src/gallium/drivers/r300/compiler/radeon_rename_regs.c

   1 /*
   2  * Copyright 2010 Tom Stellard <tstellar@gmail.com>
   3  *
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining
   7  * a copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sublicense, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial
  16  * portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  19  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  21  * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
  22  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  23  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  24  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  */
  27
  28 /**
  29  * \file
  30  */
  31
  32 #include "radeon_rename_regs.h"
  33
  34 #include "radeon_compiler.h"
  35 #include "radeon_list.h"
  36 #include "radeon_program.h"
  37 #include "radeon_variable.h"
  38
  39 /**
  40  * This function renames registers in an attempt to get the code close to
  41  * SSA form.  After this function has completed, most of the register are only
  42  * written to one time, with a few exceptions.
  43  *
  44  * This function assumes all the instructions are still of type
  45  * RC_INSTRUCTION_NORMAL.
  46  */
  47 void rc_rename_regs(struct radeon_compiler *c, void *user)
  48 {
  49         unsigned int used_length;
  50         struct rc_instruction * inst;
  51         unsigned char * used;
  52         struct rc_list * variables;
  53         struct rc_list * var_ptr;
  54
  55         /* XXX Remove this once the register allocation works with flow control. */
  56         for(inst = c->Program.Instructions.Next;
  57                                         inst != &c->Program.Instructions;
  58                                         inst = inst->Next) {
  59                 if (inst->U.I.Opcode == RC_OPCODE_BGNLOOP)
  60                         return;
  61         }
  62
  63         used_length = 2 * rc_recompute_ips(c);
  64         used = memory_pool_malloc(&c->Pool, sizeof(unsigned char) * used_length);
  65         memset(used, 0, sizeof(unsigned char) * used_length);
  66
  67         rc_get_used_temporaries(c, used, used_length);
  68         variables = rc_get_variables(c);
  69
  70         for (var_ptr = variables; var_ptr; var_ptr = var_ptr->Next) {
  71                 int new_index;
  72                 unsigned writemask;
  73                 struct rc_variable * var = var_ptr->Item;
  74
  75                 if (var->Inst->U.I.DstReg.File != RC_FILE_TEMPORARY) {
  76                         continue;
  77                 }
  78
  79                 new_index = rc_find_free_temporary_list(c, used, used_length,
  80                                                 RC_MASK_XYZW);
  81                 if (new_index < 0) {
  82                         rc_error(c, "Ran out of temporary registers\n");
  83                         return;
  84                 }
  85
  86                 writemask = rc_variable_writemask_sum(var);
  87                 rc_variable_change_dst(var, new_index, writemask);
  88         }
  89 }