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11 * The above copyright notice and this permission notice (including the next
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16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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25 #include "brw_fs_live_variables.h"
28 /** @file brw_fs_saturate_propagation.cpp
30 * Implements a pass that propagates the SAT modifier from a MOV.SAT into the
31 * instruction that produced the source of the MOV.SAT, thereby allowing the
32 * MOV's src and dst to be coalesced and the MOV removed.
39 * would be transformed into
41 * ADD.SAT tmp, src0, src1
46 opt_saturate_propagation_local(fs_visitor
*v
, bblock_t
*block
)
48 bool progress
= false;
49 int ip
= block
->end_ip
+ 1;
51 foreach_inst_in_block_reverse(fs_inst
, inst
, block
) {
54 if (inst
->opcode
!= BRW_OPCODE_MOV
||
56 inst
->dst
.file
!= VGRF
||
57 inst
->dst
.type
!= inst
->src
[0].type
||
58 inst
->src
[0].file
!= VGRF
||
62 int src_var
= v
->live_intervals
->var_from_reg(inst
->src
[0]);
63 int src_end_ip
= v
->live_intervals
->end
[src_var
];
65 bool interfered
= false;
66 foreach_inst_in_block_reverse_starting_from(fs_inst
, scan_inst
, inst
) {
67 if (regions_overlap(scan_inst
->dst
, scan_inst
->size_written
,
68 inst
->src
[0], inst
->size_read(0))) {
69 if (scan_inst
->is_partial_write() ||
70 (scan_inst
->dst
.type
!= inst
->dst
.type
&&
71 !scan_inst
->can_change_types()))
74 if (scan_inst
->saturate
) {
75 inst
->saturate
= false;
77 } else if (src_end_ip
== ip
|| inst
->dst
.equals(inst
->src
[0])) {
78 if (scan_inst
->can_do_saturate()) {
79 if (scan_inst
->dst
.type
!= inst
->dst
.type
) {
80 scan_inst
->dst
.type
= inst
->dst
.type
;
81 for (int i
= 0; i
< scan_inst
->sources
; i
++) {
82 scan_inst
->src
[i
].type
= inst
->dst
.type
;
86 if (inst
->src
[0].negate
) {
87 if (scan_inst
->opcode
== BRW_OPCODE_MUL
) {
88 scan_inst
->src
[0].negate
= !scan_inst
->src
[0].negate
;
89 inst
->src
[0].negate
= false;
90 } else if (scan_inst
->opcode
== BRW_OPCODE_MAD
) {
91 scan_inst
->src
[0].negate
= !scan_inst
->src
[0].negate
;
92 scan_inst
->src
[1].negate
= !scan_inst
->src
[1].negate
;
93 inst
->src
[0].negate
= false;
94 } else if (scan_inst
->opcode
== BRW_OPCODE_ADD
) {
95 if (scan_inst
->src
[1].file
== IMM
) {
96 if (!brw_negate_immediate(scan_inst
->src
[1].type
,
97 &scan_inst
->src
[1].as_brw_reg())) {
101 scan_inst
->src
[1].negate
= !scan_inst
->src
[1].negate
;
103 scan_inst
->src
[0].negate
= !scan_inst
->src
[0].negate
;
104 inst
->src
[0].negate
= false;
110 scan_inst
->saturate
= true;
111 inst
->saturate
= false;
117 for (int i
= 0; i
< scan_inst
->sources
; i
++) {
118 if (scan_inst
->src
[i
].file
== VGRF
&&
119 scan_inst
->src
[i
].nr
== inst
->src
[0].nr
&&
120 scan_inst
->src
[i
].offset
/ REG_SIZE
==
121 inst
->src
[0].offset
/ REG_SIZE
) {
122 if (scan_inst
->opcode
!= BRW_OPCODE_MOV
||
123 !scan_inst
->saturate
||
124 scan_inst
->src
[0].abs
||
125 scan_inst
->src
[0].negate
||
126 scan_inst
->src
[0].abs
!= inst
->src
[0].abs
||
127 scan_inst
->src
[0].negate
!= inst
->src
[0].negate
) {
143 fs_visitor::opt_saturate_propagation()
145 bool progress
= false;
147 calculate_live_intervals();
149 foreach_block (block
, cfg
) {
150 progress
= opt_saturate_propagation_local(this, block
) || progress
;
153 /* Live intervals are still valid. */