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  */
rc_rename_regs(struct radeon_compiler * c,void * user)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