2 * Copyright © 2014 Broadcom
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
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,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
25 * @file vc4_opt_small_immediates.c
27 * Turns references to small constant uniform values into small immediates
37 qir_opt_small_immediates(struct vc4_compile
*c
)
39 bool progress
= false;
41 qir_for_each_inst_inorder(inst
, c
) {
42 /* The small immediate value sits in the raddr B field, so we
43 * can't have 2 small immediates in one instruction (unless
44 * they're the same value, but that should be optimized away
47 bool uses_small_imm
= false;
48 for (int i
= 0; i
< qir_get_nsrc(inst
); i
++) {
49 if (inst
->src
[i
].file
== QFILE_SMALL_IMM
)
50 uses_small_imm
= true;
55 /* Don't propagate small immediates into the top-end bounds
56 * checking for indirect UBO loads. The kernel doesn't parse
57 * small immediates and rejects the shader in this case. UBO
58 * loads are much more expensive than the uniform load, and
59 * indirect UBO regions are usually much larger than a small
60 * immediate, so it's not worth updating the kernel to allow
63 if (inst
->op
== QOP_MIN_NOIMM
)
66 for (int i
= 0; i
< qir_get_nsrc(inst
); i
++) {
67 struct qreg src
= qir_follow_movs(c
, inst
->src
[i
]);
69 if (src
.file
!= QFILE_UNIF
||
71 c
->uniform_contents
[src
.index
] !=
76 if (qir_is_tex(inst
) &&
77 i
== qir_get_tex_uniform_src(inst
)) {
78 /* No turning the implicit uniform read into
84 uint32_t imm
= c
->uniform_data
[src
.index
];
85 uint32_t small_imm
= qpu_encode_small_immediate(imm
);
90 fprintf(stderr
, "opt_small_immediate() from: ");
91 qir_dump_inst(c
, inst
);
92 fprintf(stderr
, "\n");
94 inst
->src
[i
].file
= QFILE_SMALL_IMM
;
95 inst
->src
[i
].index
= imm
;
97 fprintf(stderr
, "to: ");
98 qir_dump_inst(c
, inst
);
99 fprintf(stderr
, "\n");