2 * Copyright © 2014 Broadcom
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5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
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11 * The above copyright notice and this permission notice (including the next
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15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
27 * This modifies instructions that exclusively consume a value read from the
28 * VPM to directly read the VPM if other operands allow it.
34 qir_opt_vpm(struct vc4_compile
*c
)
36 if (c
->stage
== QSTAGE_FRAG
)
39 /* For now, only do this pass when we don't have control flow. */
40 struct qblock
*block
= qir_entry_block(c
);
41 if (block
!= qir_exit_block(c
))
44 bool progress
= false;
45 uint32_t use_count
[c
->num_temps
];
46 memset(&use_count
, 0, sizeof(use_count
));
48 qir_for_each_inst_inorder(inst
, c
) {
49 for (int i
= 0; i
< qir_get_nsrc(inst
); i
++) {
50 if (inst
->src
[i
].file
== QFILE_TEMP
) {
51 uint32_t temp
= inst
->src
[i
].index
;
57 /* For instructions reading from a temporary that contains a VPM read
58 * result, try to move the instruction up in place of the VPM read.
60 qir_for_each_inst_inorder(inst
, c
) {
64 if (qir_depends_on_flags(inst
) || inst
->sf
)
67 if (qir_has_side_effects(c
, inst
) ||
68 qir_has_side_effect_reads(c
, inst
) ||
72 for (int j
= 0; j
< qir_get_nsrc(inst
); j
++) {
73 if (inst
->src
[j
].file
!= QFILE_TEMP
||
77 uint32_t temp
= inst
->src
[j
].index
;
79 /* Since VPM reads pull from a FIFO, we only get to
80 * read each VPM entry once (unless we reset the read
81 * pointer). That means we can't copy-propagate a VPM
82 * read to multiple locations.
84 if (use_count
[temp
] != 1)
87 struct qinst
*mov
= c
->defs
[temp
];
89 (mov
->op
!= QOP_MOV
&&
90 mov
->op
!= QOP_FMOV
&&
91 mov
->op
!= QOP_MMOV
) ||
92 mov
->src
[0].file
!= QFILE_VPM
) {
97 for (int k
= 0; k
< qir_get_nsrc(inst
); k
++) {
98 if (inst
->src
[k
].file
== QFILE_TEMP
)
102 /* The instruction is safe to reorder if its other
103 * sources are independent of previous instructions
106 inst
->src
[j
] = mov
->src
[0];
108 list_del(&inst
->link
);
109 list_addtail(&inst
->link
, &mov
->link
);
110 qir_remove_instruction(c
, mov
);