2 * Copyright (C) 2018-2019 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/u_debug.h"
40 #include "util/u_dynarray.h"
41 #include "util/list.h"
42 #include "main/mtypes.h"
45 #include "midgard_nir.h"
46 #include "midgard_compile.h"
47 #include "midgard_ops.h"
51 #include "disassemble.h"
53 static const struct debug_named_value debug_options
[] = {
54 {"msgs", MIDGARD_DBG_MSGS
, "Print debug messages"},
55 {"shaders", MIDGARD_DBG_SHADERS
, "Dump shaders in NIR and MIR"},
59 DEBUG_GET_ONCE_FLAGS_OPTION(midgard_debug
, "MIDGARD_MESA_DEBUG", debug_options
, 0)
61 int midgard_debug
= 0;
63 #define DBG(fmt, ...) \
64 do { if (midgard_debug & MIDGARD_DBG_MSGS) \
65 fprintf(stderr, "%s:%d: "fmt, \
66 __FUNCTION__, __LINE__, ##__VA_ARGS__); } while (0)
69 midgard_is_branch_unit(unsigned unit
)
71 return (unit
== ALU_ENAB_BRANCH
) || (unit
== ALU_ENAB_BR_COMPACT
);
75 midgard_block_add_successor(midgard_block
*block
, midgard_block
*successor
)
77 block
->successors
[block
->nr_successors
++] = successor
;
78 assert(block
->nr_successors
<= ARRAY_SIZE(block
->successors
));
81 /* Helpers to generate midgard_instruction's using macro magic, since every
82 * driver seems to do it that way */
84 #define EMIT(op, ...) emit_mir_instruction(ctx, v_##op(__VA_ARGS__));
85 #define SWIZZLE_XYZW SWIZZLE(COMPONENT_X, COMPONENT_Y, COMPONENT_Z, COMPONENT_W)
86 #define SWIZZLE_XXXX SWIZZLE(COMPONENT_X, COMPONENT_X, COMPONENT_X, COMPONENT_X)
87 #define SWIZZLE_WWWW SWIZZLE(COMPONENT_W, COMPONENT_W, COMPONENT_W, COMPONENT_W)
89 #define M_LOAD_STORE(name, rname, uname) \
90 static midgard_instruction m_##name(unsigned ssa, unsigned address) { \
91 midgard_instruction i = { \
92 .type = TAG_LOAD_STORE_4, \
99 .op = midgard_op_##name, \
101 .swizzle = SWIZZLE_XYZW, \
109 #define M_LOAD(name) M_LOAD_STORE(name, dest, src0)
110 #define M_STORE(name) M_LOAD_STORE(name, src0, dest)
112 /* Inputs a NIR ALU source, with modifiers attached if necessary, and outputs
113 * the corresponding Midgard source */
115 static midgard_vector_alu_src
116 vector_alu_modifiers(nir_alu_src
*src
, bool is_int
)
118 if (!src
) return blank_alu_src
;
120 midgard_vector_alu_src alu_src
= {
123 .half
= 0, /* TODO */
124 .swizzle
= SWIZZLE_FROM_ARRAY(src
->swizzle
)
128 /* TODO: sign-extend/zero-extend */
129 alu_src
.mod
= midgard_int_normal
;
131 /* These should have been lowered away */
132 assert(!(src
->abs
|| src
->negate
));
134 alu_src
.mod
= (src
->abs
<< 0) | (src
->negate
<< 1);
140 /* load/store instructions have both 32-bit and 16-bit variants, depending on
141 * whether we are using vectors composed of highp or mediump. At the moment, we
142 * don't support half-floats -- this requires changes in other parts of the
143 * compiler -- therefore the 16-bit versions are commented out. */
145 //M_LOAD(ld_attr_16);
147 //M_LOAD(ld_vary_16);
149 //M_LOAD(ld_uniform_16);
150 M_LOAD(ld_uniform_32
);
151 M_LOAD(ld_color_buffer_8
);
152 //M_STORE(st_vary_16);
154 M_STORE(st_cubemap_coords
);
156 static midgard_instruction
157 v_alu_br_compact_cond(midgard_jmp_writeout_op op
, unsigned tag
, signed offset
, unsigned cond
)
159 midgard_branch_cond branch
= {
167 memcpy(&compact
, &branch
, sizeof(branch
));
169 midgard_instruction ins
= {
171 .unit
= ALU_ENAB_BR_COMPACT
,
172 .prepacked_branch
= true,
173 .compact_branch
= true,
174 .br_compact
= compact
177 if (op
== midgard_jmp_writeout_op_writeout
)
183 static midgard_instruction
184 v_branch(bool conditional
, bool invert
)
186 midgard_instruction ins
= {
188 .unit
= ALU_ENAB_BRANCH
,
189 .compact_branch
= true,
191 .conditional
= conditional
,
192 .invert_conditional
= invert
199 static midgard_branch_extended
200 midgard_create_branch_extended( midgard_condition cond
,
201 midgard_jmp_writeout_op op
,
203 signed quadword_offset
)
205 /* For unclear reasons, the condition code is repeated 8 times */
206 uint16_t duplicated_cond
=
216 midgard_branch_extended branch
= {
218 .dest_tag
= dest_tag
,
219 .offset
= quadword_offset
,
220 .cond
= duplicated_cond
227 attach_constants(compiler_context
*ctx
, midgard_instruction
*ins
, void *constants
, int name
)
229 ins
->has_constants
= true;
230 memcpy(&ins
->constants
, constants
, 16);
234 glsl_type_size(const struct glsl_type
*type
, bool bindless
)
236 return glsl_count_attribute_slots(type
, false);
239 /* Lower fdot2 to a vector multiplication followed by channel addition */
241 midgard_nir_lower_fdot2_body(nir_builder
*b
, nir_alu_instr
*alu
)
243 if (alu
->op
!= nir_op_fdot2
)
246 b
->cursor
= nir_before_instr(&alu
->instr
);
248 nir_ssa_def
*src0
= nir_ssa_for_alu_src(b
, alu
, 0);
249 nir_ssa_def
*src1
= nir_ssa_for_alu_src(b
, alu
, 1);
251 nir_ssa_def
*product
= nir_fmul(b
, src0
, src1
);
253 nir_ssa_def
*sum
= nir_fadd(b
,
254 nir_channel(b
, product
, 0),
255 nir_channel(b
, product
, 1));
257 /* Replace the fdot2 with this sum */
258 nir_ssa_def_rewrite_uses(&alu
->dest
.dest
.ssa
, nir_src_for_ssa(sum
));
262 midgard_nir_sysval_for_intrinsic(nir_intrinsic_instr
*instr
)
264 switch (instr
->intrinsic
) {
265 case nir_intrinsic_load_viewport_scale
:
266 return PAN_SYSVAL_VIEWPORT_SCALE
;
267 case nir_intrinsic_load_viewport_offset
:
268 return PAN_SYSVAL_VIEWPORT_OFFSET
;
275 midgard_nir_assign_sysval_body(compiler_context
*ctx
, nir_instr
*instr
)
279 if (instr
->type
== nir_instr_type_intrinsic
) {
280 nir_intrinsic_instr
*intr
= nir_instr_as_intrinsic(instr
);
281 sysval
= midgard_nir_sysval_for_intrinsic(intr
);
287 /* We have a sysval load; check if it's already been assigned */
289 if (_mesa_hash_table_u64_search(ctx
->sysval_to_id
, sysval
))
292 /* It hasn't -- so assign it now! */
294 unsigned id
= ctx
->sysval_count
++;
295 _mesa_hash_table_u64_insert(ctx
->sysval_to_id
, sysval
, (void *) ((uintptr_t) id
+ 1));
296 ctx
->sysvals
[id
] = sysval
;
300 midgard_nir_assign_sysvals(compiler_context
*ctx
, nir_shader
*shader
)
302 ctx
->sysval_count
= 0;
304 nir_foreach_function(function
, shader
) {
305 if (!function
->impl
) continue;
307 nir_foreach_block(block
, function
->impl
) {
308 nir_foreach_instr_safe(instr
, block
) {
309 midgard_nir_assign_sysval_body(ctx
, instr
);
316 midgard_nir_lower_fdot2(nir_shader
*shader
)
318 bool progress
= false;
320 nir_foreach_function(function
, shader
) {
321 if (!function
->impl
) continue;
324 nir_builder
*b
= &_b
;
325 nir_builder_init(b
, function
->impl
);
327 nir_foreach_block(block
, function
->impl
) {
328 nir_foreach_instr_safe(instr
, block
) {
329 if (instr
->type
!= nir_instr_type_alu
) continue;
331 nir_alu_instr
*alu
= nir_instr_as_alu(instr
);
332 midgard_nir_lower_fdot2_body(b
, alu
);
338 nir_metadata_preserve(function
->impl
, nir_metadata_block_index
| nir_metadata_dominance
);
346 optimise_nir(nir_shader
*nir
)
349 unsigned lower_flrp
=
350 (nir
->options
->lower_flrp16
? 16 : 0) |
351 (nir
->options
->lower_flrp32
? 32 : 0) |
352 (nir
->options
->lower_flrp64
? 64 : 0);
354 NIR_PASS(progress
, nir
, nir_lower_regs_to_ssa
);
355 NIR_PASS(progress
, nir
, midgard_nir_lower_fdot2
);
356 NIR_PASS(progress
, nir
, nir_lower_idiv
);
358 nir_lower_tex_options lower_tex_options
= {
362 NIR_PASS(progress
, nir
, nir_lower_tex
, &lower_tex_options
);
367 NIR_PASS(progress
, nir
, nir_lower_var_copies
);
368 NIR_PASS(progress
, nir
, nir_lower_vars_to_ssa
);
370 NIR_PASS(progress
, nir
, nir_copy_prop
);
371 NIR_PASS(progress
, nir
, nir_opt_dce
);
372 NIR_PASS(progress
, nir
, nir_opt_dead_cf
);
373 NIR_PASS(progress
, nir
, nir_opt_cse
);
374 NIR_PASS(progress
, nir
, nir_opt_peephole_select
, 64, false, true);
375 NIR_PASS(progress
, nir
, nir_opt_algebraic
);
376 NIR_PASS(progress
, nir
, nir_opt_constant_folding
);
378 if (lower_flrp
!= 0) {
379 bool lower_flrp_progress
= false;
380 NIR_PASS(lower_flrp_progress
,
384 false /* always_precise */,
385 nir
->options
->lower_ffma
);
386 if (lower_flrp_progress
) {
387 NIR_PASS(progress
, nir
,
388 nir_opt_constant_folding
);
392 /* Nothing should rematerialize any flrps, so we only
393 * need to do this lowering once.
398 NIR_PASS(progress
, nir
, nir_opt_undef
);
399 NIR_PASS(progress
, nir
, nir_opt_loop_unroll
,
402 nir_var_function_temp
);
404 /* TODO: Enable vectorize when merged upstream */
405 // NIR_PASS(progress, nir, nir_opt_vectorize);
408 /* Must be run at the end to prevent creation of fsin/fcos ops */
409 NIR_PASS(progress
, nir
, midgard_nir_scale_trig
);
414 NIR_PASS(progress
, nir
, nir_opt_dce
);
415 NIR_PASS(progress
, nir
, nir_opt_algebraic
);
416 NIR_PASS(progress
, nir
, nir_opt_constant_folding
);
417 NIR_PASS(progress
, nir
, nir_copy_prop
);
420 NIR_PASS(progress
, nir
, nir_opt_algebraic_late
);
422 /* We implement booleans as 32-bit 0/~0 */
423 NIR_PASS(progress
, nir
, nir_lower_bool_to_int32
);
425 /* Now that booleans are lowered, we can run out late opts */
426 NIR_PASS(progress
, nir
, midgard_nir_lower_algebraic_late
);
428 /* Lower mods for float ops only. Integer ops don't support modifiers
429 * (saturate doesn't make sense on integers, neg/abs require dedicated
432 NIR_PASS(progress
, nir
, nir_lower_to_source_mods
, nir_lower_float_source_mods
);
433 NIR_PASS(progress
, nir
, nir_copy_prop
);
434 NIR_PASS(progress
, nir
, nir_opt_dce
);
436 /* Take us out of SSA */
437 NIR_PASS(progress
, nir
, nir_lower_locals_to_regs
);
438 NIR_PASS(progress
, nir
, nir_convert_from_ssa
, true);
440 /* We are a vector architecture; write combine where possible */
441 NIR_PASS(progress
, nir
, nir_move_vec_src_uses_to_dest
);
442 NIR_PASS(progress
, nir
, nir_lower_vec_to_movs
);
444 NIR_PASS(progress
, nir
, nir_opt_dce
);
447 /* Front-half of aliasing the SSA slots, merely by inserting the flag in the
448 * appropriate hash table. Intentional off-by-one to avoid confusing NULL with
449 * r0. See the comments in compiler_context */
452 alias_ssa(compiler_context
*ctx
, int dest
, int src
)
454 _mesa_hash_table_u64_insert(ctx
->ssa_to_alias
, dest
+ 1, (void *) ((uintptr_t) src
+ 1));
455 _mesa_set_add(ctx
->leftover_ssa_to_alias
, (void *) (uintptr_t) (dest
+ 1));
458 /* ...or undo it, after which the original index will be used (dummy move should be emitted alongside this) */
461 unalias_ssa(compiler_context
*ctx
, int dest
)
463 _mesa_hash_table_u64_remove(ctx
->ssa_to_alias
, dest
+ 1);
464 /* TODO: Remove from leftover or no? */
467 /* Do not actually emit a load; instead, cache the constant for inlining */
470 emit_load_const(compiler_context
*ctx
, nir_load_const_instr
*instr
)
472 nir_ssa_def def
= instr
->def
;
474 float *v
= rzalloc_array(NULL
, float, 4);
475 nir_const_load_to_arr(v
, instr
, f32
);
476 _mesa_hash_table_u64_insert(ctx
->ssa_constants
, def
.index
+ 1, v
);
480 nir_src_index(compiler_context
*ctx
, nir_src
*src
)
483 return src
->ssa
->index
;
485 assert(!src
->reg
.indirect
);
486 return ctx
->func
->impl
->ssa_alloc
+ src
->reg
.reg
->index
;
491 nir_dest_index(compiler_context
*ctx
, nir_dest
*dst
)
494 return dst
->ssa
.index
;
496 assert(!dst
->reg
.indirect
);
497 return ctx
->func
->impl
->ssa_alloc
+ dst
->reg
.reg
->index
;
502 nir_alu_src_index(compiler_context
*ctx
, nir_alu_src
*src
)
504 return nir_src_index(ctx
, &src
->src
);
508 nir_is_non_scalar_swizzle(nir_alu_src
*src
, unsigned nr_components
)
510 unsigned comp
= src
->swizzle
[0];
512 for (unsigned c
= 1; c
< nr_components
; ++c
) {
513 if (src
->swizzle
[c
] != comp
)
520 /* Midgard puts scalar conditionals in r31.w; move an arbitrary source (the
521 * output of a conditional test) into that register */
524 emit_condition(compiler_context
*ctx
, nir_src
*src
, bool for_branch
, unsigned component
)
526 int condition
= nir_src_index(ctx
, src
);
528 /* Source to swizzle the desired component into w */
530 const midgard_vector_alu_src alu_src
= {
531 .swizzle
= SWIZZLE(component
, component
, component
, component
),
534 /* There is no boolean move instruction. Instead, we simulate a move by
535 * ANDing the condition with itself to get it into r31.w */
537 midgard_instruction ins
= {
540 /* We need to set the conditional as close as possible */
541 .precede_break
= true,
542 .unit
= for_branch
? UNIT_SMUL
: UNIT_SADD
,
547 .dest
= SSA_FIXED_REGISTER(31),
551 .op
= midgard_alu_op_iand
,
552 .outmod
= midgard_outmod_int_wrap
,
553 .reg_mode
= midgard_reg_mode_32
,
554 .dest_override
= midgard_dest_override_none
,
555 .mask
= (0x3 << 6), /* w */
556 .src1
= vector_alu_srco_unsigned(alu_src
),
557 .src2
= vector_alu_srco_unsigned(alu_src
)
561 emit_mir_instruction(ctx
, ins
);
564 /* Or, for mixed conditions (with csel_v), here's a vector version using all of
568 emit_condition_mixed(compiler_context
*ctx
, nir_alu_src
*src
, unsigned nr_comp
)
570 int condition
= nir_src_index(ctx
, &src
->src
);
572 /* Source to swizzle the desired component into w */
574 const midgard_vector_alu_src alu_src
= {
575 .swizzle
= SWIZZLE_FROM_ARRAY(src
->swizzle
),
578 /* There is no boolean move instruction. Instead, we simulate a move by
579 * ANDing the condition with itself to get it into r31.w */
581 midgard_instruction ins
= {
583 .precede_break
= true,
587 .dest
= SSA_FIXED_REGISTER(31),
590 .op
= midgard_alu_op_iand
,
591 .outmod
= midgard_outmod_int_wrap
,
592 .reg_mode
= midgard_reg_mode_32
,
593 .dest_override
= midgard_dest_override_none
,
594 .mask
= expand_writemask((1 << nr_comp
) - 1),
595 .src1
= vector_alu_srco_unsigned(alu_src
),
596 .src2
= vector_alu_srco_unsigned(alu_src
)
600 emit_mir_instruction(ctx
, ins
);
605 /* Likewise, indirect offsets are put in r27.w. TODO: Allow componentwise
606 * pinning to eliminate this move in all known cases */
609 emit_indirect_offset(compiler_context
*ctx
, nir_src
*src
)
611 int offset
= nir_src_index(ctx
, src
);
613 midgard_instruction ins
= {
616 .src0
= SSA_UNUSED_1
,
618 .dest
= SSA_FIXED_REGISTER(REGISTER_OFFSET
),
621 .op
= midgard_alu_op_imov
,
622 .outmod
= midgard_outmod_int_wrap
,
623 .reg_mode
= midgard_reg_mode_32
,
624 .dest_override
= midgard_dest_override_none
,
625 .mask
= (0x3 << 6), /* w */
626 .src1
= vector_alu_srco_unsigned(zero_alu_src
),
627 .src2
= vector_alu_srco_unsigned(blank_alu_src_xxxx
)
631 emit_mir_instruction(ctx
, ins
);
634 #define ALU_CASE(nir, _op) \
636 op = midgard_alu_op_##_op; \
639 nir_is_fzero_constant(nir_src src
)
641 if (!nir_src_is_const(src
))
644 for (unsigned c
= 0; c
< nir_src_num_components(src
); ++c
) {
645 if (nir_src_comp_as_float(src
, c
) != 0.0)
653 emit_alu(compiler_context
*ctx
, nir_alu_instr
*instr
)
655 bool is_ssa
= instr
->dest
.dest
.is_ssa
;
657 unsigned dest
= nir_dest_index(ctx
, &instr
->dest
.dest
);
658 unsigned nr_components
= is_ssa
? instr
->dest
.dest
.ssa
.num_components
: instr
->dest
.dest
.reg
.reg
->num_components
;
659 unsigned nr_inputs
= nir_op_infos
[instr
->op
].num_inputs
;
661 /* Most Midgard ALU ops have a 1:1 correspondance to NIR ops; these are
662 * supported. A few do not and are commented for now. Also, there are a
663 * number of NIR ops which Midgard does not support and need to be
664 * lowered, also TODO. This switch block emits the opcode and calling
665 * convention of the Midgard instruction; actual packing is done in
671 ALU_CASE(fadd
, fadd
);
672 ALU_CASE(fmul
, fmul
);
673 ALU_CASE(fmin
, fmin
);
674 ALU_CASE(fmax
, fmax
);
675 ALU_CASE(imin
, imin
);
676 ALU_CASE(imax
, imax
);
677 ALU_CASE(umin
, umin
);
678 ALU_CASE(umax
, umax
);
679 ALU_CASE(ffloor
, ffloor
);
680 ALU_CASE(fround_even
, froundeven
);
681 ALU_CASE(ftrunc
, ftrunc
);
682 ALU_CASE(fceil
, fceil
);
683 ALU_CASE(fdot3
, fdot3
);
684 ALU_CASE(fdot4
, fdot4
);
685 ALU_CASE(iadd
, iadd
);
686 ALU_CASE(isub
, isub
);
687 ALU_CASE(imul
, imul
);
689 /* Zero shoved as second-arg */
690 ALU_CASE(iabs
, iabsdiff
);
694 ALU_CASE(feq32
, feq
);
695 ALU_CASE(fne32
, fne
);
696 ALU_CASE(flt32
, flt
);
697 ALU_CASE(ieq32
, ieq
);
698 ALU_CASE(ine32
, ine
);
699 ALU_CASE(ilt32
, ilt
);
700 ALU_CASE(ult32
, ult
);
702 /* We don't have a native b2f32 instruction. Instead, like many
703 * GPUs, we exploit booleans as 0/~0 for false/true, and
704 * correspondingly AND
705 * by 1.0 to do the type conversion. For the moment, prime us
708 * iand [whatever], #0
710 * At the end of emit_alu (as MIR), we'll fix-up the constant
713 ALU_CASE(b2f32
, iand
);
714 ALU_CASE(b2i32
, iand
);
716 /* Likewise, we don't have a dedicated f2b32 instruction, but
717 * we can do a "not equal to 0.0" test. */
719 ALU_CASE(f2b32
, fne
);
720 ALU_CASE(i2b32
, ine
);
722 ALU_CASE(frcp
, frcp
);
723 ALU_CASE(frsq
, frsqrt
);
724 ALU_CASE(fsqrt
, fsqrt
);
725 ALU_CASE(fexp2
, fexp2
);
726 ALU_CASE(flog2
, flog2
);
728 ALU_CASE(f2i32
, f2i
);
729 ALU_CASE(f2u32
, f2u
);
730 ALU_CASE(i2f32
, i2f
);
731 ALU_CASE(u2f32
, u2f
);
733 ALU_CASE(fsin
, fsin
);
734 ALU_CASE(fcos
, fcos
);
736 /* Second op implicit #0 */
737 ALU_CASE(inot
, inor
);
738 ALU_CASE(iand
, iand
);
740 ALU_CASE(ixor
, ixor
);
741 ALU_CASE(ishl
, ishl
);
742 ALU_CASE(ishr
, iasr
);
743 ALU_CASE(ushr
, ilsr
);
745 ALU_CASE(b32all_fequal2
, fball_eq
);
746 ALU_CASE(b32all_fequal3
, fball_eq
);
747 ALU_CASE(b32all_fequal4
, fball_eq
);
749 ALU_CASE(b32any_fnequal2
, fbany_neq
);
750 ALU_CASE(b32any_fnequal3
, fbany_neq
);
751 ALU_CASE(b32any_fnequal4
, fbany_neq
);
753 ALU_CASE(b32all_iequal2
, iball_eq
);
754 ALU_CASE(b32all_iequal3
, iball_eq
);
755 ALU_CASE(b32all_iequal4
, iball_eq
);
757 ALU_CASE(b32any_inequal2
, ibany_neq
);
758 ALU_CASE(b32any_inequal3
, ibany_neq
);
759 ALU_CASE(b32any_inequal4
, ibany_neq
);
761 /* Source mods will be shoved in later */
762 ALU_CASE(fabs
, fmov
);
763 ALU_CASE(fneg
, fmov
);
764 ALU_CASE(fsat
, fmov
);
766 /* For greater-or-equal, we lower to less-or-equal and flip the
774 instr
->op
== nir_op_fge
? midgard_alu_op_fle
:
775 instr
->op
== nir_op_fge32
? midgard_alu_op_fle
:
776 instr
->op
== nir_op_ige32
? midgard_alu_op_ile
:
777 instr
->op
== nir_op_uge32
? midgard_alu_op_ule
:
780 /* Swap via temporary */
781 nir_alu_src temp
= instr
->src
[1];
782 instr
->src
[1] = instr
->src
[0];
783 instr
->src
[0] = temp
;
788 case nir_op_b32csel
: {
789 /* Midgard features both fcsel and icsel, depending on
790 * the type of the arguments/output. However, as long
791 * as we're careful we can _always_ use icsel and
792 * _never_ need fcsel, since the latter does additional
793 * floating-point-specific processing whereas the
794 * former just moves bits on the wire. It's not obvious
795 * why these are separate opcodes, save for the ability
796 * to do things like sat/pos/abs/neg for free */
798 bool mixed
= nir_is_non_scalar_swizzle(&instr
->src
[0], nr_components
);
799 op
= mixed
? midgard_alu_op_icsel_v
: midgard_alu_op_icsel
;
801 /* csel works as a two-arg in Midgard, since the condition is hardcoded in r31.w */
804 /* Emit the condition into r31 */
807 emit_condition_mixed(ctx
, &instr
->src
[0], nr_components
);
809 emit_condition(ctx
, &instr
->src
[0].src
, false, instr
->src
[0].swizzle
[0]);
811 /* The condition is the first argument; move the other
812 * arguments up one to be a binary instruction for
815 memmove(instr
->src
, instr
->src
+ 1, 2 * sizeof(nir_alu_src
));
820 DBG("Unhandled ALU op %s\n", nir_op_infos
[instr
->op
].name
);
825 /* Midgard can perform certain modifiers on output of an ALU op */
828 if (midgard_is_integer_out_op(op
)) {
829 outmod
= midgard_outmod_int_wrap
;
831 bool sat
= instr
->dest
.saturate
|| instr
->op
== nir_op_fsat
;
832 outmod
= sat
? midgard_outmod_sat
: midgard_outmod_none
;
835 /* fmax(a, 0.0) can turn into a .pos modifier as an optimization */
837 if (instr
->op
== nir_op_fmax
) {
838 if (nir_is_fzero_constant(instr
->src
[0].src
)) {
839 op
= midgard_alu_op_fmov
;
841 outmod
= midgard_outmod_pos
;
842 instr
->src
[0] = instr
->src
[1];
843 } else if (nir_is_fzero_constant(instr
->src
[1].src
)) {
844 op
= midgard_alu_op_fmov
;
846 outmod
= midgard_outmod_pos
;
850 /* Fetch unit, quirks, etc information */
851 unsigned opcode_props
= alu_opcode_props
[op
].props
;
852 bool quirk_flipped_r24
= opcode_props
& QUIRK_FLIPPED_R24
;
854 /* src0 will always exist afaik, but src1 will not for 1-argument
855 * instructions. The latter can only be fetched if the instruction
856 * needs it, or else we may segfault. */
858 unsigned src0
= nir_alu_src_index(ctx
, &instr
->src
[0]);
859 unsigned src1
= nr_inputs
== 2 ? nir_alu_src_index(ctx
, &instr
->src
[1]) : SSA_UNUSED_0
;
861 /* Rather than use the instruction generation helpers, we do it
862 * ourselves here to avoid the mess */
864 midgard_instruction ins
= {
867 .src0
= quirk_flipped_r24
? SSA_UNUSED_1
: src0
,
868 .src1
= quirk_flipped_r24
? src0
: src1
,
873 nir_alu_src
*nirmods
[2] = { NULL
};
875 if (nr_inputs
== 2) {
876 nirmods
[0] = &instr
->src
[0];
877 nirmods
[1] = &instr
->src
[1];
878 } else if (nr_inputs
== 1) {
879 nirmods
[quirk_flipped_r24
] = &instr
->src
[0];
884 /* These were lowered to a move, so apply the corresponding mod */
886 if (instr
->op
== nir_op_fneg
|| instr
->op
== nir_op_fabs
) {
887 nir_alu_src
*s
= nirmods
[quirk_flipped_r24
];
889 if (instr
->op
== nir_op_fneg
)
890 s
->negate
= !s
->negate
;
892 if (instr
->op
== nir_op_fabs
)
896 bool is_int
= midgard_is_integer_op(op
);
898 midgard_vector_alu alu
= {
900 .reg_mode
= midgard_reg_mode_32
,
901 .dest_override
= midgard_dest_override_none
,
904 /* Writemask only valid for non-SSA NIR */
905 .mask
= expand_writemask((1 << nr_components
) - 1),
907 .src1
= vector_alu_srco_unsigned(vector_alu_modifiers(nirmods
[0], is_int
)),
908 .src2
= vector_alu_srco_unsigned(vector_alu_modifiers(nirmods
[1], is_int
)),
911 /* Apply writemask if non-SSA, keeping in mind that we can't write to components that don't exist */
914 alu
.mask
&= expand_writemask(instr
->dest
.write_mask
);
918 /* Late fixup for emulated instructions */
920 if (instr
->op
== nir_op_b2f32
|| instr
->op
== nir_op_b2i32
) {
921 /* Presently, our second argument is an inline #0 constant.
922 * Switch over to an embedded 1.0 constant (that can't fit
923 * inline, since we're 32-bit, not 16-bit like the inline
926 ins
.ssa_args
.inline_constant
= false;
927 ins
.ssa_args
.src1
= SSA_FIXED_REGISTER(REGISTER_CONSTANT
);
928 ins
.has_constants
= true;
930 if (instr
->op
== nir_op_b2f32
) {
931 ins
.constants
[0] = 1.0f
;
933 /* Type pun it into place */
935 memcpy(&ins
.constants
[0], &one
, sizeof(uint32_t));
938 ins
.alu
.src2
= vector_alu_srco_unsigned(blank_alu_src_xxxx
);
939 } else if (nr_inputs
== 1 && !quirk_flipped_r24
) {
940 /* Lots of instructions need a 0 plonked in */
941 ins
.ssa_args
.inline_constant
= false;
942 ins
.ssa_args
.src1
= SSA_FIXED_REGISTER(REGISTER_CONSTANT
);
943 ins
.has_constants
= true;
944 ins
.constants
[0] = 0.0f
;
945 ins
.alu
.src2
= vector_alu_srco_unsigned(blank_alu_src_xxxx
);
946 } else if (instr
->op
== nir_op_inot
) {
947 /* ~b = ~(b & b), so duplicate the source */
948 ins
.ssa_args
.src1
= ins
.ssa_args
.src0
;
949 ins
.alu
.src2
= ins
.alu
.src1
;
952 if ((opcode_props
& UNITS_ALL
) == UNIT_VLUT
) {
953 /* To avoid duplicating the lookup tables (probably), true LUT
954 * instructions can only operate as if they were scalars. Lower
955 * them here by changing the component. */
957 uint8_t original_swizzle
[4];
958 memcpy(original_swizzle
, nirmods
[0]->swizzle
, sizeof(nirmods
[0]->swizzle
));
960 for (int i
= 0; i
< nr_components
; ++i
) {
961 ins
.alu
.mask
= (0x3) << (2 * i
); /* Mask the associated component */
963 for (int j
= 0; j
< 4; ++j
)
964 nirmods
[0]->swizzle
[j
] = original_swizzle
[i
]; /* Pull from the correct component */
966 ins
.alu
.src1
= vector_alu_srco_unsigned(vector_alu_modifiers(nirmods
[0], is_int
));
967 emit_mir_instruction(ctx
, ins
);
970 emit_mir_instruction(ctx
, ins
);
977 emit_uniform_read(compiler_context
*ctx
, unsigned dest
, unsigned offset
, nir_src
*indirect_offset
)
979 /* TODO: half-floats */
981 if (!indirect_offset
&& offset
< ctx
->uniform_cutoff
) {
982 /* Fast path: For the first 16 uniforms, direct accesses are
983 * 0-cycle, since they're just a register fetch in the usual
984 * case. So, we alias the registers while we're still in
987 int reg_slot
= 23 - offset
;
988 alias_ssa(ctx
, dest
, SSA_FIXED_REGISTER(reg_slot
));
990 /* Otherwise, read from the 'special' UBO to access
991 * higher-indexed uniforms, at a performance cost. More
992 * generally, we're emitting a UBO read instruction. */
994 midgard_instruction ins
= m_ld_uniform_32(dest
, offset
);
996 /* TODO: Don't split */
997 ins
.load_store
.varying_parameters
= (offset
& 7) << 7;
998 ins
.load_store
.address
= offset
>> 3;
1000 if (indirect_offset
) {
1001 emit_indirect_offset(ctx
, indirect_offset
);
1002 ins
.load_store
.unknown
= 0x8700; /* xxx: what is this? */
1004 ins
.load_store
.unknown
= 0x1E00; /* xxx: what is this? */
1007 emit_mir_instruction(ctx
, ins
);
1013 compiler_context
*ctx
,
1014 unsigned dest
, unsigned offset
,
1015 unsigned nr_comp
, unsigned component
,
1016 nir_src
*indirect_offset
)
1018 /* XXX: Half-floats? */
1019 /* TODO: swizzle, mask */
1021 midgard_instruction ins
= m_ld_vary_32(dest
, offset
);
1022 ins
.load_store
.mask
= (1 << nr_comp
) - 1;
1023 ins
.load_store
.swizzle
= SWIZZLE_XYZW
>> (2 * component
);
1025 midgard_varying_parameter p
= {
1027 .interpolation
= midgard_interp_default
,
1028 .flat
= /*var->data.interpolation == INTERP_MODE_FLAT*/ 0
1032 memcpy(&u
, &p
, sizeof(p
));
1033 ins
.load_store
.varying_parameters
= u
;
1035 if (indirect_offset
) {
1036 /* We need to add in the dynamic index, moved to r27.w */
1037 emit_indirect_offset(ctx
, indirect_offset
);
1038 ins
.load_store
.unknown
= 0x79e; /* xxx: what is this? */
1040 /* Just a direct load */
1041 ins
.load_store
.unknown
= 0x1e9e; /* xxx: what is this? */
1044 emit_mir_instruction(ctx
, ins
);
1048 emit_sysval_read(compiler_context
*ctx
, nir_intrinsic_instr
*instr
)
1050 /* First, pull out the destination */
1051 unsigned dest
= nir_dest_index(ctx
, &instr
->dest
);
1053 /* Now, figure out which uniform this is */
1054 int sysval
= midgard_nir_sysval_for_intrinsic(instr
);
1055 void *val
= _mesa_hash_table_u64_search(ctx
->sysval_to_id
, sysval
);
1057 /* Sysvals are prefix uniforms */
1058 unsigned uniform
= ((uintptr_t) val
) - 1;
1060 /* Emit the read itself -- this is never indirect */
1061 emit_uniform_read(ctx
, dest
, uniform
, NULL
);
1064 /* Reads RGBA8888 value from the tilebuffer and converts to a RGBA32F register,
1065 * using scalar ops functional on earlier Midgard generations. Newer Midgard
1066 * generations have faster vectorized reads. This operation is for blend
1067 * shaders in particular; reading the tilebuffer from the fragment shader
1068 * remains an open problem. */
1071 emit_fb_read_blend_scalar(compiler_context
*ctx
, unsigned reg
)
1073 midgard_instruction ins
= m_ld_color_buffer_8(reg
, 0);
1074 ins
.load_store
.swizzle
= 0; /* xxxx */
1076 /* Read each component sequentially */
1078 for (unsigned c
= 0; c
< 4; ++c
) {
1079 ins
.load_store
.mask
= (1 << c
);
1080 ins
.load_store
.unknown
= c
;
1081 emit_mir_instruction(ctx
, ins
);
1084 /* vadd.u2f hr2, zext(hr2), #0 */
1086 midgard_vector_alu_src alu_src
= blank_alu_src
;
1087 alu_src
.mod
= midgard_int_zero_extend
;
1088 alu_src
.half
= true;
1090 midgard_instruction u2f
= {
1094 .src1
= SSA_UNUSED_0
,
1096 .inline_constant
= true
1099 .op
= midgard_alu_op_u2f
,
1100 .reg_mode
= midgard_reg_mode_16
,
1101 .dest_override
= midgard_dest_override_none
,
1103 .src1
= vector_alu_srco_unsigned(alu_src
),
1104 .src2
= vector_alu_srco_unsigned(blank_alu_src
),
1108 emit_mir_instruction(ctx
, u2f
);
1110 /* vmul.fmul.sat r1, hr2, #0.00392151 */
1114 midgard_instruction fmul
= {
1116 .inline_constant
= _mesa_float_to_half(1.0 / 255.0),
1120 .src1
= SSA_UNUSED_0
,
1121 .inline_constant
= true
1124 .op
= midgard_alu_op_fmul
,
1125 .reg_mode
= midgard_reg_mode_32
,
1126 .dest_override
= midgard_dest_override_none
,
1127 .outmod
= midgard_outmod_sat
,
1129 .src1
= vector_alu_srco_unsigned(alu_src
),
1130 .src2
= vector_alu_srco_unsigned(blank_alu_src
),
1134 emit_mir_instruction(ctx
, fmul
);
1138 emit_intrinsic(compiler_context
*ctx
, nir_intrinsic_instr
*instr
)
1140 unsigned offset
, reg
;
1142 switch (instr
->intrinsic
) {
1143 case nir_intrinsic_discard_if
:
1144 emit_condition(ctx
, &instr
->src
[0], true, COMPONENT_X
);
1148 case nir_intrinsic_discard
: {
1149 bool conditional
= instr
->intrinsic
== nir_intrinsic_discard_if
;
1150 struct midgard_instruction discard
= v_branch(conditional
, false);
1151 discard
.branch
.target_type
= TARGET_DISCARD
;
1152 emit_mir_instruction(ctx
, discard
);
1154 ctx
->can_discard
= true;
1158 case nir_intrinsic_load_uniform
:
1159 case nir_intrinsic_load_input
:
1160 offset
= nir_intrinsic_base(instr
);
1162 unsigned nr_comp
= nir_intrinsic_dest_components(instr
);
1163 bool direct
= nir_src_is_const(instr
->src
[0]);
1166 offset
+= nir_src_as_uint(instr
->src
[0]);
1169 /* We may need to apply a fractional offset */
1170 int component
= instr
->intrinsic
== nir_intrinsic_load_input
?
1171 nir_intrinsic_component(instr
) : 0;
1172 reg
= nir_dest_index(ctx
, &instr
->dest
);
1174 if (instr
->intrinsic
== nir_intrinsic_load_uniform
&& !ctx
->is_blend
) {
1175 emit_uniform_read(ctx
, reg
, ctx
->sysval_count
+ offset
, !direct
? &instr
->src
[0] : NULL
);
1176 } else if (ctx
->stage
== MESA_SHADER_FRAGMENT
&& !ctx
->is_blend
) {
1177 emit_varying_read(ctx
, reg
, offset
, nr_comp
, component
, !direct
? &instr
->src
[0] : NULL
);
1178 } else if (ctx
->is_blend
) {
1179 /* For blend shaders, load the input color, which is
1180 * preloaded to r0 */
1182 midgard_instruction move
= v_fmov(reg
, blank_alu_src
, SSA_FIXED_REGISTER(0));
1183 emit_mir_instruction(ctx
, move
);
1184 } else if (ctx
->stage
== MESA_SHADER_VERTEX
) {
1185 midgard_instruction ins
= m_ld_attr_32(reg
, offset
);
1186 ins
.load_store
.unknown
= 0x1E1E; /* XXX: What is this? */
1187 ins
.load_store
.mask
= (1 << nr_comp
) - 1;
1188 emit_mir_instruction(ctx
, ins
);
1190 DBG("Unknown load\n");
1196 case nir_intrinsic_load_output
:
1197 assert(nir_src_is_const(instr
->src
[0]));
1198 reg
= nir_dest_index(ctx
, &instr
->dest
);
1200 if (ctx
->is_blend
) {
1202 emit_fb_read_blend_scalar(ctx
, reg
);
1204 DBG("Unknown output load\n");
1210 case nir_intrinsic_load_blend_const_color_rgba
: {
1211 assert(ctx
->is_blend
);
1212 reg
= nir_dest_index(ctx
, &instr
->dest
);
1214 /* Blend constants are embedded directly in the shader and
1215 * patched in, so we use some magic routing */
1217 midgard_instruction ins
= v_fmov(SSA_FIXED_REGISTER(REGISTER_CONSTANT
), blank_alu_src
, reg
);
1218 ins
.has_constants
= true;
1219 ins
.has_blend_constant
= true;
1220 emit_mir_instruction(ctx
, ins
);
1224 case nir_intrinsic_store_output
:
1225 assert(nir_src_is_const(instr
->src
[1]) && "no indirect outputs");
1227 offset
= nir_intrinsic_base(instr
) + nir_src_as_uint(instr
->src
[1]);
1229 reg
= nir_src_index(ctx
, &instr
->src
[0]);
1231 if (ctx
->stage
== MESA_SHADER_FRAGMENT
) {
1232 /* gl_FragColor is not emitted with load/store
1233 * instructions. Instead, it gets plonked into
1234 * r0 at the end of the shader and we do the
1235 * framebuffer writeout dance. TODO: Defer
1238 midgard_instruction move
= v_fmov(reg
, blank_alu_src
, SSA_FIXED_REGISTER(0));
1239 emit_mir_instruction(ctx
, move
);
1241 /* Save the index we're writing to for later reference
1242 * in the epilogue */
1244 ctx
->fragment_output
= reg
;
1245 } else if (ctx
->stage
== MESA_SHADER_VERTEX
) {
1246 /* Varyings are written into one of two special
1247 * varying register, r26 or r27. The register itself is
1248 * selected as the register in the st_vary instruction,
1249 * minus the base of 26. E.g. write into r27 and then
1250 * call st_vary(1) */
1252 midgard_instruction ins
= v_fmov(reg
, blank_alu_src
, SSA_FIXED_REGISTER(26));
1253 emit_mir_instruction(ctx
, ins
);
1255 /* We should have been vectorized. That also lets us
1256 * ignore the mask. because the mask component on
1257 * st_vary is (as far as I can tell) ignored [the blob
1258 * sets it to zero] */
1259 assert(nir_intrinsic_component(instr
) == 0);
1261 midgard_instruction st
= m_st_vary_32(SSA_FIXED_REGISTER(0), offset
);
1262 st
.load_store
.unknown
= 0x1E9E; /* XXX: What is this? */
1263 emit_mir_instruction(ctx
, st
);
1265 DBG("Unknown store\n");
1271 case nir_intrinsic_load_alpha_ref_float
:
1272 assert(instr
->dest
.is_ssa
);
1274 float ref_value
= ctx
->alpha_ref
;
1276 float *v
= ralloc_array(NULL
, float, 4);
1277 memcpy(v
, &ref_value
, sizeof(float));
1278 _mesa_hash_table_u64_insert(ctx
->ssa_constants
, instr
->dest
.ssa
.index
+ 1, v
);
1281 case nir_intrinsic_load_viewport_scale
:
1282 case nir_intrinsic_load_viewport_offset
:
1283 emit_sysval_read(ctx
, instr
);
1287 printf ("Unhandled intrinsic\n");
1294 midgard_tex_format(enum glsl_sampler_dim dim
)
1297 case GLSL_SAMPLER_DIM_2D
:
1298 case GLSL_SAMPLER_DIM_EXTERNAL
:
1301 case GLSL_SAMPLER_DIM_3D
:
1304 case GLSL_SAMPLER_DIM_CUBE
:
1305 return TEXTURE_CUBE
;
1308 DBG("Unknown sampler dim type\n");
1315 midgard_tex_op(nir_texop op
)
1320 return TEXTURE_OP_NORMAL
;
1322 return TEXTURE_OP_LOD
;
1324 unreachable("Unhanlded texture op");
1329 emit_tex(compiler_context
*ctx
, nir_tex_instr
*instr
)
1332 //assert (!instr->sampler);
1333 //assert (!instr->texture_array_size);
1335 /* Allocate registers via a round robin scheme to alternate between the two registers */
1336 int reg
= ctx
->texture_op_count
& 1;
1337 int in_reg
= reg
, out_reg
= reg
;
1339 /* Make room for the reg */
1341 if (ctx
->texture_index
[reg
] > -1)
1342 unalias_ssa(ctx
, ctx
->texture_index
[reg
]);
1344 int texture_index
= instr
->texture_index
;
1345 int sampler_index
= texture_index
;
1347 for (unsigned i
= 0; i
< instr
->num_srcs
; ++i
) {
1348 int reg
= SSA_FIXED_REGISTER(REGISTER_TEXTURE_BASE
+ in_reg
);
1349 int index
= nir_src_index(ctx
, &instr
->src
[i
].src
);
1350 midgard_vector_alu_src alu_src
= blank_alu_src
;
1352 switch (instr
->src
[i
].src_type
) {
1353 case nir_tex_src_coord
: {
1354 if (instr
->sampler_dim
== GLSL_SAMPLER_DIM_CUBE
) {
1355 /* For cubemaps, we need to load coords into
1356 * special r27, and then use a special ld/st op
1357 * to select the face and copy the xy into the
1358 * texture register */
1360 alu_src
.swizzle
= SWIZZLE(COMPONENT_X
, COMPONENT_Y
, COMPONENT_Z
, COMPONENT_X
);
1362 midgard_instruction move
= v_fmov(index
, alu_src
, SSA_FIXED_REGISTER(27));
1363 emit_mir_instruction(ctx
, move
);
1365 midgard_instruction st
= m_st_cubemap_coords(reg
, 0);
1366 st
.load_store
.unknown
= 0x24; /* XXX: What is this? */
1367 st
.load_store
.mask
= 0x3; /* xy */
1368 st
.load_store
.swizzle
= alu_src
.swizzle
;
1369 emit_mir_instruction(ctx
, st
);
1372 alu_src
.swizzle
= SWIZZLE(COMPONENT_X
, COMPONENT_Y
, COMPONENT_X
, COMPONENT_X
);
1374 midgard_instruction ins
= v_fmov(index
, alu_src
, reg
);
1375 ins
.alu
.mask
= expand_writemask(0x3); /* xy */
1376 emit_mir_instruction(ctx
, ins
);
1382 case nir_tex_src_bias
:
1383 case nir_tex_src_lod
: {
1384 /* To keep RA simple, we put the bias/LOD into the w
1385 * component of the input source, which is otherwise in xy */
1387 alu_src
.swizzle
= SWIZZLE_XXXX
;
1389 midgard_instruction ins
= v_fmov(index
, alu_src
, reg
);
1390 ins
.alu
.mask
= expand_writemask(1 << COMPONENT_W
);
1391 emit_mir_instruction(ctx
, ins
);
1396 DBG("Unknown source type\n");
1403 /* No helper to build texture words -- we do it all here */
1404 midgard_instruction ins
= {
1405 .type
= TAG_TEXTURE_4
,
1407 .op
= midgard_tex_op(instr
->op
),
1408 .format
= midgard_tex_format(instr
->sampler_dim
),
1409 .texture_handle
= texture_index
,
1410 .sampler_handle
= sampler_index
,
1412 /* TODO: Regalloc it in */
1413 .swizzle
= SWIZZLE_XYZW
,
1418 .in_reg_swizzle
= SWIZZLE_XYZW
,
1426 /* Set registers to read and write from the same place */
1427 ins
.texture
.in_reg_select
= in_reg
;
1428 ins
.texture
.out_reg_select
= out_reg
;
1430 /* Setup bias/LOD if necessary. Only register mode support right now.
1431 * TODO: Immediate mode for performance gains */
1433 if (instr
->op
== nir_texop_txb
|| instr
->op
== nir_texop_txl
) {
1434 ins
.texture
.lod_register
= true;
1436 midgard_tex_register_select sel
= {
1446 memcpy(&packed
, &sel
, sizeof(packed
));
1447 ins
.texture
.bias
= packed
;
1450 emit_mir_instruction(ctx
, ins
);
1452 /* Simultaneously alias the destination and emit a move for it. The move will be eliminated if possible */
1454 int o_reg
= REGISTER_TEXTURE_BASE
+ out_reg
, o_index
= nir_dest_index(ctx
, &instr
->dest
);
1455 alias_ssa(ctx
, o_index
, SSA_FIXED_REGISTER(o_reg
));
1456 ctx
->texture_index
[reg
] = o_index
;
1458 midgard_instruction ins2
= v_fmov(SSA_FIXED_REGISTER(o_reg
), blank_alu_src
, o_index
);
1459 emit_mir_instruction(ctx
, ins2
);
1461 /* Used for .cont and .last hinting */
1462 ctx
->texture_op_count
++;
1466 emit_jump(compiler_context
*ctx
, nir_jump_instr
*instr
)
1468 switch (instr
->type
) {
1469 case nir_jump_break
: {
1470 /* Emit a branch out of the loop */
1471 struct midgard_instruction br
= v_branch(false, false);
1472 br
.branch
.target_type
= TARGET_BREAK
;
1473 br
.branch
.target_break
= ctx
->current_loop_depth
;
1474 emit_mir_instruction(ctx
, br
);
1481 DBG("Unknown jump type %d\n", instr
->type
);
1487 emit_instr(compiler_context
*ctx
, struct nir_instr
*instr
)
1489 switch (instr
->type
) {
1490 case nir_instr_type_load_const
:
1491 emit_load_const(ctx
, nir_instr_as_load_const(instr
));
1494 case nir_instr_type_intrinsic
:
1495 emit_intrinsic(ctx
, nir_instr_as_intrinsic(instr
));
1498 case nir_instr_type_alu
:
1499 emit_alu(ctx
, nir_instr_as_alu(instr
));
1502 case nir_instr_type_tex
:
1503 emit_tex(ctx
, nir_instr_as_tex(instr
));
1506 case nir_instr_type_jump
:
1507 emit_jump(ctx
, nir_instr_as_jump(instr
));
1510 case nir_instr_type_ssa_undef
:
1515 DBG("Unhandled instruction type\n");
1521 /* ALU instructions can inline or embed constants, which decreases register
1522 * pressure and saves space. */
1524 #define CONDITIONAL_ATTACH(src) { \
1525 void *entry = _mesa_hash_table_u64_search(ctx->ssa_constants, alu->ssa_args.src + 1); \
1528 attach_constants(ctx, alu, entry, alu->ssa_args.src + 1); \
1529 alu->ssa_args.src = SSA_FIXED_REGISTER(REGISTER_CONSTANT); \
1534 inline_alu_constants(compiler_context
*ctx
)
1536 mir_foreach_instr(ctx
, alu
) {
1537 /* Other instructions cannot inline constants */
1538 if (alu
->type
!= TAG_ALU_4
) continue;
1540 /* If there is already a constant here, we can do nothing */
1541 if (alu
->has_constants
) continue;
1543 /* It makes no sense to inline constants on a branch */
1544 if (alu
->compact_branch
|| alu
->prepacked_branch
) continue;
1546 CONDITIONAL_ATTACH(src0
);
1548 if (!alu
->has_constants
) {
1549 CONDITIONAL_ATTACH(src1
)
1550 } else if (!alu
->inline_constant
) {
1551 /* Corner case: _two_ vec4 constants, for instance with a
1552 * csel. For this case, we can only use a constant
1553 * register for one, we'll have to emit a move for the
1554 * other. Note, if both arguments are constants, then
1555 * necessarily neither argument depends on the value of
1556 * any particular register. As the destination register
1557 * will be wiped, that means we can spill the constant
1558 * to the destination register.
1561 void *entry
= _mesa_hash_table_u64_search(ctx
->ssa_constants
, alu
->ssa_args
.src1
+ 1);
1562 unsigned scratch
= alu
->ssa_args
.dest
;
1565 midgard_instruction ins
= v_fmov(SSA_FIXED_REGISTER(REGISTER_CONSTANT
), blank_alu_src
, scratch
);
1566 attach_constants(ctx
, &ins
, entry
, alu
->ssa_args
.src1
+ 1);
1568 /* Force a break XXX Defer r31 writes */
1569 ins
.unit
= UNIT_VLUT
;
1571 /* Set the source */
1572 alu
->ssa_args
.src1
= scratch
;
1574 /* Inject us -before- the last instruction which set r31 */
1575 mir_insert_instruction_before(mir_prev_op(alu
), ins
);
1581 /* Midgard supports two types of constants, embedded constants (128-bit) and
1582 * inline constants (16-bit). Sometimes, especially with scalar ops, embedded
1583 * constants can be demoted to inline constants, for space savings and
1584 * sometimes a performance boost */
1587 embedded_to_inline_constant(compiler_context
*ctx
)
1589 mir_foreach_instr(ctx
, ins
) {
1590 if (!ins
->has_constants
) continue;
1592 if (ins
->ssa_args
.inline_constant
) continue;
1594 /* Blend constants must not be inlined by definition */
1595 if (ins
->has_blend_constant
) continue;
1597 /* src1 cannot be an inline constant due to encoding
1598 * restrictions. So, if possible we try to flip the arguments
1601 int op
= ins
->alu
.op
;
1603 if (ins
->ssa_args
.src0
== SSA_FIXED_REGISTER(REGISTER_CONSTANT
)) {
1605 /* These ops require an operational change to flip
1606 * their arguments TODO */
1607 case midgard_alu_op_flt
:
1608 case midgard_alu_op_fle
:
1609 case midgard_alu_op_ilt
:
1610 case midgard_alu_op_ile
:
1611 case midgard_alu_op_fcsel
:
1612 case midgard_alu_op_icsel
:
1613 DBG("Missed non-commutative flip (%s)\n", alu_opcode_props
[op
].name
);
1618 if (alu_opcode_props
[op
].props
& OP_COMMUTES
) {
1619 /* Flip the SSA numbers */
1620 ins
->ssa_args
.src0
= ins
->ssa_args
.src1
;
1621 ins
->ssa_args
.src1
= SSA_FIXED_REGISTER(REGISTER_CONSTANT
);
1623 /* And flip the modifiers */
1627 src_temp
= ins
->alu
.src2
;
1628 ins
->alu
.src2
= ins
->alu
.src1
;
1629 ins
->alu
.src1
= src_temp
;
1633 if (ins
->ssa_args
.src1
== SSA_FIXED_REGISTER(REGISTER_CONSTANT
)) {
1634 /* Extract the source information */
1636 midgard_vector_alu_src
*src
;
1637 int q
= ins
->alu
.src2
;
1638 midgard_vector_alu_src
*m
= (midgard_vector_alu_src
*) &q
;
1641 /* Component is from the swizzle, e.g. r26.w -> w component. TODO: What if x is masked out? */
1642 int component
= src
->swizzle
& 3;
1644 /* Scale constant appropriately, if we can legally */
1645 uint16_t scaled_constant
= 0;
1647 if (midgard_is_integer_op(op
)) {
1648 unsigned int *iconstants
= (unsigned int *) ins
->constants
;
1649 scaled_constant
= (uint16_t) iconstants
[component
];
1651 /* Constant overflow after resize */
1652 if (scaled_constant
!= iconstants
[component
])
1655 float original
= (float) ins
->constants
[component
];
1656 scaled_constant
= _mesa_float_to_half(original
);
1658 /* Check for loss of precision. If this is
1659 * mediump, we don't care, but for a highp
1660 * shader, we need to pay attention. NIR
1661 * doesn't yet tell us which mode we're in!
1662 * Practically this prevents most constants
1663 * from being inlined, sadly. */
1665 float fp32
= _mesa_half_to_float(scaled_constant
);
1667 if (fp32
!= original
)
1671 /* We don't know how to handle these with a constant */
1673 if (src
->mod
|| src
->half
|| src
->rep_low
|| src
->rep_high
) {
1674 DBG("Bailing inline constant...\n");
1678 /* Make sure that the constant is not itself a
1679 * vector by checking if all accessed values
1680 * (by the swizzle) are the same. */
1682 uint32_t *cons
= (uint32_t *) ins
->constants
;
1683 uint32_t value
= cons
[component
];
1685 bool is_vector
= false;
1686 unsigned mask
= effective_writemask(&ins
->alu
);
1688 for (int c
= 1; c
< 4; ++c
) {
1689 /* We only care if this component is actually used */
1690 if (!(mask
& (1 << c
)))
1693 uint32_t test
= cons
[(src
->swizzle
>> (2 * c
)) & 3];
1695 if (test
!= value
) {
1704 /* Get rid of the embedded constant */
1705 ins
->has_constants
= false;
1706 ins
->ssa_args
.src1
= SSA_UNUSED_0
;
1707 ins
->ssa_args
.inline_constant
= true;
1708 ins
->inline_constant
= scaled_constant
;
1713 /* Map normal SSA sources to other SSA sources / fixed registers (like
1717 map_ssa_to_alias(compiler_context
*ctx
, int *ref
)
1719 /* Sign is used quite deliberately for unused */
1723 unsigned int alias
= (uintptr_t) _mesa_hash_table_u64_search(ctx
->ssa_to_alias
, *ref
+ 1);
1726 /* Remove entry in leftovers to avoid a redunant fmov */
1728 struct set_entry
*leftover
= _mesa_set_search(ctx
->leftover_ssa_to_alias
, ((void *) (uintptr_t) (*ref
+ 1)));
1731 _mesa_set_remove(ctx
->leftover_ssa_to_alias
, leftover
);
1733 /* Assign the alias map */
1739 /* Basic dead code elimination on the MIR itself, which cleans up e.g. the
1740 * texture pipeline */
1743 midgard_opt_dead_code_eliminate(compiler_context
*ctx
, midgard_block
*block
)
1745 bool progress
= false;
1747 mir_foreach_instr_in_block_safe(block
, ins
) {
1748 if (ins
->type
!= TAG_ALU_4
) continue;
1749 if (ins
->compact_branch
) continue;
1751 if (ins
->ssa_args
.dest
>= SSA_FIXED_MINIMUM
) continue;
1752 if (mir_is_live_after(ctx
, block
, ins
, ins
->ssa_args
.dest
)) continue;
1754 mir_remove_instruction(ins
);
1761 /* Dead code elimination for branches at the end of a block - only one branch
1762 * per block is legal semantically */
1765 midgard_opt_cull_dead_branch(compiler_context
*ctx
, midgard_block
*block
)
1767 bool branched
= false;
1769 mir_foreach_instr_in_block_safe(block
, ins
) {
1770 if (!midgard_is_branch_unit(ins
->unit
)) continue;
1772 /* We ignore prepacked branches since the fragment epilogue is
1773 * just generally special */
1774 if (ins
->prepacked_branch
) continue;
1776 /* Discards are similarly special and may not correspond to the
1779 if (ins
->branch
.target_type
== TARGET_DISCARD
) continue;
1782 /* We already branched, so this is dead */
1783 mir_remove_instruction(ins
);
1791 mir_nontrivial_mod(midgard_vector_alu_src src
, bool is_int
, unsigned mask
)
1794 if (!is_int
&& src
.mod
) return true;
1797 for (unsigned c
= 0; c
< 4; ++c
) {
1798 if (!(mask
& (1 << c
))) continue;
1799 if (((src
.swizzle
>> (2*c
)) & 3) != c
) return true;
1806 mir_nontrivial_source2_mod(midgard_instruction
*ins
)
1808 unsigned mask
= squeeze_writemask(ins
->alu
.mask
);
1809 bool is_int
= midgard_is_integer_op(ins
->alu
.op
);
1811 midgard_vector_alu_src src2
=
1812 vector_alu_from_unsigned(ins
->alu
.src2
);
1814 return mir_nontrivial_mod(src2
, is_int
, mask
);
1818 mir_nontrivial_outmod(midgard_instruction
*ins
)
1820 bool is_int
= midgard_is_integer_op(ins
->alu
.op
);
1821 unsigned mod
= ins
->alu
.outmod
;
1824 return mod
!= midgard_outmod_int_wrap
;
1826 return mod
!= midgard_outmod_none
;
1830 midgard_opt_copy_prop(compiler_context
*ctx
, midgard_block
*block
)
1832 bool progress
= false;
1834 mir_foreach_instr_in_block_safe(block
, ins
) {
1835 if (ins
->type
!= TAG_ALU_4
) continue;
1836 if (!OP_IS_MOVE(ins
->alu
.op
)) continue;
1838 unsigned from
= ins
->ssa_args
.src1
;
1839 unsigned to
= ins
->ssa_args
.dest
;
1841 /* We only work on pure SSA */
1843 if (to
>= SSA_FIXED_MINIMUM
) continue;
1844 if (from
>= SSA_FIXED_MINIMUM
) continue;
1845 if (to
>= ctx
->func
->impl
->ssa_alloc
) continue;
1846 if (from
>= ctx
->func
->impl
->ssa_alloc
) continue;
1848 /* Constant propagation is not handled here, either */
1849 if (ins
->ssa_args
.inline_constant
) continue;
1850 if (ins
->has_constants
) continue;
1852 if (mir_nontrivial_source2_mod(ins
)) continue;
1853 if (mir_nontrivial_outmod(ins
)) continue;
1855 /* We're clear -- rewrite */
1856 mir_rewrite_index_src(ctx
, to
, from
);
1857 mir_remove_instruction(ins
);
1864 /* fmov.pos is an idiom for fpos. Propoagate the .pos up to the source, so then
1865 * the move can be propagated away entirely */
1868 mir_compose_float_outmod(midgard_outmod_float
*outmod
, midgard_outmod_float comp
)
1871 if (comp
== midgard_outmod_none
)
1874 if (*outmod
== midgard_outmod_none
) {
1879 /* TODO: Compose rules */
1884 midgard_opt_pos_propagate(compiler_context
*ctx
, midgard_block
*block
)
1886 bool progress
= false;
1888 mir_foreach_instr_in_block_safe(block
, ins
) {
1889 if (ins
->type
!= TAG_ALU_4
) continue;
1890 if (ins
->alu
.op
!= midgard_alu_op_fmov
) continue;
1891 if (ins
->alu
.outmod
!= midgard_outmod_pos
) continue;
1893 /* TODO: Registers? */
1894 unsigned src
= ins
->ssa_args
.src1
;
1895 if (src
>= ctx
->func
->impl
->ssa_alloc
) continue;
1896 assert(!mir_has_multiple_writes(ctx
, src
));
1898 /* There might be a source modifier, too */
1899 if (mir_nontrivial_source2_mod(ins
)) continue;
1901 /* Backpropagate the modifier */
1902 mir_foreach_instr_in_block_from_rev(block
, v
, mir_prev_op(ins
)) {
1903 if (v
->type
!= TAG_ALU_4
) continue;
1904 if (v
->ssa_args
.dest
!= src
) continue;
1906 /* Can we even take a float outmod? */
1907 if (midgard_is_integer_out_op(v
->alu
.op
)) continue;
1909 midgard_outmod_float temp
= v
->alu
.outmod
;
1910 progress
|= mir_compose_float_outmod(&temp
, ins
->alu
.outmod
);
1912 /* Throw in the towel.. */
1913 if (!progress
) break;
1915 /* Otherwise, transfer the modifier */
1916 v
->alu
.outmod
= temp
;
1917 ins
->alu
.outmod
= midgard_outmod_none
;
1927 midgard_opt_copy_prop_tex(compiler_context
*ctx
, midgard_block
*block
)
1929 bool progress
= false;
1931 mir_foreach_instr_in_block_safe(block
, ins
) {
1932 if (ins
->type
!= TAG_ALU_4
) continue;
1933 if (!OP_IS_MOVE(ins
->alu
.op
)) continue;
1935 unsigned from
= ins
->ssa_args
.src1
;
1936 unsigned to
= ins
->ssa_args
.dest
;
1938 /* Make sure it's simple enough for us to handle */
1940 if (from
>= SSA_FIXED_MINIMUM
) continue;
1941 if (from
>= ctx
->func
->impl
->ssa_alloc
) continue;
1942 if (to
< SSA_FIXED_REGISTER(REGISTER_TEXTURE_BASE
)) continue;
1943 if (to
> SSA_FIXED_REGISTER(REGISTER_TEXTURE_BASE
+ 1)) continue;
1945 bool eliminated
= false;
1947 mir_foreach_instr_in_block_from_rev(block
, v
, mir_prev_op(ins
)) {
1948 /* The texture registers are not SSA so be careful.
1949 * Conservatively, just stop if we hit a texture op
1950 * (even if it may not write) to where we are */
1952 if (v
->type
!= TAG_ALU_4
)
1955 if (v
->ssa_args
.dest
== from
) {
1956 /* We don't want to track partial writes ... */
1957 if (v
->alu
.mask
== 0xF) {
1958 v
->ssa_args
.dest
= to
;
1967 mir_remove_instruction(ins
);
1969 progress
|= eliminated
;
1975 /* The following passes reorder MIR instructions to enable better scheduling */
1978 midgard_pair_load_store(compiler_context
*ctx
, midgard_block
*block
)
1980 mir_foreach_instr_in_block_safe(block
, ins
) {
1981 if (ins
->type
!= TAG_LOAD_STORE_4
) continue;
1983 /* We've found a load/store op. Check if next is also load/store. */
1984 midgard_instruction
*next_op
= mir_next_op(ins
);
1985 if (&next_op
->link
!= &block
->instructions
) {
1986 if (next_op
->type
== TAG_LOAD_STORE_4
) {
1987 /* If so, we're done since we're a pair */
1988 ins
= mir_next_op(ins
);
1992 /* Maximum search distance to pair, to avoid register pressure disasters */
1993 int search_distance
= 8;
1995 /* Otherwise, we have an orphaned load/store -- search for another load */
1996 mir_foreach_instr_in_block_from(block
, c
, mir_next_op(ins
)) {
1997 /* Terminate search if necessary */
1998 if (!(search_distance
--)) break;
2000 if (c
->type
!= TAG_LOAD_STORE_4
) continue;
2002 /* Stores cannot be reordered, since they have
2003 * dependencies. For the same reason, indirect
2004 * loads cannot be reordered as their index is
2005 * loaded in r27.w */
2007 if (OP_IS_STORE(c
->load_store
.op
)) continue;
2009 /* It appears the 0x800 bit is set whenever a
2010 * load is direct, unset when it is indirect.
2011 * Skip indirect loads. */
2013 if (!(c
->load_store
.unknown
& 0x800)) continue;
2015 /* We found one! Move it up to pair and remove it from the old location */
2017 mir_insert_instruction_before(ins
, *c
);
2018 mir_remove_instruction(c
);
2026 /* If there are leftovers after the below pass, emit actual fmov
2027 * instructions for the slow-but-correct path */
2030 emit_leftover_move(compiler_context
*ctx
)
2032 set_foreach(ctx
->leftover_ssa_to_alias
, leftover
) {
2033 int base
= ((uintptr_t) leftover
->key
) - 1;
2036 map_ssa_to_alias(ctx
, &mapped
);
2037 EMIT(fmov
, mapped
, blank_alu_src
, base
);
2042 actualise_ssa_to_alias(compiler_context
*ctx
)
2044 mir_foreach_instr(ctx
, ins
) {
2045 map_ssa_to_alias(ctx
, &ins
->ssa_args
.src0
);
2046 map_ssa_to_alias(ctx
, &ins
->ssa_args
.src1
);
2049 emit_leftover_move(ctx
);
2053 emit_fragment_epilogue(compiler_context
*ctx
)
2055 /* Special case: writing out constants requires us to include the move
2056 * explicitly now, so shove it into r0 */
2058 void *constant_value
= _mesa_hash_table_u64_search(ctx
->ssa_constants
, ctx
->fragment_output
+ 1);
2060 if (constant_value
) {
2061 midgard_instruction ins
= v_fmov(SSA_FIXED_REGISTER(REGISTER_CONSTANT
), blank_alu_src
, SSA_FIXED_REGISTER(0));
2062 attach_constants(ctx
, &ins
, constant_value
, ctx
->fragment_output
+ 1);
2063 emit_mir_instruction(ctx
, ins
);
2066 /* Perform the actual fragment writeout. We have two writeout/branch
2067 * instructions, forming a loop until writeout is successful as per the
2068 * docs. TODO: gl_FragDepth */
2070 EMIT(alu_br_compact_cond
, midgard_jmp_writeout_op_writeout
, TAG_ALU_4
, 0, midgard_condition_always
);
2071 EMIT(alu_br_compact_cond
, midgard_jmp_writeout_op_writeout
, TAG_ALU_4
, -1, midgard_condition_always
);
2074 /* For the blend epilogue, we need to convert the blended fragment vec4 (stored
2075 * in r0) to a RGBA8888 value by scaling and type converting. We then output it
2076 * with the int8 analogue to the fragment epilogue */
2079 emit_blend_epilogue(compiler_context
*ctx
)
2081 /* vmul.fmul.none.fulllow hr48, r0, #255 */
2083 midgard_instruction scale
= {
2086 .inline_constant
= _mesa_float_to_half(255.0),
2088 .src0
= SSA_FIXED_REGISTER(0),
2089 .src1
= SSA_UNUSED_0
,
2090 .dest
= SSA_FIXED_REGISTER(24),
2091 .inline_constant
= true
2094 .op
= midgard_alu_op_fmul
,
2095 .reg_mode
= midgard_reg_mode_32
,
2096 .dest_override
= midgard_dest_override_lower
,
2098 .src1
= vector_alu_srco_unsigned(blank_alu_src
),
2099 .src2
= vector_alu_srco_unsigned(blank_alu_src
),
2103 emit_mir_instruction(ctx
, scale
);
2105 /* vadd.f2u8.pos.low hr0, hr48, #0 */
2107 midgard_vector_alu_src alu_src
= blank_alu_src
;
2108 alu_src
.half
= true;
2110 midgard_instruction f2u8
= {
2113 .src0
= SSA_FIXED_REGISTER(24),
2114 .src1
= SSA_UNUSED_0
,
2115 .dest
= SSA_FIXED_REGISTER(0),
2116 .inline_constant
= true
2119 .op
= midgard_alu_op_f2u8
,
2120 .reg_mode
= midgard_reg_mode_16
,
2121 .dest_override
= midgard_dest_override_lower
,
2122 .outmod
= midgard_outmod_pos
,
2124 .src1
= vector_alu_srco_unsigned(alu_src
),
2125 .src2
= vector_alu_srco_unsigned(blank_alu_src
),
2129 emit_mir_instruction(ctx
, f2u8
);
2131 /* vmul.imov.quarter r0, r0, r0 */
2133 midgard_instruction imov_8
= {
2136 .src0
= SSA_UNUSED_1
,
2137 .src1
= SSA_FIXED_REGISTER(0),
2138 .dest
= SSA_FIXED_REGISTER(0),
2141 .op
= midgard_alu_op_imov
,
2142 .reg_mode
= midgard_reg_mode_8
,
2143 .dest_override
= midgard_dest_override_none
,
2144 .outmod
= midgard_outmod_int_wrap
,
2146 .src1
= vector_alu_srco_unsigned(blank_alu_src
),
2147 .src2
= vector_alu_srco_unsigned(blank_alu_src
),
2151 /* Emit branch epilogue with the 8-bit move as the source */
2153 emit_mir_instruction(ctx
, imov_8
);
2154 EMIT(alu_br_compact_cond
, midgard_jmp_writeout_op_writeout
, TAG_ALU_4
, 0, midgard_condition_always
);
2156 emit_mir_instruction(ctx
, imov_8
);
2157 EMIT(alu_br_compact_cond
, midgard_jmp_writeout_op_writeout
, TAG_ALU_4
, -1, midgard_condition_always
);
2160 static midgard_block
*
2161 emit_block(compiler_context
*ctx
, nir_block
*block
)
2163 midgard_block
*this_block
= calloc(sizeof(midgard_block
), 1);
2164 list_addtail(&this_block
->link
, &ctx
->blocks
);
2166 this_block
->is_scheduled
= false;
2169 ctx
->texture_index
[0] = -1;
2170 ctx
->texture_index
[1] = -1;
2172 /* Add us as a successor to the block we are following */
2173 if (ctx
->current_block
)
2174 midgard_block_add_successor(ctx
->current_block
, this_block
);
2176 /* Set up current block */
2177 list_inithead(&this_block
->instructions
);
2178 ctx
->current_block
= this_block
;
2180 nir_foreach_instr(instr
, block
) {
2181 emit_instr(ctx
, instr
);
2182 ++ctx
->instruction_count
;
2185 inline_alu_constants(ctx
);
2186 embedded_to_inline_constant(ctx
);
2188 /* Perform heavylifting for aliasing */
2189 actualise_ssa_to_alias(ctx
);
2191 midgard_pair_load_store(ctx
, this_block
);
2193 /* Append fragment shader epilogue (value writeout) */
2194 if (ctx
->stage
== MESA_SHADER_FRAGMENT
) {
2195 if (block
== nir_impl_last_block(ctx
->func
->impl
)) {
2197 emit_blend_epilogue(ctx
);
2199 emit_fragment_epilogue(ctx
);
2203 if (block
== nir_start_block(ctx
->func
->impl
))
2204 ctx
->initial_block
= this_block
;
2206 if (block
== nir_impl_last_block(ctx
->func
->impl
))
2207 ctx
->final_block
= this_block
;
2209 /* Allow the next control flow to access us retroactively, for
2211 ctx
->current_block
= this_block
;
2213 /* Document the fallthrough chain */
2214 ctx
->previous_source_block
= this_block
;
2219 static midgard_block
*emit_cf_list(struct compiler_context
*ctx
, struct exec_list
*list
);
2222 emit_if(struct compiler_context
*ctx
, nir_if
*nif
)
2224 /* Conditional branches expect the condition in r31.w; emit a move for
2225 * that in the _previous_ block (which is the current block). */
2226 emit_condition(ctx
, &nif
->condition
, true, COMPONENT_X
);
2228 /* Speculatively emit the branch, but we can't fill it in until later */
2229 EMIT(branch
, true, true);
2230 midgard_instruction
*then_branch
= mir_last_in_block(ctx
->current_block
);
2232 /* Emit the two subblocks */
2233 midgard_block
*then_block
= emit_cf_list(ctx
, &nif
->then_list
);
2235 /* Emit a jump from the end of the then block to the end of the else */
2236 EMIT(branch
, false, false);
2237 midgard_instruction
*then_exit
= mir_last_in_block(ctx
->current_block
);
2239 /* Emit second block, and check if it's empty */
2241 int else_idx
= ctx
->block_count
;
2242 int count_in
= ctx
->instruction_count
;
2243 midgard_block
*else_block
= emit_cf_list(ctx
, &nif
->else_list
);
2244 int after_else_idx
= ctx
->block_count
;
2246 /* Now that we have the subblocks emitted, fix up the branches */
2251 if (ctx
->instruction_count
== count_in
) {
2252 /* The else block is empty, so don't emit an exit jump */
2253 mir_remove_instruction(then_exit
);
2254 then_branch
->branch
.target_block
= after_else_idx
;
2256 then_branch
->branch
.target_block
= else_idx
;
2257 then_exit
->branch
.target_block
= after_else_idx
;
2262 emit_loop(struct compiler_context
*ctx
, nir_loop
*nloop
)
2264 /* Remember where we are */
2265 midgard_block
*start_block
= ctx
->current_block
;
2267 /* Allocate a loop number, growing the current inner loop depth */
2268 int loop_idx
= ++ctx
->current_loop_depth
;
2270 /* Get index from before the body so we can loop back later */
2271 int start_idx
= ctx
->block_count
;
2273 /* Emit the body itself */
2274 emit_cf_list(ctx
, &nloop
->body
);
2276 /* Branch back to loop back */
2277 struct midgard_instruction br_back
= v_branch(false, false);
2278 br_back
.branch
.target_block
= start_idx
;
2279 emit_mir_instruction(ctx
, br_back
);
2281 /* Mark down that branch in the graph. Note that we're really branching
2282 * to the block *after* we started in. TODO: Why doesn't the branch
2283 * itself have an off-by-one then...? */
2284 midgard_block_add_successor(ctx
->current_block
, start_block
->successors
[0]);
2286 /* Find the index of the block about to follow us (note: we don't add
2287 * one; blocks are 0-indexed so we get a fencepost problem) */
2288 int break_block_idx
= ctx
->block_count
;
2290 /* Fix up the break statements we emitted to point to the right place,
2291 * now that we can allocate a block number for them */
2293 list_for_each_entry_from(struct midgard_block
, block
, start_block
, &ctx
->blocks
, link
) {
2294 mir_foreach_instr_in_block(block
, ins
) {
2295 if (ins
->type
!= TAG_ALU_4
) continue;
2296 if (!ins
->compact_branch
) continue;
2297 if (ins
->prepacked_branch
) continue;
2299 /* We found a branch -- check the type to see if we need to do anything */
2300 if (ins
->branch
.target_type
!= TARGET_BREAK
) continue;
2302 /* It's a break! Check if it's our break */
2303 if (ins
->branch
.target_break
!= loop_idx
) continue;
2305 /* Okay, cool, we're breaking out of this loop.
2306 * Rewrite from a break to a goto */
2308 ins
->branch
.target_type
= TARGET_GOTO
;
2309 ins
->branch
.target_block
= break_block_idx
;
2313 /* Now that we've finished emitting the loop, free up the depth again
2314 * so we play nice with recursion amid nested loops */
2315 --ctx
->current_loop_depth
;
2318 static midgard_block
*
2319 emit_cf_list(struct compiler_context
*ctx
, struct exec_list
*list
)
2321 midgard_block
*start_block
= NULL
;
2323 foreach_list_typed(nir_cf_node
, node
, node
, list
) {
2324 switch (node
->type
) {
2325 case nir_cf_node_block
: {
2326 midgard_block
*block
= emit_block(ctx
, nir_cf_node_as_block(node
));
2329 start_block
= block
;
2334 case nir_cf_node_if
:
2335 emit_if(ctx
, nir_cf_node_as_if(node
));
2338 case nir_cf_node_loop
:
2339 emit_loop(ctx
, nir_cf_node_as_loop(node
));
2342 case nir_cf_node_function
:
2351 /* Due to lookahead, we need to report the first tag executed in the command
2352 * stream and in branch targets. An initial block might be empty, so iterate
2353 * until we find one that 'works' */
2356 midgard_get_first_tag_from_block(compiler_context
*ctx
, unsigned block_idx
)
2358 midgard_block
*initial_block
= mir_get_block(ctx
, block_idx
);
2360 unsigned first_tag
= 0;
2363 midgard_bundle
*initial_bundle
= util_dynarray_element(&initial_block
->bundles
, midgard_bundle
, 0);
2365 if (initial_bundle
) {
2366 first_tag
= initial_bundle
->tag
;
2370 /* Initial block is empty, try the next block */
2371 initial_block
= list_first_entry(&(initial_block
->link
), midgard_block
, link
);
2372 } while(initial_block
!= NULL
);
2379 midgard_compile_shader_nir(nir_shader
*nir
, midgard_program
*program
, bool is_blend
)
2381 struct util_dynarray
*compiled
= &program
->compiled
;
2383 midgard_debug
= debug_get_option_midgard_debug();
2385 compiler_context ictx
= {
2387 .stage
= nir
->info
.stage
,
2389 .is_blend
= is_blend
,
2390 .blend_constant_offset
= -1,
2392 .alpha_ref
= program
->alpha_ref
2395 compiler_context
*ctx
= &ictx
;
2397 /* TODO: Decide this at runtime */
2398 ctx
->uniform_cutoff
= 8;
2400 /* Initialize at a global (not block) level hash tables */
2402 ctx
->ssa_constants
= _mesa_hash_table_u64_create(NULL
);
2403 ctx
->ssa_to_alias
= _mesa_hash_table_u64_create(NULL
);
2404 ctx
->hash_to_temp
= _mesa_hash_table_u64_create(NULL
);
2405 ctx
->sysval_to_id
= _mesa_hash_table_u64_create(NULL
);
2406 ctx
->leftover_ssa_to_alias
= _mesa_set_create(NULL
, _mesa_hash_pointer
, _mesa_key_pointer_equal
);
2408 /* Record the varying mapping for the command stream's bookkeeping */
2410 struct exec_list
*varyings
=
2411 ctx
->stage
== MESA_SHADER_VERTEX
? &nir
->outputs
: &nir
->inputs
;
2413 unsigned max_varying
= 0;
2414 nir_foreach_variable(var
, varyings
) {
2415 unsigned loc
= var
->data
.driver_location
;
2416 unsigned sz
= glsl_type_size(var
->type
, FALSE
);
2418 for (int c
= loc
; c
< (loc
+ sz
); ++c
) {
2419 program
->varyings
[c
] = var
->data
.location
;
2420 max_varying
= MAX2(max_varying
, c
);
2424 /* Lower gl_Position pre-optimisation, but after lowering vars to ssa
2425 * (so we don't accidentally duplicate the epilogue since mesa/st has
2426 * messed with our I/O quite a bit already) */
2428 NIR_PASS_V(nir
, nir_lower_vars_to_ssa
);
2430 if (ctx
->stage
== MESA_SHADER_VERTEX
)
2431 NIR_PASS_V(nir
, nir_lower_viewport_transform
);
2433 NIR_PASS_V(nir
, nir_lower_var_copies
);
2434 NIR_PASS_V(nir
, nir_lower_vars_to_ssa
);
2435 NIR_PASS_V(nir
, nir_split_var_copies
);
2436 NIR_PASS_V(nir
, nir_lower_var_copies
);
2437 NIR_PASS_V(nir
, nir_lower_global_vars_to_local
);
2438 NIR_PASS_V(nir
, nir_lower_var_copies
);
2439 NIR_PASS_V(nir
, nir_lower_vars_to_ssa
);
2441 NIR_PASS_V(nir
, nir_lower_io
, nir_var_all
, glsl_type_size
, 0);
2443 /* Optimisation passes */
2447 if (midgard_debug
& MIDGARD_DBG_SHADERS
) {
2448 nir_print_shader(nir
, stdout
);
2451 /* Assign sysvals and counts, now that we're sure
2452 * (post-optimisation) */
2454 midgard_nir_assign_sysvals(ctx
, nir
);
2456 program
->uniform_count
= nir
->num_uniforms
;
2457 program
->sysval_count
= ctx
->sysval_count
;
2458 memcpy(program
->sysvals
, ctx
->sysvals
, sizeof(ctx
->sysvals
[0]) * ctx
->sysval_count
);
2460 program
->attribute_count
= (ctx
->stage
== MESA_SHADER_VERTEX
) ? nir
->num_inputs
: 0;
2461 program
->varying_count
= max_varying
+ 1; /* Fencepost off-by-one */
2463 nir_foreach_function(func
, nir
) {
2467 list_inithead(&ctx
->blocks
);
2468 ctx
->block_count
= 0;
2471 emit_cf_list(ctx
, &func
->impl
->body
);
2472 emit_block(ctx
, func
->impl
->end_block
);
2474 break; /* TODO: Multi-function shaders */
2477 util_dynarray_init(compiled
, NULL
);
2479 /* MIR-level optimizations */
2481 bool progress
= false;
2486 mir_foreach_block(ctx
, block
) {
2487 progress
|= midgard_opt_pos_propagate(ctx
, block
);
2488 progress
|= midgard_opt_copy_prop(ctx
, block
);
2489 progress
|= midgard_opt_copy_prop_tex(ctx
, block
);
2490 progress
|= midgard_opt_dead_code_eliminate(ctx
, block
);
2494 /* Nested control-flow can result in dead branches at the end of the
2495 * block. This messes with our analysis and is just dead code, so cull
2497 mir_foreach_block(ctx
, block
) {
2498 midgard_opt_cull_dead_branch(ctx
, block
);
2502 schedule_program(ctx
);
2504 /* Now that all the bundles are scheduled and we can calculate block
2505 * sizes, emit actual branch instructions rather than placeholders */
2507 int br_block_idx
= 0;
2509 mir_foreach_block(ctx
, block
) {
2510 util_dynarray_foreach(&block
->bundles
, midgard_bundle
, bundle
) {
2511 for (int c
= 0; c
< bundle
->instruction_count
; ++c
) {
2512 midgard_instruction
*ins
= bundle
->instructions
[c
];
2514 if (!midgard_is_branch_unit(ins
->unit
)) continue;
2516 if (ins
->prepacked_branch
) continue;
2518 /* Parse some basic branch info */
2519 bool is_compact
= ins
->unit
== ALU_ENAB_BR_COMPACT
;
2520 bool is_conditional
= ins
->branch
.conditional
;
2521 bool is_inverted
= ins
->branch
.invert_conditional
;
2522 bool is_discard
= ins
->branch
.target_type
== TARGET_DISCARD
;
2524 /* Determine the block we're jumping to */
2525 int target_number
= ins
->branch
.target_block
;
2527 /* Report the destination tag */
2528 int dest_tag
= is_discard
? 0 : midgard_get_first_tag_from_block(ctx
, target_number
);
2530 /* Count up the number of quadwords we're
2531 * jumping over = number of quadwords until
2532 * (br_block_idx, target_number) */
2534 int quadword_offset
= 0;
2537 /* Jump to the end of the shader. We
2538 * need to include not only the
2539 * following blocks, but also the
2540 * contents of our current block (since
2541 * discard can come in the middle of
2544 midgard_block
*blk
= mir_get_block(ctx
, br_block_idx
+ 1);
2546 for (midgard_bundle
*bun
= bundle
+ 1; bun
< (midgard_bundle
*)((char*) block
->bundles
.data
+ block
->bundles
.size
); ++bun
) {
2547 quadword_offset
+= quadword_size(bun
->tag
);
2550 mir_foreach_block_from(ctx
, blk
, b
) {
2551 quadword_offset
+= b
->quadword_count
;
2554 } else if (target_number
> br_block_idx
) {
2557 for (int idx
= br_block_idx
+ 1; idx
< target_number
; ++idx
) {
2558 midgard_block
*blk
= mir_get_block(ctx
, idx
);
2561 quadword_offset
+= blk
->quadword_count
;
2564 /* Jump backwards */
2566 for (int idx
= br_block_idx
; idx
>= target_number
; --idx
) {
2567 midgard_block
*blk
= mir_get_block(ctx
, idx
);
2570 quadword_offset
-= blk
->quadword_count
;
2574 /* Unconditional extended branches (far jumps)
2575 * have issues, so we always use a conditional
2576 * branch, setting the condition to always for
2577 * unconditional. For compact unconditional
2578 * branches, cond isn't used so it doesn't
2579 * matter what we pick. */
2581 midgard_condition cond
=
2582 !is_conditional
? midgard_condition_always
:
2583 is_inverted
? midgard_condition_false
:
2584 midgard_condition_true
;
2586 midgard_jmp_writeout_op op
=
2587 is_discard
? midgard_jmp_writeout_op_discard
:
2588 (is_compact
&& !is_conditional
) ? midgard_jmp_writeout_op_branch_uncond
:
2589 midgard_jmp_writeout_op_branch_cond
;
2592 midgard_branch_extended branch
=
2593 midgard_create_branch_extended(
2598 memcpy(&ins
->branch_extended
, &branch
, sizeof(branch
));
2599 } else if (is_conditional
|| is_discard
) {
2600 midgard_branch_cond branch
= {
2602 .dest_tag
= dest_tag
,
2603 .offset
= quadword_offset
,
2607 assert(branch
.offset
== quadword_offset
);
2609 memcpy(&ins
->br_compact
, &branch
, sizeof(branch
));
2611 assert(op
== midgard_jmp_writeout_op_branch_uncond
);
2613 midgard_branch_uncond branch
= {
2615 .dest_tag
= dest_tag
,
2616 .offset
= quadword_offset
,
2620 assert(branch
.offset
== quadword_offset
);
2622 memcpy(&ins
->br_compact
, &branch
, sizeof(branch
));
2630 /* Emit flat binary from the instruction arrays. Iterate each block in
2631 * sequence. Save instruction boundaries such that lookahead tags can
2632 * be assigned easily */
2634 /* Cache _all_ bundles in source order for lookahead across failed branches */
2636 int bundle_count
= 0;
2637 mir_foreach_block(ctx
, block
) {
2638 bundle_count
+= block
->bundles
.size
/ sizeof(midgard_bundle
);
2640 midgard_bundle
**source_order_bundles
= malloc(sizeof(midgard_bundle
*) * bundle_count
);
2642 mir_foreach_block(ctx
, block
) {
2643 util_dynarray_foreach(&block
->bundles
, midgard_bundle
, bundle
) {
2644 source_order_bundles
[bundle_idx
++] = bundle
;
2648 int current_bundle
= 0;
2650 /* Midgard prefetches instruction types, so during emission we
2651 * need to lookahead. Unless this is the last instruction, in
2652 * which we return 1. Or if this is the second to last and the
2653 * last is an ALU, then it's also 1... */
2655 mir_foreach_block(ctx
, block
) {
2656 mir_foreach_bundle_in_block(block
, bundle
) {
2659 if (current_bundle
+ 1 < bundle_count
) {
2660 uint8_t next
= source_order_bundles
[current_bundle
+ 1]->tag
;
2662 if (!(current_bundle
+ 2 < bundle_count
) && IS_ALU(next
)) {
2669 emit_binary_bundle(ctx
, bundle
, compiled
, lookahead
);
2673 /* TODO: Free deeper */
2674 //util_dynarray_fini(&block->instructions);
2677 free(source_order_bundles
);
2679 /* Report the very first tag executed */
2680 program
->first_tag
= midgard_get_first_tag_from_block(ctx
, 0);
2682 /* Deal with off-by-one related to the fencepost problem */
2683 program
->work_register_count
= ctx
->work_registers
+ 1;
2685 program
->can_discard
= ctx
->can_discard
;
2686 program
->uniform_cutoff
= ctx
->uniform_cutoff
;
2688 program
->blend_patch_offset
= ctx
->blend_constant_offset
;
2690 if (midgard_debug
& MIDGARD_DBG_SHADERS
)
2691 disassemble_midgard(program
->compiled
.data
, program
->compiled
.size
);