src/mesa/drivers/dri/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_dataflow.h"
  36 #include "radeon_program.h"
  37
  38 /**
  39  * This function renames registers in an attempt to get the code close to
  40  * SSA form.  After this function has completed, most of the register are only
  41  * written to one time, with a few exceptions.
  42  *
  43  * This function assumes all the instructions are still of type
  44  * RC_INSTRUCTION_NORMAL.
  45  */
  46 void rc_rename_regs(struct radeon_compiler *c, void *user)
  47 {
  48         unsigned int i, used_length;
  49         int new_index;
  50         struct rc_instruction * inst;
  51         struct rc_reader_data reader_data;
  52         unsigned char * used;
  53
  54         /* XXX Remove this once the register allocation works with flow control. */
  55         for(inst = c->Program.Instructions.Next;
  56                                         inst != &c->Program.Instructions;
  57                                         inst = inst->Next) {
  58                 if (inst->U.I.Opcode == RC_OPCODE_BGNLOOP)
  59                         return;
  60         }
  61
  62         used_length = 2 * rc_recompute_ips(c);
  63         used = memory_pool_malloc(&c->Pool, sizeof(unsigned char) * used_length);
  64         memset(used, 0, sizeof(unsigned char) * used_length);
  65
  66         rc_get_used_temporaries(c, used, used_length);
  67         for(inst = c->Program.Instructions.Next;
  68                                         inst != &c->Program.Instructions;
  69                                         inst = inst->Next) {
  70
  71                 if (inst->U.I.DstReg.File != RC_FILE_TEMPORARY)
  72                         continue;
  73
  74                 rc_get_readers(c, inst, &reader_data, NULL, NULL, NULL);
  75
  76                 if (reader_data.Abort || reader_data.ReaderCount == 0)
  77                         continue;
  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                 reader_data.Writer->U.I.DstReg.Index = new_index;
  87                 for(i = 0; i < reader_data.ReaderCount; i++) {
  88                         reader_data.Readers[i].U.Src->Index = new_index;
  89                 }
  90         }
  91 }