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