2 * Copyright (C) 2018 Alyssa Rosenzweig <alyssa@rosenzweig.io>
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 FROM,
20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
24 #include <sys/types.h>
33 #include "main/mtypes.h"
34 #include "compiler/glsl/glsl_to_nir.h"
35 #include "compiler/nir_types.h"
36 #include "main/imports.h"
37 #include "compiler/nir/nir_builder.h"
38 #include "util/half_float.h"
39 #include "util/register_allocate.h"
40 #include "util/u_debug.h"
41 #include "util/u_dynarray.h"
42 #include "util/list.h"
43 #include "main/mtypes.h"
46 #include "midgard_nir.h"
47 #include "midgard_compile.h"
50 #include "disassemble.h"
52 static const struct debug_named_value debug_options
[] = {
53 {"msgs", MIDGARD_DBG_MSGS
, "Print debug messages"},
54 {"shaders", MIDGARD_DBG_SHADERS
, "Dump shaders in NIR and MIR"},
58 DEBUG_GET_ONCE_FLAGS_OPTION(midgard_debug
, "MIDGARD_MESA_DEBUG", debug_options
, 0)
60 int midgard_debug
= 0;
62 #define DBG(fmt, ...) \
63 do { if (midgard_debug & MIDGARD_DBG_MSGS) \
64 fprintf(stderr, "%s:%d: "fmt, \
65 __FUNCTION__, __LINE__, ##__VA_ARGS__); } while (0)
67 /* Instruction arguments represented as block-local SSA indices, rather than
68 * registers. Negative values mean unused. */
75 /* src1 is -not- SSA but instead a 16-bit inline constant to be smudged
76 * in. Only valid for ALU ops. */
80 /* Forward declare so midgard_branch can reference */
83 /* Target types. Defaults to TARGET_GOTO (the type corresponding directly to
84 * the hardware), hence why that must be zero. TARGET_DISCARD signals this
85 * instruction is actually a discard op. */
88 #define TARGET_BREAK 1
89 #define TARGET_CONTINUE 2
90 #define TARGET_DISCARD 3
92 typedef struct midgard_branch
{
93 /* If conditional, the condition is specified in r31.w */
96 /* For conditionals, if this is true, we branch on FALSE. If false, we branch on TRUE. */
97 bool invert_conditional
;
99 /* Branch targets: the start of a block, the start of a loop (continue), the end of a loop (break). Value is one of TARGET_ */
100 unsigned target_type
;
102 /* The actual target */
110 /* Generic in-memory data type repesenting a single logical instruction, rather
111 * than a single instruction group. This is the preferred form for code gen.
112 * Multiple midgard_insturctions will later be combined during scheduling,
113 * though this is not represented in this structure. Its format bridges
114 * the low-level binary representation with the higher level semantic meaning.
116 * Notably, it allows registers to be specified as block local SSA, for code
117 * emitted before the register allocation pass.
120 typedef struct midgard_instruction
{
121 /* Must be first for casting */
122 struct list_head link
;
124 unsigned type
; /* ALU, load/store, texture */
126 /* If the register allocator has not run yet... */
129 /* Special fields for an ALU instruction */
130 midgard_reg_info registers
;
132 /* I.e. (1 << alu_bit) */
137 uint16_t inline_constant
;
138 bool has_blend_constant
;
142 bool prepacked_branch
;
145 midgard_load_store_word load_store
;
146 midgard_vector_alu alu
;
147 midgard_texture_word texture
;
148 midgard_branch_extended branch_extended
;
151 /* General branch, rather than packed br_compact. Higher level
152 * than the other components */
153 midgard_branch branch
;
155 } midgard_instruction
;
157 typedef struct midgard_block
{
158 /* Link to next block. Must be first for mir_get_block */
159 struct list_head link
;
161 /* List of midgard_instructions emitted for the current block */
162 struct list_head instructions
;
166 /* List of midgard_bundles emitted (after the scheduler has run) */
167 struct util_dynarray bundles
;
169 /* Number of quadwords _actually_ emitted, as determined after scheduling */
170 unsigned quadword_count
;
172 struct midgard_block
*next_fallthrough
;
175 /* Helpers to generate midgard_instruction's using macro magic, since every
176 * driver seems to do it that way */
178 #define EMIT(op, ...) emit_mir_instruction(ctx, v_##op(__VA_ARGS__));
180 #define M_LOAD_STORE(name, rname, uname) \
181 static midgard_instruction m_##name(unsigned ssa, unsigned address) { \
182 midgard_instruction i = { \
183 .type = TAG_LOAD_STORE_4, \
190 .op = midgard_op_##name, \
192 .swizzle = SWIZZLE(COMPONENT_X, COMPONENT_Y, COMPONENT_Z, COMPONENT_W), \
200 #define M_LOAD(name) M_LOAD_STORE(name, dest, src0)
201 #define M_STORE(name) M_LOAD_STORE(name, src0, dest)
203 const midgard_vector_alu_src blank_alu_src
= {
204 .swizzle
= SWIZZLE(COMPONENT_X
, COMPONENT_Y
, COMPONENT_Z
, COMPONENT_W
),
207 const midgard_vector_alu_src blank_alu_src_xxxx
= {
208 .swizzle
= SWIZZLE(COMPONENT_X
, COMPONENT_X
, COMPONENT_X
, COMPONENT_X
),
211 const midgard_scalar_alu_src blank_scalar_alu_src
= {
215 /* Used for encoding the unused source of 1-op instructions */
216 const midgard_vector_alu_src zero_alu_src
= { 0 };
218 /* Coerce structs to integer */
221 vector_alu_srco_unsigned(midgard_vector_alu_src src
)
224 memcpy(&u
, &src
, sizeof(src
));
228 /* Inputs a NIR ALU source, with modifiers attached if necessary, and outputs
229 * the corresponding Midgard source */
231 static midgard_vector_alu_src
232 vector_alu_modifiers(nir_alu_src
*src
)
234 if (!src
) return blank_alu_src
;
236 midgard_vector_alu_src alu_src
= {
238 .negate
= src
->negate
,
241 .half
= 0, /* TODO */
242 .swizzle
= SWIZZLE_FROM_ARRAY(src
->swizzle
)
248 /* 'Intrinsic' move for misc aliasing uses independent of actual NIR ALU code */
250 static midgard_instruction
251 v_fmov(unsigned src
, midgard_vector_alu_src mod
, unsigned dest
)
253 midgard_instruction ins
= {
256 .src0
= SSA_UNUSED_1
,
261 .op
= midgard_alu_op_fmov
,
262 .reg_mode
= midgard_reg_mode_full
,
263 .dest_override
= midgard_dest_override_none
,
265 .src1
= vector_alu_srco_unsigned(zero_alu_src
),
266 .src2
= vector_alu_srco_unsigned(mod
)
273 /* load/store instructions have both 32-bit and 16-bit variants, depending on
274 * whether we are using vectors composed of highp or mediump. At the moment, we
275 * don't support half-floats -- this requires changes in other parts of the
276 * compiler -- therefore the 16-bit versions are commented out. */
278 //M_LOAD(load_attr_16);
279 M_LOAD(load_attr_32
);
280 //M_LOAD(load_vary_16);
281 M_LOAD(load_vary_32
);
282 //M_LOAD(load_uniform_16);
283 M_LOAD(load_uniform_32
);
284 M_LOAD(load_color_buffer_8
);
285 //M_STORE(store_vary_16);
286 M_STORE(store_vary_32
);
288 static midgard_instruction
289 v_alu_br_compact_cond(midgard_jmp_writeout_op op
, unsigned tag
, signed offset
, unsigned cond
)
291 midgard_branch_cond branch
= {
299 memcpy(&compact
, &branch
, sizeof(branch
));
301 midgard_instruction ins
= {
303 .unit
= ALU_ENAB_BR_COMPACT
,
304 .prepacked_branch
= true,
305 .compact_branch
= true,
306 .br_compact
= compact
309 if (op
== midgard_jmp_writeout_op_writeout
)
315 static midgard_instruction
316 v_branch(bool conditional
, bool invert
)
318 midgard_instruction ins
= {
320 .unit
= ALU_ENAB_BRANCH
,
321 .compact_branch
= true,
323 .conditional
= conditional
,
324 .invert_conditional
= invert
331 static midgard_branch_extended
332 midgard_create_branch_extended( midgard_condition cond
,
333 midgard_jmp_writeout_op op
,
335 signed quadword_offset
)
337 /* For unclear reasons, the condition code is repeated 8 times */
338 uint16_t duplicated_cond
=
348 midgard_branch_extended branch
= {
350 .dest_tag
= dest_tag
,
351 .offset
= quadword_offset
,
352 .cond
= duplicated_cond
358 typedef struct midgard_bundle
{
359 /* Tag for the overall bundle */
362 /* Instructions contained by the bundle */
363 int instruction_count
;
364 midgard_instruction instructions
[5];
366 /* Bundle-wide ALU configuration */
369 bool has_embedded_constants
;
371 bool has_blend_constant
;
373 uint16_t register_words
[8];
374 int register_words_count
;
376 uint64_t body_words
[8];
378 int body_words_count
;
381 typedef struct compiler_context
{
383 gl_shader_stage stage
;
385 /* Is internally a blend shader? Depends on stage == FRAGMENT */
388 /* Tracking for blend constant patching */
389 int blend_constant_number
;
390 int blend_constant_offset
;
392 /* Current NIR function */
395 /* Unordered list of midgard_blocks */
397 struct list_head blocks
;
399 midgard_block
*initial_block
;
400 midgard_block
*previous_source_block
;
401 midgard_block
*final_block
;
403 /* List of midgard_instructions emitted for the current block */
404 midgard_block
*current_block
;
406 /* The index corresponding to the current loop, e.g. for breaks/contineus */
409 /* Constants which have been loaded, for later inlining */
410 struct hash_table_u64
*ssa_constants
;
412 /* SSA indices to be outputted to corresponding varying offset */
413 struct hash_table_u64
*ssa_varyings
;
415 /* SSA values / registers which have been aliased. Naively, these
416 * demand a fmov output; instead, we alias them in a later pass to
417 * avoid the wasted op.
419 * A note on encoding: to avoid dynamic memory management here, rather
420 * than ampping to a pointer, we map to the source index; the key
421 * itself is just the destination index. */
423 struct hash_table_u64
*ssa_to_alias
;
424 struct set
*leftover_ssa_to_alias
;
426 /* Actual SSA-to-register for RA */
427 struct hash_table_u64
*ssa_to_register
;
429 /* Mapping of hashes computed from NIR indices to the sequential temp indices ultimately used in MIR */
430 struct hash_table_u64
*hash_to_temp
;
434 /* Uniform IDs for mdg */
435 struct hash_table_u64
*uniform_nir_to_mdg
;
438 /* Just the count of the max register used. Higher count => higher
439 * register pressure */
442 /* Used for cont/last hinting. Increase when a tex op is added.
443 * Decrease when a tex op is removed. */
444 int texture_op_count
;
446 /* Mapping of texture register -> SSA index for unaliasing */
447 int texture_index
[2];
449 /* Count of special uniforms (viewport, etc) in vec4 units */
450 int special_uniforms
;
452 /* If any path hits a discard instruction */
455 /* The number of uniforms allowable for the fast path */
458 /* Count of instructions emitted from NIR overall, across all blocks */
459 int instruction_count
;
461 /* Alpha ref value passed in */
464 /* The index corresponding to the fragment output */
465 unsigned fragment_output
;
468 /* Append instruction to end of current block */
470 static midgard_instruction
*
471 mir_upload_ins(struct midgard_instruction ins
)
473 midgard_instruction
*heap
= malloc(sizeof(ins
));
474 memcpy(heap
, &ins
, sizeof(ins
));
479 emit_mir_instruction(struct compiler_context
*ctx
, struct midgard_instruction ins
)
481 list_addtail(&(mir_upload_ins(ins
))->link
, &ctx
->current_block
->instructions
);
485 mir_insert_instruction_before(struct midgard_instruction
*tag
, struct midgard_instruction ins
)
487 list_addtail(&(mir_upload_ins(ins
))->link
, &tag
->link
);
491 mir_remove_instruction(struct midgard_instruction
*ins
)
493 list_del(&ins
->link
);
496 static midgard_instruction
*
497 mir_prev_op(struct midgard_instruction
*ins
)
499 return list_last_entry(&(ins
->link
), midgard_instruction
, link
);
502 static midgard_instruction
*
503 mir_next_op(struct midgard_instruction
*ins
)
505 return list_first_entry(&(ins
->link
), midgard_instruction
, link
);
508 static midgard_block
*
509 mir_next_block(struct midgard_block
*blk
)
511 return list_first_entry(&(blk
->link
), midgard_block
, link
);
515 #define mir_foreach_block(ctx, v) list_for_each_entry(struct midgard_block, v, &ctx->blocks, link)
516 #define mir_foreach_block_from(ctx, from, v) list_for_each_entry_from(struct midgard_block, v, from, &ctx->blocks, link)
518 #define mir_foreach_instr(ctx, v) list_for_each_entry(struct midgard_instruction, v, &ctx->current_block->instructions, link)
519 #define mir_foreach_instr_safe(ctx, v) list_for_each_entry_safe(struct midgard_instruction, v, &ctx->current_block->instructions, link)
520 #define mir_foreach_instr_in_block(block, v) list_for_each_entry(struct midgard_instruction, v, &block->instructions, link)
521 #define mir_foreach_instr_in_block_safe(block, v) list_for_each_entry_safe(struct midgard_instruction, v, &block->instructions, link)
522 #define mir_foreach_instr_in_block_safe_rev(block, v) list_for_each_entry_safe_rev(struct midgard_instruction, v, &block->instructions, link)
523 #define mir_foreach_instr_in_block_from(block, v, from) list_for_each_entry_from(struct midgard_instruction, v, from, &block->instructions, link)
526 static midgard_instruction
*
527 mir_last_in_block(struct midgard_block
*block
)
529 return list_last_entry(&block
->instructions
, struct midgard_instruction
, link
);
532 static midgard_block
*
533 mir_get_block(compiler_context
*ctx
, int idx
)
535 struct list_head
*lst
= &ctx
->blocks
;
540 return (struct midgard_block
*) lst
;
543 /* Pretty printer for internal Midgard IR */
546 print_mir_source(int source
)
548 if (source
>= SSA_FIXED_MINIMUM
) {
549 /* Specific register */
550 int reg
= SSA_REG_FROM_FIXED(source
);
552 /* TODO: Moving threshold */
553 if (reg
> 16 && reg
< 24)
554 printf("u%d", 23 - reg
);
558 printf("%d", source
);
563 print_mir_instruction(midgard_instruction
*ins
)
569 midgard_alu_op op
= ins
->alu
.op
;
570 const char *name
= alu_opcode_names
[op
];
573 printf("%d.", ins
->unit
);
575 printf("%s", name
? name
: "??");
579 case TAG_LOAD_STORE_4
: {
580 midgard_load_store_op op
= ins
->load_store
.op
;
581 const char *name
= load_store_opcode_names
[op
];
588 case TAG_TEXTURE_4
: {
597 ssa_args
*args
= &ins
->ssa_args
;
599 printf(" %d, ", args
->dest
);
601 print_mir_source(args
->src0
);
604 if (args
->inline_constant
)
605 printf("#%d", ins
->inline_constant
);
607 print_mir_source(args
->src1
);
609 if (ins
->has_constants
)
610 printf(" <%f, %f, %f, %f>", ins
->constants
[0], ins
->constants
[1], ins
->constants
[2], ins
->constants
[3]);
616 print_mir_block(midgard_block
*block
)
620 mir_foreach_instr_in_block(block
, ins
) {
621 print_mir_instruction(ins
);
630 attach_constants(compiler_context
*ctx
, midgard_instruction
*ins
, void *constants
, int name
)
632 ins
->has_constants
= true;
633 memcpy(&ins
->constants
, constants
, 16);
635 /* If this is the special blend constant, mark this instruction */
637 if (ctx
->is_blend
&& ctx
->blend_constant_number
== name
)
638 ins
->has_blend_constant
= true;
642 glsl_type_size(const struct glsl_type
*type
)
644 return glsl_count_attribute_slots(type
, false);
647 /* Lower fdot2 to a vector multiplication followed by channel addition */
649 midgard_nir_lower_fdot2_body(nir_builder
*b
, nir_alu_instr
*alu
)
651 if (alu
->op
!= nir_op_fdot2
)
654 b
->cursor
= nir_before_instr(&alu
->instr
);
656 nir_ssa_def
*src0
= nir_ssa_for_alu_src(b
, alu
, 0);
657 nir_ssa_def
*src1
= nir_ssa_for_alu_src(b
, alu
, 1);
659 nir_ssa_def
*product
= nir_fmul(b
, src0
, src1
);
661 nir_ssa_def
*sum
= nir_fadd(b
,
662 nir_channel(b
, product
, 0),
663 nir_channel(b
, product
, 1));
665 /* Replace the fdot2 with this sum */
666 nir_ssa_def_rewrite_uses(&alu
->dest
.dest
.ssa
, nir_src_for_ssa(sum
));
670 midgard_nir_lower_fdot2(nir_shader
*shader
)
672 bool progress
= false;
674 nir_foreach_function(function
, shader
) {
675 if (!function
->impl
) continue;
678 nir_builder
*b
= &_b
;
679 nir_builder_init(b
, function
->impl
);
681 nir_foreach_block(block
, function
->impl
) {
682 nir_foreach_instr_safe(instr
, block
) {
683 if (instr
->type
!= nir_instr_type_alu
) continue;
685 nir_alu_instr
*alu
= nir_instr_as_alu(instr
);
686 midgard_nir_lower_fdot2_body(b
, alu
);
692 nir_metadata_preserve(function
->impl
, nir_metadata_block_index
| nir_metadata_dominance
);
700 optimise_nir(nir_shader
*nir
)
704 NIR_PASS(progress
, nir
, nir_lower_regs_to_ssa
);
705 NIR_PASS(progress
, nir
, midgard_nir_lower_fdot2
);
707 nir_lower_tex_options lower_tex_options
= {
711 NIR_PASS(progress
, nir
, nir_lower_tex
, &lower_tex_options
);
716 NIR_PASS(progress
, nir
, midgard_nir_lower_algebraic
);
717 NIR_PASS(progress
, nir
, nir_lower_io
, nir_var_all
, glsl_type_size
, 0);
718 NIR_PASS(progress
, nir
, nir_lower_var_copies
);
719 NIR_PASS(progress
, nir
, nir_lower_vars_to_ssa
);
721 NIR_PASS(progress
, nir
, nir_copy_prop
);
722 NIR_PASS(progress
, nir
, nir_opt_dce
);
723 NIR_PASS(progress
, nir
, nir_opt_dead_cf
);
724 NIR_PASS(progress
, nir
, nir_opt_cse
);
725 NIR_PASS(progress
, nir
, nir_opt_peephole_select
, 64, false, true);
726 NIR_PASS(progress
, nir
, nir_opt_algebraic
);
727 NIR_PASS(progress
, nir
, nir_opt_constant_folding
);
728 NIR_PASS(progress
, nir
, nir_opt_undef
);
729 NIR_PASS(progress
, nir
, nir_opt_loop_unroll
,
732 nir_var_function_temp
);
734 /* TODO: Enable vectorize when merged upstream */
735 // NIR_PASS(progress, nir, nir_opt_vectorize);
738 /* Must be run at the end to prevent creation of fsin/fcos ops */
739 NIR_PASS(progress
, nir
, midgard_nir_scale_trig
);
744 NIR_PASS(progress
, nir
, nir_opt_dce
);
745 NIR_PASS(progress
, nir
, nir_opt_algebraic
);
746 NIR_PASS(progress
, nir
, nir_opt_constant_folding
);
747 NIR_PASS(progress
, nir
, nir_copy_prop
);
750 NIR_PASS(progress
, nir
, nir_opt_algebraic_late
);
751 NIR_PASS(progress
, nir
, midgard_nir_lower_algebraic_late
);
753 /* Lower mods for float ops only. Integer ops don't support modifiers
754 * (saturate doesn't make sense on integers, neg/abs require dedicated
757 NIR_PASS(progress
, nir
, nir_lower_to_source_mods
, nir_lower_float_source_mods
);
758 NIR_PASS(progress
, nir
, nir_copy_prop
);
759 NIR_PASS(progress
, nir
, nir_opt_dce
);
761 /* We implement booleans as 32-bit 0/~0 */
762 NIR_PASS(progress
, nir
, nir_lower_bool_to_int32
);
764 /* Take us out of SSA */
765 NIR_PASS(progress
, nir
, nir_lower_locals_to_regs
);
766 NIR_PASS(progress
, nir
, nir_convert_from_ssa
, true);
768 /* We are a vector architecture; write combine where possible */
769 NIR_PASS(progress
, nir
, nir_move_vec_src_uses_to_dest
);
770 NIR_PASS(progress
, nir
, nir_lower_vec_to_movs
);
772 NIR_PASS(progress
, nir
, nir_opt_dce
);
775 /* Front-half of aliasing the SSA slots, merely by inserting the flag in the
776 * appropriate hash table. Intentional off-by-one to avoid confusing NULL with
777 * r0. See the comments in compiler_context */
780 alias_ssa(compiler_context
*ctx
, int dest
, int src
)
782 _mesa_hash_table_u64_insert(ctx
->ssa_to_alias
, dest
+ 1, (void *) ((uintptr_t) src
+ 1));
783 _mesa_set_add(ctx
->leftover_ssa_to_alias
, (void *) (uintptr_t) (dest
+ 1));
786 /* ...or undo it, after which the original index will be used (dummy move should be emitted alongside this) */
789 unalias_ssa(compiler_context
*ctx
, int dest
)
791 _mesa_hash_table_u64_remove(ctx
->ssa_to_alias
, dest
+ 1);
792 /* TODO: Remove from leftover or no? */
796 midgard_pin_output(compiler_context
*ctx
, int index
, int reg
)
798 _mesa_hash_table_u64_insert(ctx
->ssa_to_register
, index
+ 1, (void *) ((uintptr_t) reg
+ 1));
802 midgard_is_pinned(compiler_context
*ctx
, int index
)
804 return _mesa_hash_table_u64_search(ctx
->ssa_to_register
, index
+ 1) != NULL
;
807 /* Do not actually emit a load; instead, cache the constant for inlining */
810 emit_load_const(compiler_context
*ctx
, nir_load_const_instr
*instr
)
812 nir_ssa_def def
= instr
->def
;
814 float *v
= ralloc_array(NULL
, float, 4);
815 memcpy(v
, &instr
->value
.f32
, 4 * sizeof(float));
816 _mesa_hash_table_u64_insert(ctx
->ssa_constants
, def
.index
+ 1, v
);
819 /* Duplicate bits to convert sane 4-bit writemask to obscure 8-bit format (or
823 expand_writemask(unsigned mask
)
827 for (int i
= 0; i
< 4; ++i
)
835 squeeze_writemask(unsigned mask
)
839 for (int i
= 0; i
< 4; ++i
)
840 if (mask
& (3 << (2 * i
)))
847 /* Determines effective writemask, taking quirks and expansion into account */
849 effective_writemask(midgard_vector_alu
*alu
)
851 /* Channel count is off-by-one to fit in two-bits (0 channel makes no
854 unsigned channel_count
= GET_CHANNEL_COUNT(alu_opcode_props
[alu
->op
]);
856 /* If there is a fixed channel count, construct the appropriate mask */
859 return (1 << channel_count
) - 1;
861 /* Otherwise, just squeeze the existing mask */
862 return squeeze_writemask(alu
->mask
);
866 find_or_allocate_temp(compiler_context
*ctx
, unsigned hash
)
868 if ((hash
< 0) || (hash
>= SSA_FIXED_MINIMUM
))
871 unsigned temp
= (uintptr_t) _mesa_hash_table_u64_search(ctx
->hash_to_temp
, hash
+ 1);
876 /* If no temp is find, allocate one */
877 temp
= ctx
->temp_count
++;
878 ctx
->max_hash
= MAX2(ctx
->max_hash
, hash
);
880 _mesa_hash_table_u64_insert(ctx
->hash_to_temp
, hash
+ 1, (void *) ((uintptr_t) temp
+ 1));
886 nir_src_index(compiler_context
*ctx
, nir_src
*src
)
889 return src
->ssa
->index
;
891 return ctx
->func
->impl
->ssa_alloc
+ src
->reg
.reg
->index
;
895 nir_dest_index(compiler_context
*ctx
, nir_dest
*dst
)
898 return dst
->ssa
.index
;
900 return ctx
->func
->impl
->ssa_alloc
+ dst
->reg
.reg
->index
;
904 nir_alu_src_index(compiler_context
*ctx
, nir_alu_src
*src
)
906 return nir_src_index(ctx
, &src
->src
);
909 /* Midgard puts conditionals in r31.w; move an arbitrary source (the output of
910 * a conditional test) into that register */
913 emit_condition(compiler_context
*ctx
, nir_src
*src
, bool for_branch
)
915 /* XXX: Force component correct */
916 int condition
= nir_src_index(ctx
, src
);
918 /* There is no boolean move instruction. Instead, we simulate a move by
919 * ANDing the condition with itself to get it into r31.w */
921 midgard_instruction ins
= {
923 .unit
= for_branch
? UNIT_SMUL
: UNIT_SADD
, /* TODO: DEDUCE THIS */
927 .dest
= SSA_FIXED_REGISTER(31),
930 .op
= midgard_alu_op_iand
,
931 .reg_mode
= midgard_reg_mode_full
,
932 .dest_override
= midgard_dest_override_none
,
933 .mask
= (0x3 << 6), /* w */
934 .src1
= vector_alu_srco_unsigned(blank_alu_src_xxxx
),
935 .src2
= vector_alu_srco_unsigned(blank_alu_src_xxxx
)
939 emit_mir_instruction(ctx
, ins
);
942 #define ALU_CASE(nir, _op) \
944 op = midgard_alu_op_##_op; \
948 emit_alu(compiler_context
*ctx
, nir_alu_instr
*instr
)
950 bool is_ssa
= instr
->dest
.dest
.is_ssa
;
952 unsigned dest
= nir_dest_index(ctx
, &instr
->dest
.dest
);
953 unsigned nr_components
= is_ssa
? instr
->dest
.dest
.ssa
.num_components
: instr
->dest
.dest
.reg
.reg
->num_components
;
954 unsigned nr_inputs
= nir_op_infos
[instr
->op
].num_inputs
;
956 /* Most Midgard ALU ops have a 1:1 correspondance to NIR ops; these are
957 * supported. A few do not and are commented for now. Also, there are a
958 * number of NIR ops which Midgard does not support and need to be
959 * lowered, also TODO. This switch block emits the opcode and calling
960 * convention of the Midgard instruction; actual packing is done in
966 ALU_CASE(fadd
, fadd
);
967 ALU_CASE(fmul
, fmul
);
968 ALU_CASE(fmin
, fmin
);
969 ALU_CASE(fmax
, fmax
);
970 ALU_CASE(imin
, imin
);
971 ALU_CASE(imax
, imax
);
972 ALU_CASE(fmov
, fmov
);
973 ALU_CASE(ffloor
, ffloor
);
974 ALU_CASE(fround_even
, froundeven
);
975 ALU_CASE(ftrunc
, ftrunc
);
976 ALU_CASE(fceil
, fceil
);
977 ALU_CASE(fdot3
, fdot3
);
978 ALU_CASE(fdot4
, fdot4
);
979 ALU_CASE(iadd
, iadd
);
980 ALU_CASE(isub
, isub
);
981 ALU_CASE(imul
, imul
);
982 ALU_CASE(iabs
, iabs
);
984 /* XXX: Use fmov, not imov, since imov was causing major
985 * issues with texture precision? XXX research */
986 ALU_CASE(imov
, fmov
);
988 ALU_CASE(feq32
, feq
);
989 ALU_CASE(fne32
, fne
);
990 ALU_CASE(flt32
, flt
);
991 ALU_CASE(ieq32
, ieq
);
992 ALU_CASE(ine32
, ine
);
993 ALU_CASE(ilt32
, ilt
);
994 ALU_CASE(ult32
, ult
);
996 /* We don't have a native b2f32 instruction. Instead, like many
997 * GPUs, we exploit booleans as 0/~0 for false/true, and
998 * correspondingly AND
999 * by 1.0 to do the type conversion. For the moment, prime us
1002 * iand [whatever], #0
1004 * At the end of emit_alu (as MIR), we'll fix-up the constant
1007 ALU_CASE(b2f32
, iand
);
1008 ALU_CASE(b2i32
, iand
);
1010 /* Likewise, we don't have a dedicated f2b32 instruction, but
1011 * we can do a "not equal to 0.0" test. */
1013 ALU_CASE(f2b32
, fne
);
1014 ALU_CASE(i2b32
, ine
);
1016 ALU_CASE(frcp
, frcp
);
1017 ALU_CASE(frsq
, frsqrt
);
1018 ALU_CASE(fsqrt
, fsqrt
);
1019 ALU_CASE(fpow
, fpow
);
1020 ALU_CASE(fexp2
, fexp2
);
1021 ALU_CASE(flog2
, flog2
);
1023 ALU_CASE(f2i32
, f2i
);
1024 ALU_CASE(f2u32
, f2u
);
1025 ALU_CASE(i2f32
, i2f
);
1026 ALU_CASE(u2f32
, u2f
);
1028 ALU_CASE(fsin
, fsin
);
1029 ALU_CASE(fcos
, fcos
);
1031 ALU_CASE(iand
, iand
);
1033 ALU_CASE(ixor
, ixor
);
1034 ALU_CASE(inot
, inot
);
1035 ALU_CASE(ishl
, ishl
);
1036 ALU_CASE(ishr
, iasr
);
1037 ALU_CASE(ushr
, ilsr
);
1039 ALU_CASE(b32all_fequal2
, fball_eq
);
1040 ALU_CASE(b32all_fequal3
, fball_eq
);
1041 ALU_CASE(b32all_fequal4
, fball_eq
);
1043 ALU_CASE(b32any_fnequal2
, fbany_neq
);
1044 ALU_CASE(b32any_fnequal3
, fbany_neq
);
1045 ALU_CASE(b32any_fnequal4
, fbany_neq
);
1047 ALU_CASE(b32all_iequal2
, iball_eq
);
1048 ALU_CASE(b32all_iequal3
, iball_eq
);
1049 ALU_CASE(b32all_iequal4
, iball_eq
);
1051 ALU_CASE(b32any_inequal2
, ibany_neq
);
1052 ALU_CASE(b32any_inequal3
, ibany_neq
);
1053 ALU_CASE(b32any_inequal4
, ibany_neq
);
1055 /* For greater-or-equal, we use less-or-equal and flip the
1058 case nir_op_ige32
: {
1059 op
= midgard_alu_op_ile
;
1061 /* Swap via temporary */
1062 nir_alu_src temp
= instr
->src
[1];
1063 instr
->src
[1] = instr
->src
[0];
1064 instr
->src
[0] = temp
;
1069 case nir_op_b32csel
: {
1070 op
= midgard_alu_op_fcsel
;
1072 /* csel works as a two-arg in Midgard, since the condition is hardcoded in r31.w */
1075 emit_condition(ctx
, &instr
->src
[0].src
, false);
1077 /* The condition is the first argument; move the other
1078 * arguments up one to be a binary instruction for
1081 memmove(instr
->src
, instr
->src
+ 1, 2 * sizeof(nir_alu_src
));
1086 DBG("Unhandled ALU op %s\n", nir_op_infos
[instr
->op
].name
);
1091 /* Fetch unit, quirks, etc information */
1092 unsigned opcode_props
= alu_opcode_props
[op
];
1093 bool quirk_flipped_r24
= opcode_props
& QUIRK_FLIPPED_R24
;
1095 /* Initialise fields common between scalar/vector instructions */
1096 midgard_outmod outmod
= instr
->dest
.saturate
? midgard_outmod_sat
: midgard_outmod_none
;
1098 /* src0 will always exist afaik, but src1 will not for 1-argument
1099 * instructions. The latter can only be fetched if the instruction
1100 * needs it, or else we may segfault. */
1102 unsigned src0
= nir_alu_src_index(ctx
, &instr
->src
[0]);
1103 unsigned src1
= nr_inputs
== 2 ? nir_alu_src_index(ctx
, &instr
->src
[1]) : SSA_UNUSED_0
;
1105 /* Rather than use the instruction generation helpers, we do it
1106 * ourselves here to avoid the mess */
1108 midgard_instruction ins
= {
1111 .src0
= quirk_flipped_r24
? SSA_UNUSED_1
: src0
,
1112 .src1
= quirk_flipped_r24
? src0
: src1
,
1117 nir_alu_src
*nirmods
[2] = { NULL
};
1119 if (nr_inputs
== 2) {
1120 nirmods
[0] = &instr
->src
[0];
1121 nirmods
[1] = &instr
->src
[1];
1122 } else if (nr_inputs
== 1) {
1123 nirmods
[quirk_flipped_r24
] = &instr
->src
[0];
1128 midgard_vector_alu alu
= {
1130 .reg_mode
= midgard_reg_mode_full
,
1131 .dest_override
= midgard_dest_override_none
,
1134 /* Writemask only valid for non-SSA NIR */
1135 .mask
= expand_writemask((1 << nr_components
) - 1),
1137 .src1
= vector_alu_srco_unsigned(vector_alu_modifiers(nirmods
[0])),
1138 .src2
= vector_alu_srco_unsigned(vector_alu_modifiers(nirmods
[1])),
1141 /* Apply writemask if non-SSA, keeping in mind that we can't write to components that don't exist */
1144 alu
.mask
&= expand_writemask(instr
->dest
.write_mask
);
1148 /* Late fixup for emulated instructions */
1150 if (instr
->op
== nir_op_b2f32
|| instr
->op
== nir_op_b2i32
) {
1151 /* Presently, our second argument is an inline #0 constant.
1152 * Switch over to an embedded 1.0 constant (that can't fit
1153 * inline, since we're 32-bit, not 16-bit like the inline
1156 ins
.ssa_args
.inline_constant
= false;
1157 ins
.ssa_args
.src1
= SSA_FIXED_REGISTER(REGISTER_CONSTANT
);
1158 ins
.has_constants
= true;
1160 if (instr
->op
== nir_op_b2f32
) {
1161 ins
.constants
[0] = 1.0f
;
1163 /* Type pun it into place */
1165 memcpy(&ins
.constants
[0], &one
, sizeof(uint32_t));
1168 ins
.alu
.src2
= vector_alu_srco_unsigned(blank_alu_src_xxxx
);
1169 } else if (instr
->op
== nir_op_f2b32
) {
1170 ins
.ssa_args
.inline_constant
= false;
1171 ins
.ssa_args
.src1
= SSA_FIXED_REGISTER(REGISTER_CONSTANT
);
1172 ins
.has_constants
= true;
1173 ins
.constants
[0] = 0.0f
;
1174 ins
.alu
.src2
= vector_alu_srco_unsigned(blank_alu_src_xxxx
);
1177 if ((opcode_props
& UNITS_ALL
) == UNIT_VLUT
) {
1178 /* To avoid duplicating the lookup tables (probably), true LUT
1179 * instructions can only operate as if they were scalars. Lower
1180 * them here by changing the component. */
1182 uint8_t original_swizzle
[4];
1183 memcpy(original_swizzle
, nirmods
[0]->swizzle
, sizeof(nirmods
[0]->swizzle
));
1185 for (int i
= 0; i
< nr_components
; ++i
) {
1186 ins
.alu
.mask
= (0x3) << (2 * i
); /* Mask the associated component */
1188 for (int j
= 0; j
< 4; ++j
)
1189 nirmods
[0]->swizzle
[j
] = original_swizzle
[i
]; /* Pull from the correct component */
1191 ins
.alu
.src1
= vector_alu_srco_unsigned(vector_alu_modifiers(nirmods
[0]));
1192 emit_mir_instruction(ctx
, ins
);
1195 emit_mir_instruction(ctx
, ins
);
1202 emit_intrinsic(compiler_context
*ctx
, nir_intrinsic_instr
*instr
)
1204 nir_const_value
*const_offset
;
1205 unsigned offset
, reg
;
1207 switch (instr
->intrinsic
) {
1208 case nir_intrinsic_discard_if
:
1209 emit_condition(ctx
, &instr
->src
[0], true);
1213 case nir_intrinsic_discard
: {
1214 bool conditional
= instr
->intrinsic
== nir_intrinsic_discard_if
;
1215 struct midgard_instruction discard
= v_branch(conditional
, false);
1216 discard
.branch
.target_type
= TARGET_DISCARD
;
1217 emit_mir_instruction(ctx
, discard
);
1219 ctx
->can_discard
= true;
1223 case nir_intrinsic_load_uniform
:
1224 case nir_intrinsic_load_input
:
1225 const_offset
= nir_src_as_const_value(instr
->src
[0]);
1226 assert (const_offset
&& "no indirect inputs");
1228 offset
= nir_intrinsic_base(instr
) + const_offset
->u32
[0];
1230 reg
= nir_dest_index(ctx
, &instr
->dest
);
1232 if (instr
->intrinsic
== nir_intrinsic_load_uniform
&& !ctx
->is_blend
) {
1233 /* TODO: half-floats */
1235 int uniform_offset
= 0;
1237 if (offset
>= SPECIAL_UNIFORM_BASE
) {
1238 /* XXX: Resolve which uniform */
1241 /* Offset away from the special
1244 void *entry
= _mesa_hash_table_u64_search(ctx
->uniform_nir_to_mdg
, offset
+ 1);
1248 DBG("WARNING: Unknown uniform %d\n", offset
);
1252 uniform_offset
= (uintptr_t) (entry
) - 1;
1253 uniform_offset
+= ctx
->special_uniforms
;
1256 if (uniform_offset
< ctx
->uniform_cutoff
) {
1257 /* Fast path: For the first 16 uniform,
1258 * accesses are 0-cycle, since they're
1259 * just a register fetch in the usual
1260 * case. So, we alias the registers
1261 * while we're still in SSA-space */
1263 int reg_slot
= 23 - uniform_offset
;
1264 alias_ssa(ctx
, reg
, SSA_FIXED_REGISTER(reg_slot
));
1266 /* Otherwise, read from the 'special'
1267 * UBO to access higher-indexed
1268 * uniforms, at a performance cost */
1270 midgard_instruction ins
= m_load_uniform_32(reg
, uniform_offset
);
1272 /* TODO: Don't split */
1273 ins
.load_store
.varying_parameters
= (uniform_offset
& 7) << 7;
1274 ins
.load_store
.address
= uniform_offset
>> 3;
1276 ins
.load_store
.unknown
= 0x1E00; /* xxx: what is this? */
1277 emit_mir_instruction(ctx
, ins
);
1279 } else if (ctx
->stage
== MESA_SHADER_FRAGMENT
&& !ctx
->is_blend
) {
1280 /* XXX: Half-floats? */
1281 /* TODO: swizzle, mask */
1283 midgard_instruction ins
= m_load_vary_32(reg
, offset
);
1285 midgard_varying_parameter p
= {
1287 .interpolation
= midgard_interp_default
,
1288 .flat
= /*var->data.interpolation == INTERP_MODE_FLAT*/ 0
1292 memcpy(&u
, &p
, sizeof(p
));
1293 ins
.load_store
.varying_parameters
= u
;
1295 ins
.load_store
.unknown
= 0x1e9e; /* xxx: what is this? */
1296 emit_mir_instruction(ctx
, ins
);
1297 } else if (ctx
->is_blend
&& instr
->intrinsic
== nir_intrinsic_load_uniform
) {
1298 /* Constant encoded as a pinned constant */
1300 midgard_instruction ins
= v_fmov(SSA_FIXED_REGISTER(REGISTER_CONSTANT
), blank_alu_src
, reg
);
1301 ins
.has_constants
= true;
1302 ins
.has_blend_constant
= true;
1303 emit_mir_instruction(ctx
, ins
);
1304 } else if (ctx
->is_blend
) {
1305 /* For blend shaders, a load might be
1306 * translated various ways depending on what
1307 * we're loading. Figure out how this is used */
1309 nir_variable
*out
= NULL
;
1311 nir_foreach_variable(var
, &ctx
->nir
->inputs
) {
1312 int drvloc
= var
->data
.driver_location
;
1314 if (nir_intrinsic_base(instr
) == drvloc
) {
1322 if (out
->data
.location
== VARYING_SLOT_COL0
) {
1323 /* Source color preloaded to r0 */
1325 midgard_pin_output(ctx
, reg
, 0);
1326 } else if (out
->data
.location
== VARYING_SLOT_COL1
) {
1327 /* Destination color must be read from framebuffer */
1329 midgard_instruction ins
= m_load_color_buffer_8(reg
, 0);
1330 ins
.load_store
.swizzle
= 0; /* xxxx */
1332 /* Read each component sequentially */
1334 for (int c
= 0; c
< 4; ++c
) {
1335 ins
.load_store
.mask
= (1 << c
);
1336 ins
.load_store
.unknown
= c
;
1337 emit_mir_instruction(ctx
, ins
);
1340 /* vadd.u2f hr2, abs(hr2), #0 */
1342 midgard_vector_alu_src alu_src
= blank_alu_src
;
1344 alu_src
.half
= true;
1346 midgard_instruction u2f
= {
1350 .src1
= SSA_UNUSED_0
,
1352 .inline_constant
= true
1355 .op
= midgard_alu_op_u2f
,
1356 .reg_mode
= midgard_reg_mode_half
,
1357 .dest_override
= midgard_dest_override_none
,
1359 .src1
= vector_alu_srco_unsigned(alu_src
),
1360 .src2
= vector_alu_srco_unsigned(blank_alu_src
),
1364 emit_mir_instruction(ctx
, u2f
);
1366 /* vmul.fmul.sat r1, hr2, #0.00392151 */
1368 alu_src
.abs
= false;
1370 midgard_instruction fmul
= {
1372 .inline_constant
= _mesa_float_to_half(1.0 / 255.0),
1376 .src1
= SSA_UNUSED_0
,
1377 .inline_constant
= true
1380 .op
= midgard_alu_op_fmul
,
1381 .reg_mode
= midgard_reg_mode_full
,
1382 .dest_override
= midgard_dest_override_none
,
1383 .outmod
= midgard_outmod_sat
,
1385 .src1
= vector_alu_srco_unsigned(alu_src
),
1386 .src2
= vector_alu_srco_unsigned(blank_alu_src
),
1390 emit_mir_instruction(ctx
, fmul
);
1392 DBG("Unknown input in blend shader\n");
1395 } else if (ctx
->stage
== MESA_SHADER_VERTEX
) {
1396 midgard_instruction ins
= m_load_attr_32(reg
, offset
);
1397 ins
.load_store
.unknown
= 0x1E1E; /* XXX: What is this? */
1398 ins
.load_store
.mask
= (1 << instr
->num_components
) - 1;
1399 emit_mir_instruction(ctx
, ins
);
1401 DBG("Unknown load\n");
1407 case nir_intrinsic_store_output
:
1408 const_offset
= nir_src_as_const_value(instr
->src
[1]);
1409 assert(const_offset
&& "no indirect outputs");
1411 offset
= nir_intrinsic_base(instr
) + const_offset
->u32
[0];
1413 reg
= nir_src_index(ctx
, &instr
->src
[0]);
1415 if (ctx
->stage
== MESA_SHADER_FRAGMENT
) {
1416 /* gl_FragColor is not emitted with load/store
1417 * instructions. Instead, it gets plonked into
1418 * r0 at the end of the shader and we do the
1419 * framebuffer writeout dance. TODO: Defer
1422 midgard_pin_output(ctx
, reg
, 0);
1424 /* Save the index we're writing to for later reference
1425 * in the epilogue */
1427 ctx
->fragment_output
= reg
;
1428 } else if (ctx
->stage
== MESA_SHADER_VERTEX
) {
1429 /* Varyings are written into one of two special
1430 * varying register, r26 or r27. The register itself is selected as the register
1431 * in the st_vary instruction, minus the base of 26. E.g. write into r27 and then call st_vary(1)
1433 * Normally emitting fmov's is frowned upon,
1434 * but due to unique constraints of
1435 * REGISTER_VARYING, fmov emission + a
1436 * dedicated cleanup pass is the only way to
1437 * guarantee correctness when considering some
1438 * (common) edge cases XXX: FIXME */
1440 /* If this varying corresponds to a constant (why?!),
1441 * emit that now since it won't get picked up by
1442 * hoisting (since there is no corresponding move
1443 * emitted otherwise) */
1445 void *constant_value
= _mesa_hash_table_u64_search(ctx
->ssa_constants
, reg
+ 1);
1447 if (constant_value
) {
1448 /* Special case: emit the varying write
1449 * directly to r26 (looks funny in asm but it's
1450 * fine) and emit the store _now_. Possibly
1451 * slightly slower, but this is a really stupid
1452 * special case anyway (why on earth would you
1453 * have a constant varying? Your own fault for
1454 * slightly worse perf :P) */
1456 midgard_instruction ins
= v_fmov(SSA_FIXED_REGISTER(REGISTER_CONSTANT
), blank_alu_src
, SSA_FIXED_REGISTER(26));
1457 attach_constants(ctx
, &ins
, constant_value
, reg
+ 1);
1458 emit_mir_instruction(ctx
, ins
);
1460 midgard_instruction st
= m_store_vary_32(SSA_FIXED_REGISTER(0), offset
);
1461 st
.load_store
.unknown
= 0x1E9E; /* XXX: What is this? */
1462 emit_mir_instruction(ctx
, st
);
1464 /* Do not emit the varying yet -- instead, just mark down that we need to later */
1466 _mesa_hash_table_u64_insert(ctx
->ssa_varyings
, reg
+ 1, (void *) ((uintptr_t) (offset
+ 1)));
1469 DBG("Unknown store\n");
1475 case nir_intrinsic_load_alpha_ref_float
:
1476 assert(instr
->dest
.is_ssa
);
1478 float ref_value
= ctx
->alpha_ref
;
1480 float *v
= ralloc_array(NULL
, float, 4);
1481 memcpy(v
, &ref_value
, sizeof(float));
1482 _mesa_hash_table_u64_insert(ctx
->ssa_constants
, instr
->dest
.ssa
.index
+ 1, v
);
1487 printf ("Unhandled intrinsic\n");
1494 midgard_tex_format(enum glsl_sampler_dim dim
)
1497 case GLSL_SAMPLER_DIM_2D
:
1498 case GLSL_SAMPLER_DIM_EXTERNAL
:
1501 case GLSL_SAMPLER_DIM_3D
:
1504 case GLSL_SAMPLER_DIM_CUBE
:
1505 return TEXTURE_CUBE
;
1508 DBG("Unknown sampler dim type\n");
1515 emit_tex(compiler_context
*ctx
, nir_tex_instr
*instr
)
1518 //assert (!instr->sampler);
1519 //assert (!instr->texture_array_size);
1520 assert (instr
->op
== nir_texop_tex
);
1522 /* Allocate registers via a round robin scheme to alternate between the two registers */
1523 int reg
= ctx
->texture_op_count
& 1;
1524 int in_reg
= reg
, out_reg
= reg
;
1526 /* Make room for the reg */
1528 if (ctx
->texture_index
[reg
] > -1)
1529 unalias_ssa(ctx
, ctx
->texture_index
[reg
]);
1531 int texture_index
= instr
->texture_index
;
1532 int sampler_index
= texture_index
;
1534 for (unsigned i
= 0; i
< instr
->num_srcs
; ++i
) {
1535 switch (instr
->src
[i
].src_type
) {
1536 case nir_tex_src_coord
: {
1537 int index
= nir_src_index(ctx
, &instr
->src
[i
].src
);
1539 midgard_vector_alu_src alu_src
= blank_alu_src
;
1540 alu_src
.swizzle
= (COMPONENT_Y
<< 2);
1542 midgard_instruction ins
= v_fmov(index
, alu_src
, SSA_FIXED_REGISTER(REGISTER_TEXTURE_BASE
+ in_reg
));
1543 emit_mir_instruction(ctx
, ins
);
1545 //midgard_pin_output(ctx, index, REGISTER_TEXTURE_BASE + in_reg);
1551 DBG("Unknown source type\n");
1558 /* No helper to build texture words -- we do it all here */
1559 midgard_instruction ins
= {
1560 .type
= TAG_TEXTURE_4
,
1562 .op
= TEXTURE_OP_NORMAL
,
1563 .format
= midgard_tex_format(instr
->sampler_dim
),
1564 .texture_handle
= texture_index
,
1565 .sampler_handle
= sampler_index
,
1567 /* TODO: Don't force xyzw */
1568 .swizzle
= SWIZZLE(COMPONENT_X
, COMPONENT_Y
, COMPONENT_Z
, COMPONENT_W
),
1580 /* Assume we can continue; hint it out later */
1585 /* Set registers to read and write from the same place */
1586 ins
.texture
.in_reg_select
= in_reg
;
1587 ins
.texture
.out_reg_select
= out_reg
;
1589 /* TODO: Dynamic swizzle input selection, half-swizzles? */
1590 if (instr
->sampler_dim
== GLSL_SAMPLER_DIM_3D
) {
1591 ins
.texture
.in_reg_swizzle_right
= COMPONENT_X
;
1592 ins
.texture
.in_reg_swizzle_left
= COMPONENT_Y
;
1593 //ins.texture.in_reg_swizzle_third = COMPONENT_Z;
1595 ins
.texture
.in_reg_swizzle_left
= COMPONENT_X
;
1596 ins
.texture
.in_reg_swizzle_right
= COMPONENT_Y
;
1597 //ins.texture.in_reg_swizzle_third = COMPONENT_X;
1600 emit_mir_instruction(ctx
, ins
);
1602 /* Simultaneously alias the destination and emit a move for it. The move will be eliminated if possible */
1604 int o_reg
= REGISTER_TEXTURE_BASE
+ out_reg
, o_index
= nir_dest_index(ctx
, &instr
->dest
);
1605 alias_ssa(ctx
, o_index
, SSA_FIXED_REGISTER(o_reg
));
1606 ctx
->texture_index
[reg
] = o_index
;
1608 midgard_instruction ins2
= v_fmov(SSA_FIXED_REGISTER(o_reg
), blank_alu_src
, o_index
);
1609 emit_mir_instruction(ctx
, ins2
);
1611 /* Used for .cont and .last hinting */
1612 ctx
->texture_op_count
++;
1616 emit_jump(compiler_context
*ctx
, nir_jump_instr
*instr
)
1618 switch (instr
->type
) {
1619 case nir_jump_break
: {
1620 /* Emit a branch out of the loop */
1621 struct midgard_instruction br
= v_branch(false, false);
1622 br
.branch
.target_type
= TARGET_BREAK
;
1623 br
.branch
.target_break
= ctx
->current_loop
;
1624 emit_mir_instruction(ctx
, br
);
1631 DBG("Unknown jump type %d\n", instr
->type
);
1637 emit_instr(compiler_context
*ctx
, struct nir_instr
*instr
)
1639 switch (instr
->type
) {
1640 case nir_instr_type_load_const
:
1641 emit_load_const(ctx
, nir_instr_as_load_const(instr
));
1644 case nir_instr_type_intrinsic
:
1645 emit_intrinsic(ctx
, nir_instr_as_intrinsic(instr
));
1648 case nir_instr_type_alu
:
1649 emit_alu(ctx
, nir_instr_as_alu(instr
));
1652 case nir_instr_type_tex
:
1653 emit_tex(ctx
, nir_instr_as_tex(instr
));
1656 case nir_instr_type_jump
:
1657 emit_jump(ctx
, nir_instr_as_jump(instr
));
1660 case nir_instr_type_ssa_undef
:
1665 DBG("Unhandled instruction type\n");
1670 /* Determine the actual hardware from the index based on the RA results or special values */
1673 dealias_register(compiler_context
*ctx
, struct ra_graph
*g
, int reg
, int maxreg
)
1675 if (reg
>= SSA_FIXED_MINIMUM
)
1676 return SSA_REG_FROM_FIXED(reg
);
1679 assert(reg
< maxreg
);
1680 int r
= ra_get_node_reg(g
, reg
);
1681 ctx
->work_registers
= MAX2(ctx
->work_registers
, r
);
1686 /* fmov style unused */
1688 return REGISTER_UNUSED
;
1690 /* lut style unused */
1692 return REGISTER_UNUSED
;
1695 DBG("Unknown SSA register alias %d\n", reg
);
1702 midgard_ra_select_callback(struct ra_graph
*g
, BITSET_WORD
*regs
, void *data
)
1704 /* Choose the first available register to minimise reported register pressure */
1706 for (int i
= 0; i
< 16; ++i
) {
1707 if (BITSET_TEST(regs
, i
)) {
1717 midgard_is_live_in_instr(midgard_instruction
*ins
, int src
)
1719 if (ins
->ssa_args
.src0
== src
) return true;
1720 if (ins
->ssa_args
.src1
== src
) return true;
1726 is_live_after(compiler_context
*ctx
, midgard_block
*block
, midgard_instruction
*start
, int src
)
1728 /* Check the rest of the block for liveness */
1729 mir_foreach_instr_in_block_from(block
, ins
, mir_next_op(start
)) {
1730 if (midgard_is_live_in_instr(ins
, src
))
1734 /* Check the rest of the blocks for liveness */
1735 mir_foreach_block_from(ctx
, mir_next_block(block
), b
) {
1736 mir_foreach_instr_in_block(b
, ins
) {
1737 if (midgard_is_live_in_instr(ins
, src
))
1742 /* TODO: How does control flow interact in complex shaders? */
1748 allocate_registers(compiler_context
*ctx
)
1750 /* First, initialize the RA */
1751 struct ra_regs
*regs
= ra_alloc_reg_set(NULL
, 32, true);
1753 /* Create a primary (general purpose) class, as well as special purpose
1754 * pipeline register classes */
1756 int primary_class
= ra_alloc_reg_class(regs
);
1757 int varying_class
= ra_alloc_reg_class(regs
);
1759 /* Add the full set of work registers */
1760 int work_count
= 16 - MAX2((ctx
->uniform_cutoff
- 8), 0);
1761 for (int i
= 0; i
< work_count
; ++i
)
1762 ra_class_add_reg(regs
, primary_class
, i
);
1764 /* Add special registers */
1765 ra_class_add_reg(regs
, varying_class
, REGISTER_VARYING_BASE
);
1766 ra_class_add_reg(regs
, varying_class
, REGISTER_VARYING_BASE
+ 1);
1768 /* We're done setting up */
1769 ra_set_finalize(regs
, NULL
);
1771 /* Transform the MIR into squeezed index form */
1772 mir_foreach_block(ctx
, block
) {
1773 mir_foreach_instr_in_block(block
, ins
) {
1774 if (ins
->compact_branch
) continue;
1776 ins
->ssa_args
.src0
= find_or_allocate_temp(ctx
, ins
->ssa_args
.src0
);
1777 ins
->ssa_args
.src1
= find_or_allocate_temp(ctx
, ins
->ssa_args
.src1
);
1778 ins
->ssa_args
.dest
= find_or_allocate_temp(ctx
, ins
->ssa_args
.dest
);
1780 if (midgard_debug
& MIDGARD_DBG_SHADERS
)
1781 print_mir_block(block
);
1784 /* Let's actually do register allocation */
1785 int nodes
= ctx
->temp_count
;
1786 struct ra_graph
*g
= ra_alloc_interference_graph(regs
, nodes
);
1788 /* Set everything to the work register class, unless it has somewhere
1791 mir_foreach_block(ctx
, block
) {
1792 mir_foreach_instr_in_block(block
, ins
) {
1793 if (ins
->compact_branch
) continue;
1795 if (ins
->ssa_args
.dest
< 0) continue;
1797 if (ins
->ssa_args
.dest
>= SSA_FIXED_MINIMUM
) continue;
1799 int class = primary_class
;
1801 ra_set_node_class(g
, ins
->ssa_args
.dest
, class);
1805 for (int index
= 0; index
<= ctx
->max_hash
; ++index
) {
1806 unsigned temp
= (uintptr_t) _mesa_hash_table_u64_search(ctx
->ssa_to_register
, index
+ 1);
1809 unsigned reg
= temp
- 1;
1810 int t
= find_or_allocate_temp(ctx
, index
);
1811 ra_set_node_reg(g
, t
, reg
);
1815 /* Determine liveness */
1817 int *live_start
= malloc(nodes
* sizeof(int));
1818 int *live_end
= malloc(nodes
* sizeof(int));
1820 /* Initialize as non-existent */
1822 for (int i
= 0; i
< nodes
; ++i
) {
1823 live_start
[i
] = live_end
[i
] = -1;
1828 mir_foreach_block(ctx
, block
) {
1829 mir_foreach_instr_in_block(block
, ins
) {
1830 if (ins
->compact_branch
) continue;
1832 if (ins
->ssa_args
.dest
< SSA_FIXED_MINIMUM
) {
1833 /* If this destination is not yet live, it is now since we just wrote it */
1835 int dest
= ins
->ssa_args
.dest
;
1837 if (live_start
[dest
] == -1)
1838 live_start
[dest
] = d
;
1841 /* Since we just used a source, the source might be
1842 * dead now. Scan the rest of the block for
1843 * invocations, and if there are none, the source dies
1846 int sources
[2] = { ins
->ssa_args
.src0
, ins
->ssa_args
.src1
};
1848 for (int src
= 0; src
< 2; ++src
) {
1849 int s
= sources
[src
];
1851 if (s
< 0) continue;
1853 if (s
>= SSA_FIXED_MINIMUM
) continue;
1855 if (!is_live_after(ctx
, block
, ins
, s
)) {
1864 /* If a node still hasn't been killed, kill it now */
1866 for (int i
= 0; i
< nodes
; ++i
) {
1867 /* live_start == -1 most likely indicates a pinned output */
1869 if (live_end
[i
] == -1)
1873 /* Setup interference between nodes that are live at the same time */
1875 for (int i
= 0; i
< nodes
; ++i
) {
1876 for (int j
= i
+ 1; j
< nodes
; ++j
) {
1877 if (!(live_start
[i
] >= live_end
[j
] || live_start
[j
] >= live_end
[i
]))
1878 ra_add_node_interference(g
, i
, j
);
1882 ra_set_select_reg_callback(g
, midgard_ra_select_callback
, NULL
);
1884 if (!ra_allocate(g
)) {
1885 DBG("Error allocating registers\n");
1893 mir_foreach_block(ctx
, block
) {
1894 mir_foreach_instr_in_block(block
, ins
) {
1895 if (ins
->compact_branch
) continue;
1897 ssa_args args
= ins
->ssa_args
;
1899 switch (ins
->type
) {
1901 ins
->registers
.src1_reg
= dealias_register(ctx
, g
, args
.src0
, nodes
);
1903 ins
->registers
.src2_imm
= args
.inline_constant
;
1905 if (args
.inline_constant
) {
1906 /* Encode inline 16-bit constant as a vector by default */
1908 ins
->registers
.src2_reg
= ins
->inline_constant
>> 11;
1910 int lower_11
= ins
->inline_constant
& ((1 << 12) - 1);
1912 uint16_t imm
= ((lower_11
>> 8) & 0x7) | ((lower_11
& 0xFF) << 3);
1913 ins
->alu
.src2
= imm
<< 2;
1915 ins
->registers
.src2_reg
= dealias_register(ctx
, g
, args
.src1
, nodes
);
1918 ins
->registers
.out_reg
= dealias_register(ctx
, g
, args
.dest
, nodes
);
1922 case TAG_LOAD_STORE_4
: {
1923 if (OP_IS_STORE(ins
->load_store
.op
)) {
1924 /* TODO: use ssa_args for store_vary */
1925 ins
->load_store
.reg
= 0;
1927 bool has_dest
= args
.dest
>= 0;
1928 int ssa_arg
= has_dest
? args
.dest
: args
.src0
;
1930 ins
->load_store
.reg
= dealias_register(ctx
, g
, ssa_arg
, nodes
);
1943 /* Midgard IR only knows vector ALU types, but we sometimes need to actually
1944 * use scalar ALU instructions, for functional or performance reasons. To do
1945 * this, we just demote vector ALU payloads to scalar. */
1948 component_from_mask(unsigned mask
)
1950 for (int c
= 0; c
< 4; ++c
) {
1951 if (mask
& (3 << (2 * c
)))
1960 is_single_component_mask(unsigned mask
)
1964 for (int c
= 0; c
< 4; ++c
)
1965 if (mask
& (3 << (2 * c
)))
1968 return components
== 1;
1971 /* Create a mask of accessed components from a swizzle to figure out vector
1975 swizzle_to_access_mask(unsigned swizzle
)
1977 unsigned component_mask
= 0;
1979 for (int i
= 0; i
< 4; ++i
) {
1980 unsigned c
= (swizzle
>> (2 * i
)) & 3;
1981 component_mask
|= (1 << c
);
1984 return component_mask
;
1988 vector_to_scalar_source(unsigned u
)
1990 midgard_vector_alu_src v
;
1991 memcpy(&v
, &u
, sizeof(v
));
1993 midgard_scalar_alu_src s
= {
1997 .component
= (v
.swizzle
& 3) << 1
2001 memcpy(&o
, &s
, sizeof(s
));
2003 return o
& ((1 << 6) - 1);
2006 static midgard_scalar_alu
2007 vector_to_scalar_alu(midgard_vector_alu v
, midgard_instruction
*ins
)
2009 /* The output component is from the mask */
2010 midgard_scalar_alu s
= {
2012 .src1
= vector_to_scalar_source(v
.src1
),
2013 .src2
= vector_to_scalar_source(v
.src2
),
2016 .output_full
= 1, /* TODO: Half */
2017 .output_component
= component_from_mask(v
.mask
) << 1,
2020 /* Inline constant is passed along rather than trying to extract it
2023 if (ins
->ssa_args
.inline_constant
) {
2025 int lower_11
= ins
->inline_constant
& ((1 << 12) - 1);
2026 imm
|= (lower_11
>> 9) & 3;
2027 imm
|= (lower_11
>> 6) & 4;
2028 imm
|= (lower_11
>> 2) & 0x38;
2029 imm
|= (lower_11
& 63) << 6;
2037 /* Midgard prefetches instruction types, so during emission we need to
2038 * lookahead too. Unless this is the last instruction, in which we return 1. Or
2039 * if this is the second to last and the last is an ALU, then it's also 1... */
2041 #define IS_ALU(tag) (tag == TAG_ALU_4 || tag == TAG_ALU_8 || \
2042 tag == TAG_ALU_12 || tag == TAG_ALU_16)
2044 #define EMIT_AND_COUNT(type, val) util_dynarray_append(emission, type, val); \
2045 bytes_emitted += sizeof(type)
2048 emit_binary_vector_instruction(midgard_instruction
*ains
,
2049 uint16_t *register_words
, int *register_words_count
,
2050 uint64_t *body_words
, size_t *body_size
, int *body_words_count
,
2051 size_t *bytes_emitted
)
2053 memcpy(®ister_words
[(*register_words_count
)++], &ains
->registers
, sizeof(ains
->registers
));
2054 *bytes_emitted
+= sizeof(midgard_reg_info
);
2056 body_size
[*body_words_count
] = sizeof(midgard_vector_alu
);
2057 memcpy(&body_words
[(*body_words_count
)++], &ains
->alu
, sizeof(ains
->alu
));
2058 *bytes_emitted
+= sizeof(midgard_vector_alu
);
2061 /* Checks for an SSA data hazard between two adjacent instructions, keeping in
2062 * mind that we are a vector architecture and we can write to different
2063 * components simultaneously */
2066 can_run_concurrent_ssa(midgard_instruction
*first
, midgard_instruction
*second
)
2068 /* Each instruction reads some registers and writes to a register. See
2069 * where the first writes */
2071 /* Figure out where exactly we wrote to */
2072 int source
= first
->ssa_args
.dest
;
2073 int source_mask
= first
->type
== TAG_ALU_4
? squeeze_writemask(first
->alu
.mask
) : 0xF;
2075 /* As long as the second doesn't read from the first, we're okay */
2076 if (second
->ssa_args
.src0
== source
) {
2077 if (first
->type
== TAG_ALU_4
) {
2078 /* Figure out which components we just read from */
2080 int q
= second
->alu
.src1
;
2081 midgard_vector_alu_src
*m
= (midgard_vector_alu_src
*) &q
;
2083 /* Check if there are components in common, and fail if so */
2084 if (swizzle_to_access_mask(m
->swizzle
) & source_mask
)
2091 if (second
->ssa_args
.src1
== source
)
2094 /* Otherwise, it's safe in that regard. Another data hazard is both
2095 * writing to the same place, of course */
2097 if (second
->ssa_args
.dest
== source
) {
2098 /* ...but only if the components overlap */
2099 int dest_mask
= second
->type
== TAG_ALU_4
? squeeze_writemask(second
->alu
.mask
) : 0xF;
2101 if (dest_mask
& source_mask
)
2111 midgard_instruction
**segment
, unsigned segment_size
,
2112 midgard_instruction
*ains
)
2114 for (int s
= 0; s
< segment_size
; ++s
)
2115 if (!can_run_concurrent_ssa(segment
[s
], ains
))
2123 /* Schedules, but does not emit, a single basic block. After scheduling, the
2124 * final tag and size of the block are known, which are necessary for branching
2127 static midgard_bundle
2128 schedule_bundle(compiler_context
*ctx
, midgard_block
*block
, midgard_instruction
*ins
, int *skip
)
2130 int instructions_emitted
= 0, instructions_consumed
= -1;
2131 midgard_bundle bundle
= { 0 };
2133 uint8_t tag
= ins
->type
;
2135 /* Default to the instruction's tag */
2138 switch (ins
->type
) {
2140 uint32_t control
= 0;
2141 size_t bytes_emitted
= sizeof(control
);
2143 /* TODO: Constant combining */
2144 int index
= 0, last_unit
= 0;
2146 /* Previous instructions, for the purpose of parallelism */
2147 midgard_instruction
*segment
[4] = {0};
2148 int segment_size
= 0;
2150 instructions_emitted
= -1;
2151 midgard_instruction
*pins
= ins
;
2154 midgard_instruction
*ains
= pins
;
2156 /* Advance instruction pointer */
2158 ains
= mir_next_op(pins
);
2162 /* Out-of-work condition */
2163 if ((struct list_head
*) ains
== &block
->instructions
)
2166 /* Ensure that the chain can continue */
2167 if (ains
->type
!= TAG_ALU_4
) break;
2169 /* According to the presentation "The ARM
2170 * Mali-T880 Mobile GPU" from HotChips 27,
2171 * there are two pipeline stages. Branching
2172 * position determined experimentally. Lines
2173 * are executed in parallel:
2176 * [ VADD ] [ SMUL ] [ LUT ] [ BRANCH ]
2178 * Verify that there are no ordering dependencies here.
2180 * TODO: Allow for parallelism!!!
2183 /* Pick a unit for it if it doesn't force a particular unit */
2185 int unit
= ains
->unit
;
2188 int op
= ains
->alu
.op
;
2189 int units
= alu_opcode_props
[op
];
2191 /* TODO: Promotion of scalars to vectors */
2192 int vector
= ((!is_single_component_mask(ains
->alu
.mask
)) || ((units
& UNITS_SCALAR
) == 0)) && (units
& UNITS_ANY_VECTOR
);
2195 assert(units
& UNITS_SCALAR
);
2198 if (last_unit
>= UNIT_VADD
) {
2199 if (units
& UNIT_VLUT
)
2204 if ((units
& UNIT_VMUL
) && !(control
& UNIT_VMUL
))
2206 else if ((units
& UNIT_VADD
) && !(control
& UNIT_VADD
))
2208 else if (units
& UNIT_VLUT
)
2214 if (last_unit
>= UNIT_VADD
) {
2215 if ((units
& UNIT_SMUL
) && !(control
& UNIT_SMUL
))
2217 else if (units
& UNIT_VLUT
)
2222 if ((units
& UNIT_SADD
) && !(control
& UNIT_SADD
) && !midgard_has_hazard(segment
, segment_size
, ains
))
2224 else if (units
& UNIT_SMUL
)
2225 unit
= ((units
& UNIT_VMUL
) && !(control
& UNIT_VMUL
)) ? UNIT_VMUL
: UNIT_SMUL
;
2226 else if ((units
& UNIT_VADD
) && !(control
& UNIT_VADD
))
2233 assert(unit
& units
);
2236 /* Late unit check, this time for encoding (not parallelism) */
2237 if (unit
<= last_unit
) break;
2239 /* Clear the segment */
2240 if (last_unit
< UNIT_VADD
&& unit
>= UNIT_VADD
)
2243 if (midgard_has_hazard(segment
, segment_size
, ains
))
2246 /* We're good to go -- emit the instruction */
2249 segment
[segment_size
++] = ains
;
2251 /* Only one set of embedded constants per
2252 * bundle possible; if we have more, we must
2253 * break the chain early, unfortunately */
2255 if (ains
->has_constants
) {
2256 if (bundle
.has_embedded_constants
) {
2257 /* ...but if there are already
2258 * constants but these are the
2259 * *same* constants, we let it
2262 if (memcmp(bundle
.constants
, ains
->constants
, sizeof(bundle
.constants
)))
2265 bundle
.has_embedded_constants
= true;
2266 memcpy(bundle
.constants
, ains
->constants
, sizeof(bundle
.constants
));
2268 /* If this is a blend shader special constant, track it for patching */
2269 if (ains
->has_blend_constant
)
2270 bundle
.has_blend_constant
= true;
2274 if (ains
->unit
& UNITS_ANY_VECTOR
) {
2275 emit_binary_vector_instruction(ains
, bundle
.register_words
,
2276 &bundle
.register_words_count
, bundle
.body_words
,
2277 bundle
.body_size
, &bundle
.body_words_count
, &bytes_emitted
);
2278 } else if (ains
->compact_branch
) {
2279 /* All of r0 has to be written out
2280 * along with the branch writeout.
2283 if (ains
->writeout
) {
2285 midgard_instruction ins
= v_fmov(0, blank_alu_src
, SSA_FIXED_REGISTER(0));
2286 ins
.unit
= UNIT_VMUL
;
2288 control
|= ins
.unit
;
2290 emit_binary_vector_instruction(&ins
, bundle
.register_words
,
2291 &bundle
.register_words_count
, bundle
.body_words
,
2292 bundle
.body_size
, &bundle
.body_words_count
, &bytes_emitted
);
2294 /* Analyse the group to see if r0 is written in full, on-time, without hanging dependencies*/
2295 bool written_late
= false;
2296 bool components
[4] = { 0 };
2297 uint16_t register_dep_mask
= 0;
2298 uint16_t written_mask
= 0;
2300 midgard_instruction
*qins
= ins
;
2301 for (int t
= 0; t
< index
; ++t
) {
2302 if (qins
->registers
.out_reg
!= 0) {
2303 /* Mark down writes */
2305 written_mask
|= (1 << qins
->registers
.out_reg
);
2307 /* Mark down the register dependencies for errata check */
2309 if (qins
->registers
.src1_reg
< 16)
2310 register_dep_mask
|= (1 << qins
->registers
.src1_reg
);
2312 if (qins
->registers
.src2_reg
< 16)
2313 register_dep_mask
|= (1 << qins
->registers
.src2_reg
);
2315 int mask
= qins
->alu
.mask
;
2317 for (int c
= 0; c
< 4; ++c
)
2318 if (mask
& (0x3 << (2 * c
)))
2319 components
[c
] = true;
2321 /* ..but if the writeout is too late, we have to break up anyway... for some reason */
2323 if (qins
->unit
== UNIT_VLUT
)
2324 written_late
= true;
2327 /* Advance instruction pointer */
2328 qins
= mir_next_op(qins
);
2332 /* ERRATA (?): In a bundle ending in a fragment writeout, the register dependencies of r0 cannot be written within this bundle (discovered in -bshading:shading=phong) */
2333 if (register_dep_mask
& written_mask
) {
2334 DBG("ERRATA WORKAROUND: Breakup for writeout dependency masks %X vs %X (common %X)\n", register_dep_mask
, written_mask
, register_dep_mask
& written_mask
);
2341 /* If even a single component is not written, break it up (conservative check). */
2342 bool breakup
= false;
2344 for (int c
= 0; c
< 4; ++c
)
2351 /* Otherwise, we're free to proceed */
2355 if (ains
->unit
== ALU_ENAB_BRANCH
) {
2356 bundle
.body_size
[bundle
.body_words_count
] = sizeof(midgard_branch_extended
);
2357 memcpy(&bundle
.body_words
[bundle
.body_words_count
++], &ains
->branch_extended
, sizeof(midgard_branch_extended
));
2358 bytes_emitted
+= sizeof(midgard_branch_extended
);
2360 bundle
.body_size
[bundle
.body_words_count
] = sizeof(ains
->br_compact
);
2361 memcpy(&bundle
.body_words
[bundle
.body_words_count
++], &ains
->br_compact
, sizeof(ains
->br_compact
));
2362 bytes_emitted
+= sizeof(ains
->br_compact
);
2365 memcpy(&bundle
.register_words
[bundle
.register_words_count
++], &ains
->registers
, sizeof(ains
->registers
));
2366 bytes_emitted
+= sizeof(midgard_reg_info
);
2368 bundle
.body_size
[bundle
.body_words_count
] = sizeof(midgard_scalar_alu
);
2369 bundle
.body_words_count
++;
2370 bytes_emitted
+= sizeof(midgard_scalar_alu
);
2373 /* Defer marking until after writing to allow for break */
2374 control
|= ains
->unit
;
2375 last_unit
= ains
->unit
;
2376 ++instructions_emitted
;
2380 /* Bubble up the number of instructions for skipping */
2381 instructions_consumed
= index
- 1;
2385 /* Pad ALU op to nearest word */
2387 if (bytes_emitted
& 15) {
2388 padding
= 16 - (bytes_emitted
& 15);
2389 bytes_emitted
+= padding
;
2392 /* Constants must always be quadwords */
2393 if (bundle
.has_embedded_constants
)
2394 bytes_emitted
+= 16;
2396 /* Size ALU instruction for tag */
2397 bundle
.tag
= (TAG_ALU_4
) + (bytes_emitted
/ 16) - 1;
2398 bundle
.padding
= padding
;
2399 bundle
.control
= bundle
.tag
| control
;
2404 case TAG_LOAD_STORE_4
: {
2405 /* Load store instructions have two words at once. If
2406 * we only have one queued up, we need to NOP pad.
2407 * Otherwise, we store both in succession to save space
2408 * and cycles -- letting them go in parallel -- skip
2409 * the next. The usefulness of this optimisation is
2410 * greatly dependent on the quality of the instruction
2414 midgard_instruction
*next_op
= mir_next_op(ins
);
2416 if ((struct list_head
*) next_op
!= &block
->instructions
&& next_op
->type
== TAG_LOAD_STORE_4
) {
2417 /* As the two operate concurrently, make sure
2418 * they are not dependent */
2420 if (can_run_concurrent_ssa(ins
, next_op
) || true) {
2421 /* Skip ahead, since it's redundant with the pair */
2422 instructions_consumed
= 1 + (instructions_emitted
++);
2430 /* Texture ops default to single-op-per-bundle scheduling */
2434 /* Copy the instructions into the bundle */
2435 bundle
.instruction_count
= instructions_emitted
+ 1;
2439 midgard_instruction
*uins
= ins
;
2440 for (int i
= 0; used_idx
< bundle
.instruction_count
; ++i
) {
2441 bundle
.instructions
[used_idx
++] = *uins
;
2442 uins
= mir_next_op(uins
);
2445 *skip
= (instructions_consumed
== -1) ? instructions_emitted
: instructions_consumed
;
2451 quadword_size(int tag
)
2466 case TAG_LOAD_STORE_4
:
2478 /* Schedule a single block by iterating its instruction to create bundles.
2479 * While we go, tally about the bundle sizes to compute the block size. */
2482 schedule_block(compiler_context
*ctx
, midgard_block
*block
)
2484 util_dynarray_init(&block
->bundles
, NULL
);
2486 block
->quadword_count
= 0;
2488 mir_foreach_instr_in_block(block
, ins
) {
2490 midgard_bundle bundle
= schedule_bundle(ctx
, block
, ins
, &skip
);
2491 util_dynarray_append(&block
->bundles
, midgard_bundle
, bundle
);
2493 if (bundle
.has_blend_constant
) {
2494 /* TODO: Multiblock? */
2495 int quadwords_within_block
= block
->quadword_count
+ quadword_size(bundle
.tag
) - 1;
2496 ctx
->blend_constant_offset
= quadwords_within_block
* 0x10;
2500 ins
= mir_next_op(ins
);
2502 block
->quadword_count
+= quadword_size(bundle
.tag
);
2505 block
->is_scheduled
= true;
2509 schedule_program(compiler_context
*ctx
)
2511 allocate_registers(ctx
);
2513 mir_foreach_block(ctx
, block
) {
2514 schedule_block(ctx
, block
);
2518 /* After everything is scheduled, emit whole bundles at a time */
2521 emit_binary_bundle(compiler_context
*ctx
, midgard_bundle
*bundle
, struct util_dynarray
*emission
, int next_tag
)
2523 int lookahead
= next_tag
<< 4;
2525 switch (bundle
->tag
) {
2530 /* Actually emit each component */
2531 util_dynarray_append(emission
, uint32_t, bundle
->control
| lookahead
);
2533 for (int i
= 0; i
< bundle
->register_words_count
; ++i
)
2534 util_dynarray_append(emission
, uint16_t, bundle
->register_words
[i
]);
2536 /* Emit body words based on the instructions bundled */
2537 for (int i
= 0; i
< bundle
->instruction_count
; ++i
) {
2538 midgard_instruction
*ins
= &bundle
->instructions
[i
];
2540 if (ins
->unit
& UNITS_ANY_VECTOR
) {
2541 memcpy(util_dynarray_grow(emission
, sizeof(midgard_vector_alu
)), &ins
->alu
, sizeof(midgard_vector_alu
));
2542 } else if (ins
->compact_branch
) {
2543 /* Dummy move, XXX DRY */
2544 if ((i
== 0) && ins
->writeout
) {
2545 midgard_instruction ins
= v_fmov(0, blank_alu_src
, SSA_FIXED_REGISTER(0));
2546 memcpy(util_dynarray_grow(emission
, sizeof(midgard_vector_alu
)), &ins
.alu
, sizeof(midgard_vector_alu
));
2549 if (ins
->unit
== ALU_ENAB_BR_COMPACT
) {
2550 memcpy(util_dynarray_grow(emission
, sizeof(ins
->br_compact
)), &ins
->br_compact
, sizeof(ins
->br_compact
));
2552 memcpy(util_dynarray_grow(emission
, sizeof(ins
->branch_extended
)), &ins
->branch_extended
, sizeof(ins
->branch_extended
));
2556 midgard_scalar_alu scalarised
= vector_to_scalar_alu(ins
->alu
, ins
);
2557 memcpy(util_dynarray_grow(emission
, sizeof(scalarised
)), &scalarised
, sizeof(scalarised
));
2561 /* Emit padding (all zero) */
2562 memset(util_dynarray_grow(emission
, bundle
->padding
), 0, bundle
->padding
);
2564 /* Tack on constants */
2566 if (bundle
->has_embedded_constants
) {
2567 util_dynarray_append(emission
, float, bundle
->constants
[0]);
2568 util_dynarray_append(emission
, float, bundle
->constants
[1]);
2569 util_dynarray_append(emission
, float, bundle
->constants
[2]);
2570 util_dynarray_append(emission
, float, bundle
->constants
[3]);
2576 case TAG_LOAD_STORE_4
: {
2577 /* One or two composing instructions */
2579 uint64_t current64
, next64
= LDST_NOP
;
2581 memcpy(¤t64
, &bundle
->instructions
[0].load_store
, sizeof(current64
));
2583 if (bundle
->instruction_count
== 2)
2584 memcpy(&next64
, &bundle
->instructions
[1].load_store
, sizeof(next64
));
2586 midgard_load_store instruction
= {
2587 .type
= bundle
->tag
,
2588 .next_type
= next_tag
,
2593 util_dynarray_append(emission
, midgard_load_store
, instruction
);
2598 case TAG_TEXTURE_4
: {
2599 /* Texture instructions are easy, since there is no
2600 * pipelining nor VLIW to worry about. We may need to set the .last flag */
2602 midgard_instruction
*ins
= &bundle
->instructions
[0];
2604 ins
->texture
.type
= TAG_TEXTURE_4
;
2605 ins
->texture
.next_type
= next_tag
;
2607 ctx
->texture_op_count
--;
2609 if (!ctx
->texture_op_count
) {
2610 ins
->texture
.cont
= 0;
2611 ins
->texture
.last
= 1;
2614 util_dynarray_append(emission
, midgard_texture_word
, ins
->texture
);
2619 DBG("Unknown midgard instruction type\n");
2626 /* ALU instructions can inline or embed constants, which decreases register
2627 * pressure and saves space. */
2629 #define CONDITIONAL_ATTACH(src) { \
2630 void *entry = _mesa_hash_table_u64_search(ctx->ssa_constants, alu->ssa_args.src + 1); \
2633 attach_constants(ctx, alu, entry, alu->ssa_args.src + 1); \
2634 alu->ssa_args.src = SSA_FIXED_REGISTER(REGISTER_CONSTANT); \
2639 inline_alu_constants(compiler_context
*ctx
)
2641 mir_foreach_instr(ctx
, alu
) {
2642 /* Other instructions cannot inline constants */
2643 if (alu
->type
!= TAG_ALU_4
) continue;
2645 /* If there is already a constant here, we can do nothing */
2646 if (alu
->has_constants
) continue;
2648 CONDITIONAL_ATTACH(src0
);
2650 if (!alu
->has_constants
) {
2651 CONDITIONAL_ATTACH(src1
)
2652 } else if (!alu
->inline_constant
) {
2653 /* Corner case: _two_ vec4 constants, for instance with a
2654 * csel. For this case, we can only use a constant
2655 * register for one, we'll have to emit a move for the
2656 * other. Note, if both arguments are constants, then
2657 * necessarily neither argument depends on the value of
2658 * any particular register. As the destination register
2659 * will be wiped, that means we can spill the constant
2660 * to the destination register.
2663 void *entry
= _mesa_hash_table_u64_search(ctx
->ssa_constants
, alu
->ssa_args
.src1
+ 1);
2664 unsigned scratch
= alu
->ssa_args
.dest
;
2667 midgard_instruction ins
= v_fmov(SSA_FIXED_REGISTER(REGISTER_CONSTANT
), blank_alu_src
, scratch
);
2668 attach_constants(ctx
, &ins
, entry
, alu
->ssa_args
.src1
+ 1);
2670 /* Force a break XXX Defer r31 writes */
2671 ins
.unit
= UNIT_VLUT
;
2673 /* Set the source */
2674 alu
->ssa_args
.src1
= scratch
;
2676 /* Inject us -before- the last instruction which set r31 */
2677 mir_insert_instruction_before(mir_prev_op(alu
), ins
);
2683 /* Midgard supports two types of constants, embedded constants (128-bit) and
2684 * inline constants (16-bit). Sometimes, especially with scalar ops, embedded
2685 * constants can be demoted to inline constants, for space savings and
2686 * sometimes a performance boost */
2689 embedded_to_inline_constant(compiler_context
*ctx
)
2691 mir_foreach_instr(ctx
, ins
) {
2692 if (!ins
->has_constants
) continue;
2694 if (ins
->ssa_args
.inline_constant
) continue;
2696 /* Blend constants must not be inlined by definition */
2697 if (ins
->has_blend_constant
) continue;
2699 /* src1 cannot be an inline constant due to encoding
2700 * restrictions. So, if possible we try to flip the arguments
2703 int op
= ins
->alu
.op
;
2705 if (ins
->ssa_args
.src0
== SSA_FIXED_REGISTER(REGISTER_CONSTANT
)) {
2706 /* Flip based on op. Fallthrough intentional */
2709 /* These ops require an operational change to flip their arguments TODO */
2710 case midgard_alu_op_flt
:
2711 case midgard_alu_op_fle
:
2712 case midgard_alu_op_ilt
:
2713 case midgard_alu_op_ile
:
2714 case midgard_alu_op_fcsel
:
2715 case midgard_alu_op_icsel
:
2716 case midgard_alu_op_isub
:
2717 DBG("Missed non-commutative flip (%s)\n", alu_opcode_names
[op
]);
2720 /* These ops are commutative and Just Flip */
2721 case midgard_alu_op_fne
:
2722 case midgard_alu_op_fadd
:
2723 case midgard_alu_op_fmul
:
2724 case midgard_alu_op_fmin
:
2725 case midgard_alu_op_fmax
:
2726 case midgard_alu_op_iadd
:
2727 case midgard_alu_op_imul
:
2728 case midgard_alu_op_feq
:
2729 case midgard_alu_op_ieq
:
2730 case midgard_alu_op_ine
:
2731 case midgard_alu_op_iand
:
2732 case midgard_alu_op_ior
:
2733 case midgard_alu_op_ixor
:
2734 /* Flip the SSA numbers */
2735 ins
->ssa_args
.src0
= ins
->ssa_args
.src1
;
2736 ins
->ssa_args
.src1
= SSA_FIXED_REGISTER(REGISTER_CONSTANT
);
2738 /* And flip the modifiers */
2742 src_temp
= ins
->alu
.src2
;
2743 ins
->alu
.src2
= ins
->alu
.src1
;
2744 ins
->alu
.src1
= src_temp
;
2751 if (ins
->ssa_args
.src1
== SSA_FIXED_REGISTER(REGISTER_CONSTANT
)) {
2752 /* Extract the source information */
2754 midgard_vector_alu_src
*src
;
2755 int q
= ins
->alu
.src2
;
2756 midgard_vector_alu_src
*m
= (midgard_vector_alu_src
*) &q
;
2759 /* Component is from the swizzle, e.g. r26.w -> w component. TODO: What if x is masked out? */
2760 int component
= src
->swizzle
& 3;
2762 /* Scale constant appropriately, if we can legally */
2763 uint16_t scaled_constant
= 0;
2765 /* XXX: Check legality */
2766 if (midgard_is_integer_op(op
)) {
2767 /* TODO: Inline integer */
2770 unsigned int *iconstants
= (unsigned int *) ins
->constants
;
2771 scaled_constant
= (uint16_t) iconstants
[component
];
2773 /* Constant overflow after resize */
2774 if (scaled_constant
!= iconstants
[component
])
2777 scaled_constant
= _mesa_float_to_half((float) ins
->constants
[component
]);
2780 /* We don't know how to handle these with a constant */
2782 if (src
->abs
|| src
->negate
|| src
->half
|| src
->rep_low
|| src
->rep_high
) {
2783 DBG("Bailing inline constant...\n");
2787 /* Make sure that the constant is not itself a
2788 * vector by checking if all accessed values
2789 * (by the swizzle) are the same. */
2791 uint32_t *cons
= (uint32_t *) ins
->constants
;
2792 uint32_t value
= cons
[component
];
2794 bool is_vector
= false;
2795 unsigned mask
= effective_writemask(&ins
->alu
);
2797 for (int c
= 1; c
< 4; ++c
) {
2798 /* We only care if this component is actually used */
2799 if (!(mask
& (1 << c
)))
2802 uint32_t test
= cons
[(src
->swizzle
>> (2 * c
)) & 3];
2804 if (test
!= value
) {
2813 /* Get rid of the embedded constant */
2814 ins
->has_constants
= false;
2815 ins
->ssa_args
.src1
= SSA_UNUSED_0
;
2816 ins
->ssa_args
.inline_constant
= true;
2817 ins
->inline_constant
= scaled_constant
;
2822 /* Map normal SSA sources to other SSA sources / fixed registers (like
2826 map_ssa_to_alias(compiler_context
*ctx
, int *ref
)
2828 unsigned int alias
= (uintptr_t) _mesa_hash_table_u64_search(ctx
->ssa_to_alias
, *ref
+ 1);
2831 /* Remove entry in leftovers to avoid a redunant fmov */
2833 struct set_entry
*leftover
= _mesa_set_search(ctx
->leftover_ssa_to_alias
, ((void *) (uintptr_t) (*ref
+ 1)));
2836 _mesa_set_remove(ctx
->leftover_ssa_to_alias
, leftover
);
2838 /* Assign the alias map */
2844 #define AS_SRC(to, u) \
2845 int q##to = ins->alu.src2; \
2846 midgard_vector_alu_src *to = (midgard_vector_alu_src *) &q##to;
2848 /* Removing unused moves is necessary to clean up the texture pipeline results.
2850 * To do so, we find moves in the MIR. We check if their destination is live later. If it's not, the move is redundant. */
2853 midgard_eliminate_orphan_moves(compiler_context
*ctx
, midgard_block
*block
)
2855 mir_foreach_instr_in_block_safe(block
, ins
) {
2856 if (ins
->type
!= TAG_ALU_4
) continue;
2858 if (ins
->alu
.op
!= midgard_alu_op_fmov
) continue;
2860 if (ins
->ssa_args
.dest
>= SSA_FIXED_MINIMUM
) continue;
2862 if (midgard_is_pinned(ctx
, ins
->ssa_args
.dest
)) continue;
2864 if (is_live_after(ctx
, block
, ins
, ins
->ssa_args
.dest
)) continue;
2866 mir_remove_instruction(ins
);
2870 /* The following passes reorder MIR instructions to enable better scheduling */
2873 midgard_pair_load_store(compiler_context
*ctx
, midgard_block
*block
)
2875 mir_foreach_instr_in_block_safe(block
, ins
) {
2876 if (ins
->type
!= TAG_LOAD_STORE_4
) continue;
2878 /* We've found a load/store op. Check if next is also load/store. */
2879 midgard_instruction
*next_op
= mir_next_op(ins
);
2880 if (&next_op
->link
!= &block
->instructions
) {
2881 if (next_op
->type
== TAG_LOAD_STORE_4
) {
2882 /* If so, we're done since we're a pair */
2883 ins
= mir_next_op(ins
);
2887 /* Maximum search distance to pair, to avoid register pressure disasters */
2888 int search_distance
= 8;
2890 /* Otherwise, we have an orphaned load/store -- search for another load */
2891 mir_foreach_instr_in_block_from(block
, c
, mir_next_op(ins
)) {
2892 /* Terminate search if necessary */
2893 if (!(search_distance
--)) break;
2895 if (c
->type
!= TAG_LOAD_STORE_4
) continue;
2897 if (OP_IS_STORE(c
->load_store
.op
)) continue;
2899 /* We found one! Move it up to pair and remove it from the old location */
2901 mir_insert_instruction_before(ins
, *c
);
2902 mir_remove_instruction(c
);
2910 /* Emit varying stores late */
2913 midgard_emit_store(compiler_context
*ctx
, midgard_block
*block
) {
2914 /* Iterate in reverse to get the final write, rather than the first */
2916 mir_foreach_instr_in_block_safe_rev(block
, ins
) {
2917 /* Check if what we just wrote needs a store */
2918 int idx
= ins
->ssa_args
.dest
;
2919 uintptr_t varying
= ((uintptr_t) _mesa_hash_table_u64_search(ctx
->ssa_varyings
, idx
+ 1));
2921 if (!varying
) continue;
2925 /* We need to store to the appropriate varying, so emit the
2928 /* TODO: Integrate with special purpose RA (and scheduler?) */
2929 bool high_varying_register
= false;
2931 midgard_instruction mov
= v_fmov(idx
, blank_alu_src
, SSA_FIXED_REGISTER(REGISTER_VARYING_BASE
+ high_varying_register
));
2933 midgard_instruction st
= m_store_vary_32(SSA_FIXED_REGISTER(high_varying_register
), varying
);
2934 st
.load_store
.unknown
= 0x1E9E; /* XXX: What is this? */
2936 mir_insert_instruction_before(mir_next_op(ins
), st
);
2937 mir_insert_instruction_before(mir_next_op(ins
), mov
);
2939 /* We no longer need to store this varying */
2940 _mesa_hash_table_u64_remove(ctx
->ssa_varyings
, idx
+ 1);
2944 /* If there are leftovers after the below pass, emit actual fmov
2945 * instructions for the slow-but-correct path */
2948 emit_leftover_move(compiler_context
*ctx
)
2950 set_foreach(ctx
->leftover_ssa_to_alias
, leftover
) {
2951 int base
= ((uintptr_t) leftover
->key
) - 1;
2954 map_ssa_to_alias(ctx
, &mapped
);
2955 EMIT(fmov
, mapped
, blank_alu_src
, base
);
2960 actualise_ssa_to_alias(compiler_context
*ctx
)
2962 mir_foreach_instr(ctx
, ins
) {
2963 map_ssa_to_alias(ctx
, &ins
->ssa_args
.src0
);
2964 map_ssa_to_alias(ctx
, &ins
->ssa_args
.src1
);
2967 emit_leftover_move(ctx
);
2970 /* Vertex shaders do not write gl_Position as is; instead, they write a
2971 * transformed screen space position as a varying. See section 12.5 "Coordinate
2972 * Transformation" of the ES 3.2 full specification for details.
2974 * This transformation occurs early on, as NIR and prior to optimisation, in
2975 * order to take advantage of NIR optimisation passes of the transform itself.
2979 write_transformed_position(nir_builder
*b
, nir_src input_point_src
, int uniform_no
)
2981 nir_ssa_def
*input_point
= nir_ssa_for_src(b
, input_point_src
, 4);
2983 /* Get viewport from the uniforms */
2984 nir_intrinsic_instr
*load
;
2985 load
= nir_intrinsic_instr_create(b
->shader
, nir_intrinsic_load_uniform
);
2986 load
->num_components
= 4;
2987 load
->src
[0] = nir_src_for_ssa(nir_imm_int(b
, uniform_no
));
2988 nir_ssa_dest_init(&load
->instr
, &load
->dest
, 4, 32, NULL
);
2989 nir_builder_instr_insert(b
, &load
->instr
);
2991 /* Formatted as <width, height, centerx, centery> */
2992 nir_ssa_def
*viewport_vec4
= &load
->dest
.ssa
;
2993 nir_ssa_def
*viewport_width_2
= nir_channel(b
, viewport_vec4
, 0);
2994 nir_ssa_def
*viewport_height_2
= nir_channel(b
, viewport_vec4
, 1);
2995 nir_ssa_def
*viewport_offset
= nir_channels(b
, viewport_vec4
, 0x8 | 0x4);
2997 /* XXX: From uniforms? */
2998 nir_ssa_def
*depth_near
= nir_imm_float(b
, 0.0);
2999 nir_ssa_def
*depth_far
= nir_imm_float(b
, 1.0);
3001 /* World space to normalised device coordinates */
3003 nir_ssa_def
*w_recip
= nir_frcp(b
, nir_channel(b
, input_point
, 3));
3004 nir_ssa_def
*ndc_point
= nir_fmul(b
, nir_channels(b
, input_point
, 0x7), w_recip
);
3006 /* Normalised device coordinates to screen space */
3008 nir_ssa_def
*viewport_multiplier
= nir_vec2(b
, viewport_width_2
, viewport_height_2
);
3009 nir_ssa_def
*viewport_xy
= nir_fadd(b
, nir_fmul(b
, nir_channels(b
, ndc_point
, 0x3), viewport_multiplier
), viewport_offset
);
3011 nir_ssa_def
*depth_multiplier
= nir_fmul(b
, nir_fsub(b
, depth_far
, depth_near
), nir_imm_float(b
, 0.5f
));
3012 nir_ssa_def
*depth_offset
= nir_fmul(b
, nir_fadd(b
, depth_far
, depth_near
), nir_imm_float(b
, 0.5f
));
3013 nir_ssa_def
*screen_depth
= nir_fadd(b
, nir_fmul(b
, nir_channel(b
, ndc_point
, 2), depth_multiplier
), depth_offset
);
3015 /* gl_Position will be written out in screenspace xyz, with w set to
3016 * the reciprocal we computed earlier. The transformed w component is
3017 * then used for perspective-correct varying interpolation. The
3018 * transformed w component must preserve its original sign; this is
3019 * used in depth clipping computations */
3021 nir_ssa_def
*screen_space
= nir_vec4(b
,
3022 nir_channel(b
, viewport_xy
, 0),
3023 nir_channel(b
, viewport_xy
, 1),
3027 /* Finally, write out the transformed values to the varying */
3029 nir_intrinsic_instr
*store
;
3030 store
= nir_intrinsic_instr_create(b
->shader
, nir_intrinsic_store_output
);
3031 store
->num_components
= 4;
3032 nir_intrinsic_set_base(store
, 0);
3033 nir_intrinsic_set_write_mask(store
, 0xf);
3034 store
->src
[0].ssa
= screen_space
;
3035 store
->src
[0].is_ssa
= true;
3036 store
->src
[1] = nir_src_for_ssa(nir_imm_int(b
, 0));
3037 nir_builder_instr_insert(b
, &store
->instr
);
3041 transform_position_writes(nir_shader
*shader
)
3043 nir_foreach_function(func
, shader
) {
3044 nir_foreach_block(block
, func
->impl
) {
3045 nir_foreach_instr_safe(instr
, block
) {
3046 if (instr
->type
!= nir_instr_type_intrinsic
) continue;
3048 nir_intrinsic_instr
*intr
= nir_instr_as_intrinsic(instr
);
3049 nir_variable
*out
= NULL
;
3051 switch (intr
->intrinsic
) {
3052 case nir_intrinsic_store_output
:
3053 /* already had i/o lowered.. lookup the matching output var: */
3054 nir_foreach_variable(var
, &shader
->outputs
) {
3055 int drvloc
= var
->data
.driver_location
;
3057 if (nir_intrinsic_base(intr
) == drvloc
) {
3071 if (out
->data
.mode
!= nir_var_shader_out
)
3074 if (out
->data
.location
!= VARYING_SLOT_POS
)
3078 nir_builder_init(&b
, func
->impl
);
3079 b
.cursor
= nir_before_instr(instr
);
3081 write_transformed_position(&b
, intr
->src
[0], UNIFORM_VIEWPORT
);
3082 nir_instr_remove(instr
);
3089 emit_fragment_epilogue(compiler_context
*ctx
)
3091 /* Special case: writing out constants requires us to include the move
3092 * explicitly now, so shove it into r0 */
3094 void *constant_value
= _mesa_hash_table_u64_search(ctx
->ssa_constants
, ctx
->fragment_output
+ 1);
3096 if (constant_value
) {
3097 midgard_instruction ins
= v_fmov(SSA_FIXED_REGISTER(REGISTER_CONSTANT
), blank_alu_src
, SSA_FIXED_REGISTER(0));
3098 attach_constants(ctx
, &ins
, constant_value
, ctx
->fragment_output
+ 1);
3099 emit_mir_instruction(ctx
, ins
);
3102 /* Perform the actual fragment writeout. We have two writeout/branch
3103 * instructions, forming a loop until writeout is successful as per the
3104 * docs. TODO: gl_FragDepth */
3106 EMIT(alu_br_compact_cond
, midgard_jmp_writeout_op_writeout
, TAG_ALU_4
, 0, midgard_condition_always
);
3107 EMIT(alu_br_compact_cond
, midgard_jmp_writeout_op_writeout
, TAG_ALU_4
, -1, midgard_condition_always
);
3110 /* For the blend epilogue, we need to convert the blended fragment vec4 (stored
3111 * in r0) to a RGBA8888 value by scaling and type converting. We then output it
3112 * with the int8 analogue to the fragment epilogue */
3115 emit_blend_epilogue(compiler_context
*ctx
)
3117 /* vmul.fmul.none.fulllow hr48, r0, #255 */
3119 midgard_instruction scale
= {
3122 .inline_constant
= _mesa_float_to_half(255.0),
3124 .src0
= SSA_FIXED_REGISTER(0),
3125 .src1
= SSA_UNUSED_0
,
3126 .dest
= SSA_FIXED_REGISTER(24),
3127 .inline_constant
= true
3130 .op
= midgard_alu_op_fmul
,
3131 .reg_mode
= midgard_reg_mode_full
,
3132 .dest_override
= midgard_dest_override_lower
,
3134 .src1
= vector_alu_srco_unsigned(blank_alu_src
),
3135 .src2
= vector_alu_srco_unsigned(blank_alu_src
),
3139 emit_mir_instruction(ctx
, scale
);
3141 /* vadd.f2u8.pos.low hr0, hr48, #0 */
3143 midgard_vector_alu_src alu_src
= blank_alu_src
;
3144 alu_src
.half
= true;
3146 midgard_instruction f2u8
= {
3149 .src0
= SSA_FIXED_REGISTER(24),
3150 .src1
= SSA_UNUSED_0
,
3151 .dest
= SSA_FIXED_REGISTER(0),
3152 .inline_constant
= true
3155 .op
= midgard_alu_op_f2u8
,
3156 .reg_mode
= midgard_reg_mode_half
,
3157 .dest_override
= midgard_dest_override_lower
,
3158 .outmod
= midgard_outmod_pos
,
3160 .src1
= vector_alu_srco_unsigned(alu_src
),
3161 .src2
= vector_alu_srco_unsigned(blank_alu_src
),
3165 emit_mir_instruction(ctx
, f2u8
);
3167 /* vmul.imov.quarter r0, r0, r0 */
3169 midgard_instruction imov_8
= {
3172 .src0
= SSA_UNUSED_1
,
3173 .src1
= SSA_FIXED_REGISTER(0),
3174 .dest
= SSA_FIXED_REGISTER(0),
3177 .op
= midgard_alu_op_imov
,
3178 .reg_mode
= midgard_reg_mode_quarter
,
3179 .dest_override
= midgard_dest_override_none
,
3181 .src1
= vector_alu_srco_unsigned(blank_alu_src
),
3182 .src2
= vector_alu_srco_unsigned(blank_alu_src
),
3186 /* Emit branch epilogue with the 8-bit move as the source */
3188 emit_mir_instruction(ctx
, imov_8
);
3189 EMIT(alu_br_compact_cond
, midgard_jmp_writeout_op_writeout
, TAG_ALU_4
, 0, midgard_condition_always
);
3191 emit_mir_instruction(ctx
, imov_8
);
3192 EMIT(alu_br_compact_cond
, midgard_jmp_writeout_op_writeout
, TAG_ALU_4
, -1, midgard_condition_always
);
3195 static midgard_block
*
3196 emit_block(compiler_context
*ctx
, nir_block
*block
)
3198 midgard_block
*this_block
= malloc(sizeof(midgard_block
));
3199 list_addtail(&this_block
->link
, &ctx
->blocks
);
3201 this_block
->is_scheduled
= false;
3204 ctx
->texture_index
[0] = -1;
3205 ctx
->texture_index
[1] = -1;
3207 /* Set up current block */
3208 list_inithead(&this_block
->instructions
);
3209 ctx
->current_block
= this_block
;
3211 nir_foreach_instr(instr
, block
) {
3212 emit_instr(ctx
, instr
);
3213 ++ctx
->instruction_count
;
3216 inline_alu_constants(ctx
);
3217 embedded_to_inline_constant(ctx
);
3219 /* Perform heavylifting for aliasing */
3220 actualise_ssa_to_alias(ctx
);
3222 midgard_emit_store(ctx
, this_block
);
3223 midgard_eliminate_orphan_moves(ctx
, this_block
);
3224 midgard_pair_load_store(ctx
, this_block
);
3226 /* Append fragment shader epilogue (value writeout) */
3227 if (ctx
->stage
== MESA_SHADER_FRAGMENT
) {
3228 if (block
== nir_impl_last_block(ctx
->func
->impl
)) {
3230 emit_blend_epilogue(ctx
);
3232 emit_fragment_epilogue(ctx
);
3236 /* Fallthrough save */
3237 this_block
->next_fallthrough
= ctx
->previous_source_block
;
3239 if (block
== nir_start_block(ctx
->func
->impl
))
3240 ctx
->initial_block
= this_block
;
3242 if (block
== nir_impl_last_block(ctx
->func
->impl
))
3243 ctx
->final_block
= this_block
;
3245 /* Allow the next control flow to access us retroactively, for
3247 ctx
->current_block
= this_block
;
3249 /* Document the fallthrough chain */
3250 ctx
->previous_source_block
= this_block
;
3255 static midgard_block
*emit_cf_list(struct compiler_context
*ctx
, struct exec_list
*list
);
3258 emit_if(struct compiler_context
*ctx
, nir_if
*nif
)
3260 /* Conditional branches expect the condition in r31.w; emit a move for
3261 * that in the _previous_ block (which is the current block). */
3262 emit_condition(ctx
, &nif
->condition
, true);
3264 /* Speculatively emit the branch, but we can't fill it in until later */
3265 EMIT(branch
, true, true);
3266 midgard_instruction
*then_branch
= mir_last_in_block(ctx
->current_block
);
3268 /* Emit the two subblocks */
3269 midgard_block
*then_block
= emit_cf_list(ctx
, &nif
->then_list
);
3271 /* Emit a jump from the end of the then block to the end of the else */
3272 EMIT(branch
, false, false);
3273 midgard_instruction
*then_exit
= mir_last_in_block(ctx
->current_block
);
3275 /* Emit second block, and check if it's empty */
3277 int else_idx
= ctx
->block_count
;
3278 int count_in
= ctx
->instruction_count
;
3279 midgard_block
*else_block
= emit_cf_list(ctx
, &nif
->else_list
);
3280 int after_else_idx
= ctx
->block_count
;
3282 /* Now that we have the subblocks emitted, fix up the branches */
3287 if (ctx
->instruction_count
== count_in
) {
3288 /* The else block is empty, so don't emit an exit jump */
3289 mir_remove_instruction(then_exit
);
3290 then_branch
->branch
.target_block
= after_else_idx
;
3292 then_branch
->branch
.target_block
= else_idx
;
3293 then_exit
->branch
.target_block
= after_else_idx
;
3298 emit_loop(struct compiler_context
*ctx
, nir_loop
*nloop
)
3300 /* Remember where we are */
3301 midgard_block
*start_block
= ctx
->current_block
;
3303 /* Allocate a loop number for this. TODO: Nested loops. Instead of a
3304 * single current_loop variable, maybe we need a stack */
3306 int loop_idx
= ++ctx
->current_loop
;
3308 /* Get index from before the body so we can loop back later */
3309 int start_idx
= ctx
->block_count
;
3311 /* Emit the body itself */
3312 emit_cf_list(ctx
, &nloop
->body
);
3314 /* Branch back to loop back */
3315 struct midgard_instruction br_back
= v_branch(false, false);
3316 br_back
.branch
.target_block
= start_idx
;
3317 emit_mir_instruction(ctx
, br_back
);
3319 /* Find the index of the block about to follow us (note: we don't add
3320 * one; blocks are 0-indexed so we get a fencepost problem) */
3321 int break_block_idx
= ctx
->block_count
;
3323 /* Fix up the break statements we emitted to point to the right place,
3324 * now that we can allocate a block number for them */
3326 list_for_each_entry_from(struct midgard_block
, block
, start_block
, &ctx
->blocks
, link
) {
3327 if (midgard_debug
& MIDGARD_DBG_SHADERS
)
3328 print_mir_block(block
);
3329 mir_foreach_instr_in_block(block
, ins
) {
3330 if (ins
->type
!= TAG_ALU_4
) continue;
3331 if (!ins
->compact_branch
) continue;
3332 if (ins
->prepacked_branch
) continue;
3334 /* We found a branch -- check the type to see if we need to do anything */
3335 if (ins
->branch
.target_type
!= TARGET_BREAK
) continue;
3337 /* It's a break! Check if it's our break */
3338 if (ins
->branch
.target_break
!= loop_idx
) continue;
3340 /* Okay, cool, we're breaking out of this loop.
3341 * Rewrite from a break to a goto */
3343 ins
->branch
.target_type
= TARGET_GOTO
;
3344 ins
->branch
.target_block
= break_block_idx
;
3349 static midgard_block
*
3350 emit_cf_list(struct compiler_context
*ctx
, struct exec_list
*list
)
3352 midgard_block
*start_block
= NULL
;
3354 foreach_list_typed(nir_cf_node
, node
, node
, list
) {
3355 switch (node
->type
) {
3356 case nir_cf_node_block
: {
3357 midgard_block
*block
= emit_block(ctx
, nir_cf_node_as_block(node
));
3360 start_block
= block
;
3365 case nir_cf_node_if
:
3366 emit_if(ctx
, nir_cf_node_as_if(node
));
3369 case nir_cf_node_loop
:
3370 emit_loop(ctx
, nir_cf_node_as_loop(node
));
3373 case nir_cf_node_function
:
3382 /* Due to lookahead, we need to report the first tag executed in the command
3383 * stream and in branch targets. An initial block might be empty, so iterate
3384 * until we find one that 'works' */
3387 midgard_get_first_tag_from_block(compiler_context
*ctx
, unsigned block_idx
)
3389 midgard_block
*initial_block
= mir_get_block(ctx
, block_idx
);
3391 unsigned first_tag
= 0;
3394 midgard_bundle
*initial_bundle
= util_dynarray_element(&initial_block
->bundles
, midgard_bundle
, 0);
3396 if (initial_bundle
) {
3397 first_tag
= initial_bundle
->tag
;
3401 /* Initial block is empty, try the next block */
3402 initial_block
= list_first_entry(&(initial_block
->link
), midgard_block
, link
);
3403 } while(initial_block
!= NULL
);
3410 midgard_compile_shader_nir(nir_shader
*nir
, midgard_program
*program
, bool is_blend
)
3412 struct util_dynarray
*compiled
= &program
->compiled
;
3414 midgard_debug
= debug_get_option_midgard_debug();
3416 compiler_context ictx
= {
3418 .stage
= nir
->info
.stage
,
3420 .is_blend
= is_blend
,
3421 .blend_constant_offset
= -1,
3423 .alpha_ref
= program
->alpha_ref
3426 compiler_context
*ctx
= &ictx
;
3428 /* TODO: Decide this at runtime */
3429 ctx
->uniform_cutoff
= 8;
3431 switch (ctx
->stage
) {
3432 case MESA_SHADER_VERTEX
:
3433 ctx
->special_uniforms
= 1;
3437 ctx
->special_uniforms
= 0;
3441 /* Append epilogue uniforms if necessary. The cmdstream depends on
3442 * these being at the -end-; see assign_var_locations. */
3444 if (ctx
->stage
== MESA_SHADER_VERTEX
) {
3445 nir_variable_create(nir
, nir_var_uniform
, glsl_vec4_type(), "viewport");
3448 /* Assign var locations early, so the epilogue can use them if necessary */
3450 nir_assign_var_locations(&nir
->outputs
, &nir
->num_outputs
, glsl_type_size
);
3451 nir_assign_var_locations(&nir
->inputs
, &nir
->num_inputs
, glsl_type_size
);
3452 nir_assign_var_locations(&nir
->uniforms
, &nir
->num_uniforms
, glsl_type_size
);
3454 /* Initialize at a global (not block) level hash tables */
3456 ctx
->ssa_constants
= _mesa_hash_table_u64_create(NULL
);
3457 ctx
->ssa_varyings
= _mesa_hash_table_u64_create(NULL
);
3458 ctx
->ssa_to_alias
= _mesa_hash_table_u64_create(NULL
);
3459 ctx
->ssa_to_register
= _mesa_hash_table_u64_create(NULL
);
3460 ctx
->hash_to_temp
= _mesa_hash_table_u64_create(NULL
);
3461 ctx
->leftover_ssa_to_alias
= _mesa_set_create(NULL
, _mesa_hash_pointer
, _mesa_key_pointer_equal
);
3463 /* Assign actual uniform location, skipping over samplers */
3465 ctx
->uniform_nir_to_mdg
= _mesa_hash_table_u64_create(NULL
);
3467 nir_foreach_variable(var
, &nir
->uniforms
) {
3468 if (glsl_get_base_type(var
->type
) == GLSL_TYPE_SAMPLER
) continue;
3470 unsigned length
= glsl_get_aoa_size(var
->type
);
3473 length
= glsl_get_length(var
->type
);
3477 length
= glsl_get_matrix_columns(var
->type
);
3480 for (int col
= 0; col
< length
; ++col
) {
3481 int id
= ctx
->uniform_count
++;
3482 _mesa_hash_table_u64_insert(ctx
->uniform_nir_to_mdg
, var
->data
.driver_location
+ col
+ 1, (void *) ((uintptr_t) (id
+ 1)));
3486 /* Record the varying mapping for the command stream's bookkeeping */
3488 struct exec_list
*varyings
=
3489 ctx
->stage
== MESA_SHADER_VERTEX
? &nir
->outputs
: &nir
->inputs
;
3491 nir_foreach_variable(var
, varyings
) {
3492 unsigned loc
= var
->data
.driver_location
;
3493 program
->varyings
[loc
] = var
->data
.location
;
3496 /* Lower vars -- not I/O -- before epilogue */
3498 NIR_PASS_V(nir
, nir_lower_var_copies
);
3499 NIR_PASS_V(nir
, nir_lower_vars_to_ssa
);
3500 NIR_PASS_V(nir
, nir_split_var_copies
);
3501 NIR_PASS_V(nir
, nir_lower_var_copies
);
3502 NIR_PASS_V(nir
, nir_lower_global_vars_to_local
);
3503 NIR_PASS_V(nir
, nir_lower_var_copies
);
3504 NIR_PASS_V(nir
, nir_lower_vars_to_ssa
);
3505 NIR_PASS_V(nir
, nir_lower_io
, nir_var_all
, glsl_type_size
, 0);
3507 /* Append vertex epilogue before optimisation, so the epilogue itself
3510 if (ctx
->stage
== MESA_SHADER_VERTEX
)
3511 transform_position_writes(nir
);
3513 /* Optimisation passes */
3517 if (midgard_debug
& MIDGARD_DBG_SHADERS
) {
3518 nir_print_shader(nir
, stdout
);
3521 /* Assign counts, now that we're sure (post-optimisation) */
3522 program
->uniform_count
= nir
->num_uniforms
;
3524 program
->attribute_count
= (ctx
->stage
== MESA_SHADER_VERTEX
) ? nir
->num_inputs
: 0;
3525 program
->varying_count
= (ctx
->stage
== MESA_SHADER_VERTEX
) ? nir
->num_outputs
: ((ctx
->stage
== MESA_SHADER_FRAGMENT
) ? nir
->num_inputs
: 0);
3528 nir_foreach_function(func
, nir
) {
3532 list_inithead(&ctx
->blocks
);
3533 ctx
->block_count
= 0;
3536 emit_cf_list(ctx
, &func
->impl
->body
);
3537 emit_block(ctx
, func
->impl
->end_block
);
3539 break; /* TODO: Multi-function shaders */
3542 util_dynarray_init(compiled
, NULL
);
3545 schedule_program(ctx
);
3547 /* Now that all the bundles are scheduled and we can calculate block
3548 * sizes, emit actual branch instructions rather than placeholders */
3550 int br_block_idx
= 0;
3552 mir_foreach_block(ctx
, block
) {
3553 util_dynarray_foreach(&block
->bundles
, midgard_bundle
, bundle
) {
3554 for (int c
= 0; c
< bundle
->instruction_count
; ++c
) {
3555 midgard_instruction
*ins
= &bundle
->instructions
[c
];
3557 if (!midgard_is_branch_unit(ins
->unit
)) continue;
3559 if (ins
->prepacked_branch
) continue;
3561 /* Parse some basic branch info */
3562 bool is_compact
= ins
->unit
== ALU_ENAB_BR_COMPACT
;
3563 bool is_conditional
= ins
->branch
.conditional
;
3564 bool is_inverted
= ins
->branch
.invert_conditional
;
3565 bool is_discard
= ins
->branch
.target_type
== TARGET_DISCARD
;
3567 /* Determine the block we're jumping to */
3568 int target_number
= ins
->branch
.target_block
;
3570 /* Report the destination tag. Discards don't need this */
3571 int dest_tag
= is_discard
? 0 : midgard_get_first_tag_from_block(ctx
, target_number
);
3573 /* Count up the number of quadwords we're jumping over. That is, the number of quadwords in each of the blocks between (br_block_idx, target_number) */
3574 int quadword_offset
= 0;
3577 /* Jump to the end of the shader. We
3578 * need to include not only the
3579 * following blocks, but also the
3580 * contents of our current block (since
3581 * discard can come in the middle of
3584 midgard_block
*blk
= mir_get_block(ctx
, br_block_idx
+ 1);
3586 for (midgard_bundle
*bun
= bundle
+ 1; bun
< (midgard_bundle
*)((char*) block
->bundles
.data
+ block
->bundles
.size
); ++bun
) {
3587 quadword_offset
+= quadword_size(bun
->tag
);
3590 mir_foreach_block_from(ctx
, blk
, b
) {
3591 quadword_offset
+= b
->quadword_count
;
3594 } else if (target_number
> br_block_idx
) {
3597 for (int idx
= br_block_idx
+ 1; idx
< target_number
; ++idx
) {
3598 midgard_block
*blk
= mir_get_block(ctx
, idx
);
3601 quadword_offset
+= blk
->quadword_count
;
3604 /* Jump backwards */
3606 for (int idx
= br_block_idx
; idx
>= target_number
; --idx
) {
3607 midgard_block
*blk
= mir_get_block(ctx
, idx
);
3610 quadword_offset
-= blk
->quadword_count
;
3614 /* Unconditional extended branches (far jumps)
3615 * have issues, so we always use a conditional
3616 * branch, setting the condition to always for
3617 * unconditional. For compact unconditional
3618 * branches, cond isn't used so it doesn't
3619 * matter what we pick. */
3621 midgard_condition cond
=
3622 !is_conditional
? midgard_condition_always
:
3623 is_inverted
? midgard_condition_false
:
3624 midgard_condition_true
;
3626 midgard_jmp_writeout_op op
=
3627 is_discard
? midgard_jmp_writeout_op_discard
:
3628 (is_compact
&& !is_conditional
) ? midgard_jmp_writeout_op_branch_uncond
:
3629 midgard_jmp_writeout_op_branch_cond
;
3632 midgard_branch_extended branch
=
3633 midgard_create_branch_extended(
3638 memcpy(&ins
->branch_extended
, &branch
, sizeof(branch
));
3639 } else if (is_conditional
|| is_discard
) {
3640 midgard_branch_cond branch
= {
3642 .dest_tag
= dest_tag
,
3643 .offset
= quadword_offset
,
3647 assert(branch
.offset
== quadword_offset
);
3649 memcpy(&ins
->br_compact
, &branch
, sizeof(branch
));
3651 assert(op
== midgard_jmp_writeout_op_branch_uncond
);
3653 midgard_branch_uncond branch
= {
3655 .dest_tag
= dest_tag
,
3656 .offset
= quadword_offset
,
3660 assert(branch
.offset
== quadword_offset
);
3662 memcpy(&ins
->br_compact
, &branch
, sizeof(branch
));
3670 /* Emit flat binary from the instruction arrays. Iterate each block in
3671 * sequence. Save instruction boundaries such that lookahead tags can
3672 * be assigned easily */
3674 /* Cache _all_ bundles in source order for lookahead across failed branches */
3676 int bundle_count
= 0;
3677 mir_foreach_block(ctx
, block
) {
3678 bundle_count
+= block
->bundles
.size
/ sizeof(midgard_bundle
);
3680 midgard_bundle
**source_order_bundles
= malloc(sizeof(midgard_bundle
*) * bundle_count
);
3682 mir_foreach_block(ctx
, block
) {
3683 util_dynarray_foreach(&block
->bundles
, midgard_bundle
, bundle
) {
3684 source_order_bundles
[bundle_idx
++] = bundle
;
3688 int current_bundle
= 0;
3690 mir_foreach_block(ctx
, block
) {
3691 util_dynarray_foreach(&block
->bundles
, midgard_bundle
, bundle
) {
3694 if (current_bundle
+ 1 < bundle_count
) {
3695 uint8_t next
= source_order_bundles
[current_bundle
+ 1]->tag
;
3697 if (!(current_bundle
+ 2 < bundle_count
) && IS_ALU(next
)) {
3704 emit_binary_bundle(ctx
, bundle
, compiled
, lookahead
);
3708 /* TODO: Free deeper */
3709 //util_dynarray_fini(&block->instructions);
3712 free(source_order_bundles
);
3714 /* Report the very first tag executed */
3715 program
->first_tag
= midgard_get_first_tag_from_block(ctx
, 0);
3717 /* Deal with off-by-one related to the fencepost problem */
3718 program
->work_register_count
= ctx
->work_registers
+ 1;
3720 program
->can_discard
= ctx
->can_discard
;
3721 program
->uniform_cutoff
= ctx
->uniform_cutoff
;
3723 program
->blend_patch_offset
= ctx
->blend_constant_offset
;
3725 if (midgard_debug
& MIDGARD_DBG_SHADERS
)
3726 disassemble_midgard(program
->compiled
.data
, program
->compiled
.size
);