parameters into memory for the VLA magic)
 131  */
 132 bool sparc_variadic_fixups(ir_graph *irg, calling_convention_t *cconv)
 133 {
 134         ir_entity *entity = get_irg_entity(irg);
 135         ir_type   *mtp    = get_entity_type(entity);
 136         if (get_method_variadicity(mtp) != variadicity_variadic)
 137                 return false;
 138
 139         if (cconv->n_param_regs >= SPARC_N_PARAM_REGS)
 140                 return false;
 141
 142         {
 143         size_t         n_params     = get_method_n_params(mtp);
 144         type_dbg_info *dbgi         = get_type_dbg_info(mtp);
 145         size_t         n_ress       = get_method_n_ress(mtp);
 146         size_t         new_n_params
 147                 = n_params + (SPARC_N_PARAM_REGS - cconv->n_param_regs);
 148         ir_type       *new_mtp      = new_d_type_method(new_n_params, n_ress, dbgi);
 149         ir_mode       *gp_reg_mode  = sparc_reg_classes[CLASS_sparc_gp].mode;
 150         ir_type       *gp_reg_type  = get_type_for_mode(gp_reg_mode);
 151         ir_type       *frame_type   = get_irg_frame_type(irg);
 152         size_t         i;
 153
 154         for (i = 0; i < n_ress; ++i) {
 155                 ir_type *type = get_method_res_type(mtp, i);
 156                 set_method_res_type(new_mtp, i, type);
 157         }
 158         for (i = 0; i < n_params; ++i) {
 159                 ir_type *type = get_method_param_type(mtp, i);
 160                 set_method_param_type(new_mtp, i, type);
 161         }
 162         for ( ; i < new_n_params; ++i) {
 163                 set_method_param_type(new_mtp, i, gp_reg_type);
 164                 new_parameter_entity(frame_type, i, gp_reg_type);
 165         }
 166
 167         set_method_variadicity(new_mtp, get_method_variadicity(mtp));
 168         set_method_calling_convention(new_mtp, get_method_calling_convention(mtp));
 169         set_method_additional_properties(new_mtp, get_method_additional_properties(mtp));
 170         set_higher_type(new_mtp, mtp);
 171
 172         set_entity_type(entity, new_mtp);
 173         }
 174         return true;
 175 }
 176
 177 static ir_type *compute_arg_type(ir_graph *irg, calling_convention_t *cconv,
 178                                  ir_type *between_type)
 179 {
 180         ir_entity       *va_start_entity = NULL;
 181         const ir_entity *entity          = get_irg_entity(irg);
 182         const ir_type   *mtp             = get_entity_type(entity);
 183         size_t           n_params        = get_method_n_params(mtp);
 184         ir_entity      **param_map       = ALLOCANZ(ir_entity*, n_params);
 185
 186         ir_type *frame_type      = get_irg_frame_type(irg);
 187         size_t   n_frame_members = get_compound_n_members(frame_type);
 188         size_t   f;
 189         size_t   i;
 190
 191         ir_type *res = new_type_struct(id_mangle_u(get_entity_ident(entity), new_id_from_chars("arg_type", 8)));
 192
 193         /* search for existing value_param entities */
 194         for (f = n_frame_members; f > 0; ) {
 195                 ir_entity *member = get_compound_member(frame_type, --f);
 196                 size_t     num;
 197
 198                 if (!is_parameter_entity(member))
 199                         continue;
 200                 num = get_entity_parameter_number(member);
 201                 if (num == IR_VA_START_PARAMETER_NUMBER) {
 202                         if (va_start_entity != NULL)
 203                                 panic("multiple va_start entities found (%+F,%+F)",
 204                                       va_start_entity, member);
 205                         va_start_entity = member;
 206                         continue;
 207                 }
 208                 assert(num < n_params);
 209                 if (param_map[num] != NULL)
 210                         panic("multiple entities for parameter %u in %+F found", f, irg);
 211
 212                 param_map[num] = member;
 213                 /* move to new arg_type */
 214                 set_entity_owner(member, res);
 215         }
 216
 217         /* calculate offsets/create missing entities */
 218         for (i = 0; i < n_params; ++i) {
 219                 reg_or_stackslot_t *param  = &cconv->parameters[i];
 220                 ir_entity          *entity = param_map[i];
 221
 222                 if (param->reg0 != NULL) {
 223                         /* use reserved spill space on between type */
 224                         if (entity != NULL) {
 225                                 long offset = SPARC_PARAMS_SPILL_OFFSET + i * SPARC_REGISTER_SIZE;
 226                                 assert(i < SPARC_N_PARAM_REGS);
 227                                 set_entity_owner(entity, between_type);
 228                                 set_entity_offset(entity, offset);
 229                         }
 230                         continue;
 231                 }
 232
 233                 if (entity == NULL)
 234                         entity = new_parameter_entity(res, i, param->type);
 235                 param->entity = entity;
 236                 set_entity_offset(entity, param->offset);
 237         }
 238
 239         if (va_start_entity != NULL) {
 240                 /* sparc_variadic_fixups() fiddled with our type, find out the
 241                  * original number of parameters */
 242                 ir_type *non_lowered   = get_higher_type(mtp);
 243                 size_t   orig_n_params = get_method_n_params(non_lowered);
 244                 long     offset;
 245                 assert(get_method_variadicity(mtp) == variadicity_variadic);
 246                 if (orig_n_params < n_params) {
 247                         assert(param_map[orig_n_params] != NULL);
 248                         offset = get_entity_offset(param_map[orig_n_params]);
 249                         set_entity_owner(va_start_entity, between_type);
 250                         set_entity_offset(va_start_entity, offset);
 251                 } else {
 252                         set_entity_owner(va_start_entity, res);
 253                         set_entity_offset(va_start_entity, cconv->param_stack_size);
 254                 }
 255         }
 256         set_type_size_bytes(res, cconv->param_stack_size);
 257
 258         return res;
 259 }
 260
 261 void sparc_create_stacklayout(ir_graph *irg, calling_convention_t *cconv)
 262 {
 263         be_stack_layout_t *layout = be_get_irg_stack_layout(irg);
 264         ir_type           *between_type;
 265         memset(layout, 0, sizeof(*layout));
 266
 267         between_type = new_type_class(new_id_from_str("sparc_between_type"));
 268         if (cconv->omit_fp) {
 269                 set_type_size_bytes(between_type, 0);
 270         } else {
 271                 set_type_size_bytes(between_type, SPARC_MIN_STACKSIZE);
 272         }
 273
 274         layout->frame_type     = get_irg_frame_type(irg);
 275         layout->between_type   = between_type;
 276         layout->arg_type       = compute_arg_type(irg, cconv, between_type);
 277         layout->initial_offset = 0;
 278         layout->initial_bias   = 0;
 279         layout->sp_relative    = cconv->omit_fp;
 280
 281         assert(N_FRAME_TYPES == 3);
 282         layout->order[0] = layout->frame_type;
 283         layout->order[1] = layout->between_type;
 284         layout->order[2] = layout->arg_type;
 285 }
 286
 287 /* Assign entity offsets, to all stack-related entities.
 288  * The offsets are relative to the begin of the stack frame.
 289  */
 290 void sparc_adjust_stack_entity_offsets(ir_graph *irg)
 291 {
 292         be_stack_layout_t *layout = be_get_irg_stack_layout(irg);
 293
 294         /* initially the stackpointer points to the begin of our stackframe.
 295          * Situation at the begin of our function:
 296          *
 297          *      high address |-----------------------------|
 298          *                   |            ...              |
 299          *          arg-type |         stackarg 1          |
 300          *                   |         stackarg 0          |
 301          *                   |-----------------------------|
 302          *                   | space for storing regarg0-5 |
 303          *      between type | pointer to aggregate return |
 304          *                   |      16 words save are      |
 305          *  stack pointer -> |-----------------------------|
 306          *                   |    high end of stackframe   |
 307          *                   |            ...              |
 308          *                   |    low end of stackframe    |
 309          *      low address  |-----------------------------|
 310          */
 311         ir_type *between_type = layout->between_type;
 312         unsigned between_size = get_type_size_bytes(between_type);
 313
 314         ir_type *frame_type  = get_irg_frame_type(irg);
 315         unsigned frame_size  = get_type_size_bytes(frame_type);
 316         unsigned frame_align = get_type_alignment_bytes(frame_type);
 317
 318         /* There's the tricky case of the stackframe size not being a multiple
 319          * of the alignment. There are 2 variants:
 320          *
 321          * - frame-pointer relative addressing:
 322          *   Increase frame_size in case it is not a multiple of the alignment as we
 323          *   address entities from the "top" with negative offsets
 324          * - stack-pointer relative addressing:
 325          *   Stackframesize + SPARC_MIN_STACK_SIZE has to be aligned. Increase
 326          *   frame_size accordingly.
 327          */
 328         if (!layout->sp_relative) {
 329                 frame_size = (frame_size + frame_align-1) & ~(frame_align-1);
 330         } else {
 331                 unsigned misalign = (SPARC_MIN_STACKSIZE+frame_size) % frame_align;
 332                 frame_size += misalign;
 333         }
 334         set_type_size_bytes(frame_type, frame_size);
 335
 336         ir_type *arg_type = layout->arg_type;
 337
 338         adjust_entity_offsets(frame_type, -(long)frame_size);
 339         /* no need to adjust between type, it's already at 0 */
 340         adjust_entity_offsets(arg_type, between_size);
 341 }
 342
 343 void sparc_fix_stack_bias(ir_graph *irg)
 344 {
 345         bool sp_relative = be_get_irg_stack_layout(irg)->sp_relative;
 346
 347         ir_node *start_block = get_irg_start_block(irg);
 348
 349         ir_reserve_resources(irg, IR_RESOURCE_BLOCK_VISITED);
 350         inc_irg_block_visited(irg);
 351         process_bias(start_block, sp_relative, 0, 0);
 352         ir_free_resources(irg, IR_RESOURCE_BLOCK_VISITED);
 353 }