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      1 /*
      2  * Copyright 2010 Tom Stellard <tstellar (at) 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 		unsigned 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 }
     90