[Mesa-dev] [PATCH 20/30] pan/midgard: Use new scheduler
Alyssa Rosenzweig
alyssa.rosenzweig at collabora.com
Sat Sep 28 19:02:25 UTC 2019
We still emit in-order but we switch to using the bundles created from
the new scheduler, which will allow greater flexibility and room for
out-of-order optimization.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig at collabora.com>
---
src/panfrost/midgard/compiler.h | 6 -
src/panfrost/midgard/midgard_compile.c | 103 +---
src/panfrost/midgard/midgard_schedule.c | 699 +++++-------------------
3 files changed, 130 insertions(+), 678 deletions(-)
diff --git a/src/panfrost/midgard/compiler.h b/src/panfrost/midgard/compiler.h
index 60d5b9d0e20..cf943ea6995 100644
--- a/src/panfrost/midgard/compiler.h
+++ b/src/panfrost/midgard/compiler.h
@@ -97,12 +97,6 @@ typedef struct midgard_instruction {
/* I.e. (1 << alu_bit) */
int unit;
- /* When emitting bundle, should this instruction have a break forced
- * before it? Used for r31 writes which are valid only within a single
- * bundle and *need* to happen as early as possible... this is a hack,
- * TODO remove when we have a scheduler */
- bool precede_break;
-
bool has_constants;
uint32_t constants[4];
uint16_t inline_constant;
diff --git a/src/panfrost/midgard/midgard_compile.c b/src/panfrost/midgard/midgard_compile.c
index 337f46f2e0d..f1f8b7ecb9a 100644
--- a/src/panfrost/midgard/midgard_compile.c
+++ b/src/panfrost/midgard/midgard_compile.c
@@ -617,82 +617,6 @@ nir_is_non_scalar_swizzle(nir_alu_src *src, unsigned nr_components)
return false;
}
-/* Midgard puts scalar conditionals in r31.w; move an arbitrary source (the
- * output of a conditional test) into that register */
-
-static void
-emit_condition(compiler_context *ctx, nir_src *src, bool for_branch, unsigned component)
-{
- int condition = nir_src_index(ctx, src);
-
- /* Source to swizzle the desired component into w */
-
- const midgard_vector_alu_src alu_src = {
- .swizzle = SWIZZLE(component, component, component, component),
- };
-
- /* There is no boolean move instruction. Instead, we simulate a move by
- * ANDing the condition with itself to get it into r31.w */
-
- midgard_instruction ins = {
- .type = TAG_ALU_4,
-
- /* We need to set the conditional as close as possible */
- .precede_break = true,
- .unit = for_branch ? UNIT_SMUL : UNIT_SADD,
- .mask = 1 << COMPONENT_W,
- .src = { condition, condition, ~0 },
- .dest = SSA_FIXED_REGISTER(31),
-
- .alu = {
- .op = midgard_alu_op_iand,
- .outmod = midgard_outmod_int_wrap,
- .reg_mode = midgard_reg_mode_32,
- .dest_override = midgard_dest_override_none,
- .src1 = vector_alu_srco_unsigned(alu_src),
- .src2 = vector_alu_srco_unsigned(alu_src)
- },
- };
-
- emit_mir_instruction(ctx, ins);
-}
-
-/* Or, for mixed conditions (with csel_v), here's a vector version using all of
- * r31 instead */
-
-static void
-emit_condition_mixed(compiler_context *ctx, nir_alu_src *src, unsigned nr_comp)
-{
- int condition = nir_src_index(ctx, &src->src);
-
- /* Source to swizzle the desired component into w */
-
- const midgard_vector_alu_src alu_src = {
- .swizzle = SWIZZLE_FROM_ARRAY(src->swizzle),
- };
-
- /* There is no boolean move instruction. Instead, we simulate a move by
- * ANDing the condition with itself to get it into r31.w */
-
- midgard_instruction ins = {
- .type = TAG_ALU_4,
- .precede_break = true,
- .mask = mask_of(nr_comp),
- .src = { condition, condition, ~0 },
- .dest = SSA_FIXED_REGISTER(31),
- .alu = {
- .op = midgard_alu_op_iand,
- .outmod = midgard_outmod_int_wrap,
- .reg_mode = midgard_reg_mode_32,
- .dest_override = midgard_dest_override_none,
- .src1 = vector_alu_srco_unsigned(alu_src),
- .src2 = vector_alu_srco_unsigned(alu_src)
- },
- };
-
- emit_mir_instruction(ctx, ins);
-}
-
#define ALU_CASE(nir, _op) \
case nir_op_##nir: \
op = midgard_alu_op_##_op; \
@@ -980,21 +904,16 @@ emit_alu(compiler_context *ctx, nir_alu_instr *instr)
bool mixed = nir_is_non_scalar_swizzle(&instr->src[0], nr_components);
op = mixed ? midgard_alu_op_icsel_v : midgard_alu_op_icsel;
- /* csel works as a two-arg in Midgard, since the condition is hardcoded in r31.w */
- nr_inputs = 2;
-
- /* Emit the condition into r31 */
-
- if (mixed)
- emit_condition_mixed(ctx, &instr->src[0], nr_components);
- else
- emit_condition(ctx, &instr->src[0].src, false, instr->src[0].swizzle[0]);
-
/* The condition is the first argument; move the other
* arguments up one to be a binary instruction for
- * Midgard */
+ * Midgard with the condition last */
+
+ nir_alu_src temp = instr->src[2];
+
+ instr->src[2] = instr->src[0];
+ instr->src[0] = instr->src[1];
+ instr->src[1] = temp;
- memmove(instr->src, instr->src + 1, 2 * sizeof(nir_alu_src));
break;
}
@@ -1436,10 +1355,6 @@ emit_intrinsic(compiler_context *ctx, nir_intrinsic_instr *instr)
switch (instr->intrinsic) {
case nir_intrinsic_discard_if:
- emit_condition(ctx, &instr->src[0], true, COMPONENT_X);
-
- /* fallthrough */
-
case nir_intrinsic_discard: {
bool conditional = instr->intrinsic == nir_intrinsic_discard_if;
struct midgard_instruction discard = v_branch(conditional, false);
@@ -2301,10 +2216,6 @@ emit_if(struct compiler_context *ctx, nir_if *nif)
{
midgard_block *before_block = ctx->current_block;
- /* Conditional branches expect the condition in r31.w; emit a move for
- * that in the _previous_ block (which is the current block). */
- emit_condition(ctx, &nif->condition, true, COMPONENT_X);
-
/* Speculatively emit the branch, but we can't fill it in until later */
EMIT(branch, true, true);
midgard_instruction *then_branch = mir_last_in_block(ctx->current_block);
diff --git a/src/panfrost/midgard/midgard_schedule.c b/src/panfrost/midgard/midgard_schedule.c
index 6177d0072f7..f883830cf86 100644
--- a/src/panfrost/midgard/midgard_schedule.c
+++ b/src/panfrost/midgard/midgard_schedule.c
@@ -168,22 +168,6 @@ mir_create_dependency_graph(midgard_instruction **instructions, unsigned count,
}
}
-/* Create a mask of accessed components from a swizzle to figure out vector
- * dependencies */
-
-static unsigned
-swizzle_to_access_mask(unsigned swizzle)
-{
- unsigned component_mask = 0;
-
- for (int i = 0; i < 4; ++i) {
- unsigned c = (swizzle >> (2 * i)) & 3;
- component_mask |= (1 << c);
- }
-
- return component_mask;
-}
-
/* Does the mask cover more than a scalar? */
static bool
@@ -199,150 +183,6 @@ is_single_component_mask(unsigned mask)
return components == 1;
}
-/* Checks for an SSA data hazard between two adjacent instructions, keeping in
- * mind that we are a vector architecture and we can write to different
- * components simultaneously */
-
-static bool
-can_run_concurrent_ssa(midgard_instruction *first, midgard_instruction *second)
-{
- /* Writeout has its own rules anyway */
- if (first->compact_branch || second->compact_branch)
- return true;
-
- /* Each instruction reads some registers and writes to a register. See
- * where the first writes */
-
- int source = first->dest;
- int source_mask = first->mask;
-
- /* As long as the second doesn't read from the first, we're okay */
- for (unsigned i = 0; i < ARRAY_SIZE(second->src); ++i) {
- if (second->src[i] != source)
- continue;
-
- if (first->type != TAG_ALU_4)
- return false;
-
- /* Figure out which components we just read from */
-
- int q = (i == 0) ? second->alu.src1 : second->alu.src2;
- midgard_vector_alu_src *m = (midgard_vector_alu_src *) &q;
-
- /* Check if there are components in common, and fail if so */
- if (swizzle_to_access_mask(m->swizzle) & source_mask)
- return false;
- }
-
- /* Otherwise, it's safe in that regard. Another data hazard is both
- * writing to the same place, of course */
-
- if (second->dest == source) {
- /* ...but only if the components overlap */
-
- if (second->mask & source_mask)
- return false;
- }
-
- /* ...That's it */
- return true;
-}
-
-static bool
-midgard_has_hazard(
- midgard_instruction **segment, unsigned segment_size,
- midgard_instruction *ains)
-{
- for (int s = 0; s < segment_size; ++s)
- if (!can_run_concurrent_ssa(segment[s], ains))
- return true;
-
- return false;
-
-
-}
-
-/* Fragment writeout (of r0) is allowed when:
- *
- * - All components of r0 are written in the bundle
- * - No components of r0 are written in VLUT
- * - Non-pipelined dependencies of r0 are not written in the bundle
- *
- * This function checks if these requirements are satisfied given the content
- * of a scheduled bundle.
- */
-
-static bool
-can_writeout_fragment(compiler_context *ctx, midgard_instruction **bundle, unsigned count, unsigned node_count, unsigned r0)
-{
- /* First scan for which components of r0 are written out. Initially
- * none are written */
-
- uint8_t r0_written_mask = 0x0;
-
- /* Simultaneously we scan for the set of dependencies */
-
- size_t sz = sizeof(BITSET_WORD) * BITSET_WORDS(node_count);
- BITSET_WORD *dependencies = calloc(1, sz);
- memset(dependencies, 0, sz);
-
- bool success = false;
-
- for (unsigned i = 0; i < count; ++i) {
- midgard_instruction *ins = bundle[i];
-
- if (ins->dest != r0)
- continue;
-
- /* Record written out mask */
- r0_written_mask |= ins->mask;
-
- /* Record dependencies, but only if they won't become pipeline
- * registers. We know we can't be live after this, because
- * we're writeout at the very end of the shader. So check if
- * they were written before us. */
-
- unsigned src0 = ins->src[0];
- unsigned src1 = ins->src[1];
-
- if (!mir_is_written_before(ctx, bundle[0], src0))
- src0 = ~0;
-
- if (!mir_is_written_before(ctx, bundle[0], src1))
- src1 = ~0;
-
- if (src0 < node_count)
- BITSET_SET(dependencies, src0);
-
- if (src1 < node_count)
- BITSET_SET(dependencies, src1);
-
- /* Requirement 2 */
- if (ins->unit == UNIT_VLUT)
- goto done;
- }
-
- /* Requirement 1 */
- if ((r0_written_mask & 0xF) != 0xF)
- goto done;
-
- /* Requirement 3 */
-
- for (unsigned i = 0; i < count; ++i) {
- unsigned dest = bundle[i]->dest;
-
- if (dest < node_count && BITSET_TEST(dependencies, dest))
- goto done;
- }
-
- /* Otherwise, we're good to go */
- success = true;
-
-done:
- free(dependencies);
- return success;
-}
-
/* Helpers for scheudling */
static bool
@@ -399,340 +239,6 @@ bytes_for_instruction(midgard_instruction *ains)
return sizeof(midgard_reg_info) + sizeof(midgard_scalar_alu);
}
-/* Schedules, but does not emit, a single basic block. After scheduling, the
- * final tag and size of the block are known, which are necessary for branching
- * */
-
-static midgard_bundle
-schedule_bundle(compiler_context *ctx, midgard_block *block, midgard_instruction *ins, int *skip)
-{
- int instructions_emitted = 0, packed_idx = 0;
- midgard_bundle bundle = { 0 };
-
- midgard_instruction *scheduled[5] = { NULL };
-
- uint8_t tag = ins->type;
-
- /* Default to the instruction's tag */
- bundle.tag = tag;
-
- switch (ins->type) {
- case TAG_ALU_4: {
- uint32_t control = 0;
- size_t bytes_emitted = sizeof(control);
-
- /* TODO: Constant combining */
- int index = 0, last_unit = 0;
-
- /* Previous instructions, for the purpose of parallelism */
- midgard_instruction *segment[4] = {0};
- int segment_size = 0;
-
- instructions_emitted = -1;
- midgard_instruction *pins = ins;
-
- unsigned constant_count = 0;
-
- for (;;) {
- midgard_instruction *ains = pins;
-
- /* Advance instruction pointer */
- if (index) {
- ains = mir_next_op(pins);
- pins = ains;
- }
-
- /* Out-of-work condition */
- if ((struct list_head *) ains == &block->instructions)
- break;
-
- /* Ensure that the chain can continue */
- if (ains->type != TAG_ALU_4) break;
-
- /* If there's already something in the bundle and we
- * have weird scheduler constraints, break now */
- if (ains->precede_break && index) break;
-
- /* According to the presentation "The ARM
- * Mali-T880 Mobile GPU" from HotChips 27,
- * there are two pipeline stages. Branching
- * position determined experimentally. Lines
- * are executed in parallel:
- *
- * [ VMUL ] [ SADD ]
- * [ VADD ] [ SMUL ] [ LUT ] [ BRANCH ]
- *
- * Verify that there are no ordering dependencies here.
- *
- * TODO: Allow for parallelism!!!
- */
-
- /* Pick a unit for it if it doesn't force a particular unit */
-
- int unit = ains->unit;
-
- if (!unit) {
- int op = ains->alu.op;
- int units = alu_opcode_props[op].props;
- bool scalar = mir_is_scalar(ains);
-
- if (!scalar) {
- if (last_unit >= UNIT_VADD) {
- if (units & UNIT_VLUT)
- unit = UNIT_VLUT;
- else
- break;
- } else {
- if ((units & UNIT_VMUL) && last_unit < UNIT_VMUL)
- unit = UNIT_VMUL;
- else if ((units & UNIT_VADD) && !(control & UNIT_VADD))
- unit = UNIT_VADD;
- else if (units & UNIT_VLUT)
- unit = UNIT_VLUT;
- else
- break;
- }
- } else {
- if (last_unit >= UNIT_VADD) {
- if ((units & UNIT_SMUL) && !(control & UNIT_SMUL))
- unit = UNIT_SMUL;
- else if (units & UNIT_VLUT)
- unit = UNIT_VLUT;
- else
- break;
- } else {
- if ((units & UNIT_VMUL) && (last_unit < UNIT_VMUL))
- unit = UNIT_VMUL;
- else if ((units & UNIT_SADD) && !(control & UNIT_SADD) && !midgard_has_hazard(segment, segment_size, ains))
- unit = UNIT_SADD;
- else if (units & UNIT_VADD)
- unit = UNIT_VADD;
- else if (units & UNIT_SMUL)
- unit = UNIT_SMUL;
- else if (units & UNIT_VLUT)
- unit = UNIT_VLUT;
- else
- break;
- }
- }
-
- assert(unit & units);
- }
-
- /* Late unit check, this time for encoding (not parallelism) */
- if (unit <= last_unit) break;
-
- /* Clear the segment */
- if (last_unit < UNIT_VADD && unit >= UNIT_VADD)
- segment_size = 0;
-
- if (midgard_has_hazard(segment, segment_size, ains))
- break;
-
- /* We're good to go -- emit the instruction */
- ains->unit = unit;
-
- segment[segment_size++] = ains;
-
- /* We try to reuse constants if possible, by adjusting
- * the swizzle */
-
- if (ains->has_blend_constant) {
- /* Everything conflicts with the blend constant */
- if (bundle.has_embedded_constants)
- break;
-
- bundle.has_blend_constant = 1;
- bundle.has_embedded_constants = 1;
- } else if (ains->has_constants && ains->alu.reg_mode == midgard_reg_mode_16) {
- /* TODO: DRY with the analysis pass */
-
- if (bundle.has_blend_constant)
- break;
-
- if (constant_count)
- break;
-
- /* TODO: Fix packing XXX */
- uint16_t *bundles = (uint16_t *) bundle.constants;
- uint32_t *constants = (uint32_t *) ains->constants;
-
- /* Copy them wholesale */
- for (unsigned i = 0; i < 4; ++i)
- bundles[i] = constants[i];
-
- bundle.has_embedded_constants = true;
- constant_count = 4;
- } else if (ains->has_constants) {
- /* By definition, blend constants conflict with
- * everything, so if there are already
- * constants we break the bundle *now* */
-
- if (bundle.has_blend_constant)
- break;
-
- /* For anything but blend constants, we can do
- * proper analysis, however */
-
- /* TODO: Mask by which are used */
- uint32_t *constants = (uint32_t *) ains->constants;
- uint32_t *bundles = (uint32_t *) bundle.constants;
-
- uint32_t indices[4] = { 0 };
- bool break_bundle = false;
-
- for (unsigned i = 0; i < 4; ++i) {
- uint32_t cons = constants[i];
- bool constant_found = false;
-
- /* Search for the constant */
- for (unsigned j = 0; j < constant_count; ++j) {
- if (bundles[j] != cons)
- continue;
-
- /* We found it, reuse */
- indices[i] = j;
- constant_found = true;
- break;
- }
-
- if (constant_found)
- continue;
-
- /* We didn't find it, so allocate it */
- unsigned idx = constant_count++;
-
- if (idx >= 4) {
- /* Uh-oh, out of space */
- break_bundle = true;
- break;
- }
-
- /* We have space, copy it in! */
- bundles[idx] = cons;
- indices[i] = idx;
- }
-
- if (break_bundle)
- break;
-
- /* Cool, we have it in. So use indices as a
- * swizzle */
-
- unsigned swizzle = SWIZZLE_FROM_ARRAY(indices);
- unsigned r_constant = SSA_FIXED_REGISTER(REGISTER_CONSTANT);
-
- if (ains->src[0] == r_constant)
- ains->alu.src1 = vector_alu_apply_swizzle(ains->alu.src1, swizzle);
-
- if (ains->src[1] == r_constant)
- ains->alu.src2 = vector_alu_apply_swizzle(ains->alu.src2, swizzle);
-
- bundle.has_embedded_constants = true;
- }
-
- if (ains->compact_branch) {
- /* All of r0 has to be written out along with
- * the branch writeout */
-
- if (ains->writeout && !can_writeout_fragment(ctx, scheduled, index, ctx->temp_count, ains->src[0])) {
- /* We only work on full moves
- * at the beginning. We could
- * probably do better */
- if (index != 0)
- break;
-
- /* Inject a move */
- midgard_instruction ins = v_mov(0, blank_alu_src, SSA_FIXED_REGISTER(0));
- ins.unit = UNIT_VMUL;
- control |= ins.unit;
-
- /* TODO don't leak */
- midgard_instruction *move =
- mem_dup(&ins, sizeof(midgard_instruction));
- bytes_emitted += bytes_for_instruction(move);
- bundle.instructions[packed_idx++] = move;
- }
- }
-
- bytes_emitted += bytes_for_instruction(ains);
-
- /* Defer marking until after writing to allow for break */
- scheduled[index] = ains;
- control |= ains->unit;
- last_unit = ains->unit;
- ++instructions_emitted;
- ++index;
- }
-
- int padding = 0;
-
- /* Pad ALU op to nearest word */
-
- if (bytes_emitted & 15) {
- padding = 16 - (bytes_emitted & 15);
- bytes_emitted += padding;
- }
-
- /* Constants must always be quadwords */
- if (bundle.has_embedded_constants)
- bytes_emitted += 16;
-
- /* Size ALU instruction for tag */
- bundle.tag = (TAG_ALU_4) + (bytes_emitted / 16) - 1;
- bundle.padding = padding;
- bundle.control = bundle.tag | control;
-
- break;
- }
-
- case TAG_LOAD_STORE_4: {
- /* Load store instructions have two words at once. If
- * we only have one queued up, we need to NOP pad.
- * Otherwise, we store both in succession to save space
- * and cycles -- letting them go in parallel -- skip
- * the next. The usefulness of this optimisation is
- * greatly dependent on the quality of the instruction
- * scheduler.
- */
-
- midgard_instruction *next_op = mir_next_op(ins);
-
- if ((struct list_head *) next_op != &block->instructions && next_op->type == TAG_LOAD_STORE_4) {
- /* TODO: Concurrency check */
- instructions_emitted++;
- }
-
- break;
- }
-
- case TAG_TEXTURE_4: {
- /* Which tag we use depends on the shader stage */
- bool in_frag = ctx->stage == MESA_SHADER_FRAGMENT;
- bundle.tag = in_frag ? TAG_TEXTURE_4 : TAG_TEXTURE_4_VTX;
- break;
- }
-
- default:
- unreachable("Unknown tag");
- break;
- }
-
- /* Copy the instructions into the bundle */
- bundle.instruction_count = instructions_emitted + 1 + packed_idx;
-
- midgard_instruction *uins = ins;
- for (; packed_idx < bundle.instruction_count; ++packed_idx) {
- assert(&uins->link != &block->instructions);
- bundle.instructions[packed_idx] = uins;
- uins = mir_next_op(uins);
- }
-
- *skip = instructions_emitted;
-
- return bundle;
-}
-
/* We would like to flatten the linked list of midgard_instructions in a bundle
* to an array of pointers on the heap for easy indexing */
@@ -925,6 +431,9 @@ mir_choose_instruction(
if (branch && !instructions[i]->compact_branch)
continue;
+ if (alu && !mir_adjust_constants(instructions[i], predicate, false))
+ continue;
+
/* Simulate in-order scheduling */
if ((signed) i < best_index)
continue;
@@ -943,6 +452,9 @@ mir_choose_instruction(
if (predicate->destructive) {
BITSET_CLEAR(worklist, best_index);
+
+ if (alu)
+ mir_adjust_constants(instructions[best_index], predicate, true);
}
return instructions[best_index];
@@ -1215,12 +727,10 @@ mir_schedule_alu(
struct midgard_predicate predicate = {
.tag = TAG_ALU_4,
.destructive = true,
- .exclude = ~0
+ .exclude = ~0,
+ .constants = (uint8_t *) bundle.constants
};
- midgard_instruction *ins =
- mir_choose_instruction(instructions, worklist, len, &predicate);
-
midgard_instruction *vmul = NULL;
midgard_instruction *vadd = NULL;
midgard_instruction *vlut = NULL;
@@ -1228,88 +738,92 @@ mir_schedule_alu(
midgard_instruction *sadd = NULL;
midgard_instruction *branch = NULL;
- mir_update_worklist(worklist, len, instructions, ins);
+ mir_choose_alu(&branch, instructions, worklist, len, &predicate, ALU_ENAB_BR_COMPACT);
+ mir_update_worklist(worklist, len, instructions, branch);
+ bool writeout = branch && branch->writeout;
- if (ins->compact_branch) {
- branch = ins;
- } else if (!ins->unit) {
- unsigned units = alu_opcode_props[ins->alu.op].props;
-
- if (units & UNIT_VMUL) {
- ins->unit = UNIT_VMUL;
- vmul = ins;
- } else if (units & UNIT_VADD) {
- ins->unit = UNIT_VADD;
- vadd = ins;
- } else if (units & UNIT_VLUT) {
- ins->unit = UNIT_VLUT;
- vlut = ins;
- } else
- assert(0);
+ if (branch && !branch->prepacked_branch && branch->branch.conditional) {
+ midgard_instruction *cond = mir_schedule_condition(ctx, &predicate, worklist, len, instructions, branch);
+
+ if (cond->unit == UNIT_VADD)
+ vadd = cond;
+ else if (cond->unit == UNIT_SMUL)
+ smul = cond;
+ else
+ unreachable("Bad condition");
}
- bundle.has_embedded_constants = ins->has_constants;
- bundle.has_blend_constant = ins->has_blend_constant;
+ if (!writeout)
+ mir_choose_alu(&vlut, instructions, worklist, len, &predicate, UNIT_VLUT);
- if (ins->alu.reg_mode == midgard_reg_mode_16) {
- /* TODO: Fix packing XXX */
- uint16_t *bundles = (uint16_t *) bundle.constants;
- uint32_t *constants = (uint32_t *) ins->constants;
+ mir_choose_alu(&vadd, instructions, worklist, len, &predicate, UNIT_VADD);
+
+ mir_update_worklist(worklist, len, instructions, vlut);
+ mir_update_worklist(worklist, len, instructions, vadd);
+ mir_update_worklist(worklist, len, instructions, smul);
- /* Copy them wholesale */
- for (unsigned i = 0; i < 4; ++i)
- bundles[i] = constants[i];
- } else {
- memcpy(bundle.constants, ins->constants, sizeof(bundle.constants));
+ bool vadd_csel = vadd && OP_IS_CSEL(vadd->alu.op);
+ bool smul_csel = smul && OP_IS_CSEL(smul->alu.op);
+
+ if (vadd_csel || smul_csel) {
+ midgard_instruction *ins = vadd_csel ? vadd : smul;
+ midgard_instruction *cond = mir_schedule_condition(ctx, &predicate, worklist, len, instructions, ins);
+
+ if (cond->unit == UNIT_VMUL)
+ vmul = cond;
+ else if (cond->unit == UNIT_SADD)
+ sadd = cond;
+ else
+ unreachable("Bad condition");
}
- if (ins->writeout) {
- unsigned src = (branch->src[0] == ~0) ? SSA_FIXED_REGISTER(0) : branch->src[0];
- unsigned temp = (branch->src[0] == ~0) ? SSA_FIXED_REGISTER(0) : make_compiler_temp(ctx);
- midgard_instruction mov = v_mov(src, blank_alu_src, temp);
- vmul = mem_dup(&mov, sizeof(midgard_instruction));
- vmul->unit = UNIT_VMUL;
- vmul->mask = 0xF;
- /* TODO: Don't leak */
-
- /* Rewrite to use our temp */
+ /* Check if writeout reads its own register */
+ bool bad_writeout = false;
+
+ if (branch && branch->writeout) {
midgard_instruction *stages[] = { sadd, vadd, smul };
+ unsigned src = (branch->src[0] == ~0) ? SSA_FIXED_REGISTER(0) : branch->src[0];
+ unsigned writeout_mask = 0x0;
for (unsigned i = 0; i < ARRAY_SIZE(stages); ++i) {
- if (stages[i])
- mir_rewrite_index_dst_single(stages[i], src, temp);
+ if (!stages[i])
+ continue;
+
+ if (stages[i]->dest != src)
+ continue;
+
+ writeout_mask |= stages[i]->mask;
+ bad_writeout |= mir_has_arg(stages[i], branch->src[0]);
}
- mir_rewrite_index_src_single(branch, src, temp);
- }
+ /* Add a move if necessary */
+ if (bad_writeout || writeout_mask != 0xF) {
+ unsigned temp = (branch->src[0] == ~0) ? SSA_FIXED_REGISTER(0) : make_compiler_temp(ctx);
+ midgard_instruction mov = v_mov(src, blank_alu_src, temp);
+ vmul = mem_dup(&mov, sizeof(midgard_instruction));
+ vmul->unit = UNIT_VMUL;
+ vmul->mask = 0xF ^ writeout_mask;
+ /* TODO: Don't leak */
- if ((vadd && OP_IS_CSEL(vadd->alu.op)) || (smul && OP_IS_CSEL(smul->alu.op)) || (ins->compact_branch && !ins->prepacked_branch && ins->branch.conditional)) {
- midgard_instruction *cond = mir_choose_instruction(instructions, worklist, len, &predicate);
- mir_update_worklist(worklist, len, instructions, cond);
+ /* Rewrite to use our temp */
- if (!cond->unit) {
- unsigned units = alu_opcode_props[cond->alu.op].props;
+ for (unsigned i = 0; i < ARRAY_SIZE(stages); ++i) {
+ if (stages[i])
+ mir_rewrite_index_dst_single(stages[i], src, temp);
+ }
- if (units & UNIT_VMUL) {
- cond->unit = UNIT_VMUL;
- } else if (units & UNIT_VADD) {
- cond->unit = UNIT_VADD;
- } else
- assert(0);
+ mir_rewrite_index_src_single(branch, src, temp);
}
-
- if (cond->unit & UNIT_VMUL)
- vmul = cond;
- else if (cond->unit & UNIT_SADD)
- sadd = cond;
- else if (cond->unit & UNIT_VADD)
- vadd = cond;
- else if (cond->unit & UNIT_SMUL)
- smul = cond;
- else
- unreachable("Bad condition");
}
+ mir_choose_alu(&vmul, instructions, worklist, len, &predicate, UNIT_VMUL);
+
+ mir_update_worklist(worklist, len, instructions, vmul);
+ mir_update_worklist(worklist, len, instructions, sadd);
+
+ bundle.has_blend_constant = predicate.blend_constant;
+ bundle.has_embedded_constants = predicate.constant_count > 0;
+
unsigned padding = 0;
/* Now that we have finished scheduling, build up the bundle */
@@ -1353,6 +867,9 @@ schedule_block(compiler_context *ctx, midgard_block *block)
unsigned len = 0;
midgard_instruction **instructions = flatten_mir(block, &len);
+ if (!len)
+ return;
+
/* Calculate dependencies and initial worklist */
unsigned node_count = ctx->temp_count + 1;
mir_create_dependency_graph(instructions, len, node_count);
@@ -1362,30 +879,60 @@ schedule_block(compiler_context *ctx, midgard_block *block)
BITSET_WORD *worklist = calloc(sz, 1);
mir_initialize_worklist(worklist, instructions, len);
- util_dynarray_init(&block->bundles, NULL);
+ struct util_dynarray bundles;
+ util_dynarray_init(&bundles, NULL);
block->quadword_count = 0;
+ unsigned blend_offset = 0;
+
+ for (;;) {
+ unsigned tag = mir_choose_bundle(instructions, worklist, len);
+ midgard_bundle bundle;
+
+ if (tag == TAG_TEXTURE_4)
+ bundle = mir_schedule_texture(instructions, worklist, len);
+ else if (tag == TAG_LOAD_STORE_4)
+ bundle = mir_schedule_ldst(instructions, worklist, len);
+ else if (tag == TAG_ALU_4)
+ bundle = mir_schedule_alu(ctx, instructions, worklist, len);
+ else
+ break;
- int skip = 0;
- mir_foreach_instr_in_block(block, ins) {
- if (skip) {
- skip--;
- continue;
- }
-
- midgard_bundle bundle = schedule_bundle(ctx, block, ins, &skip);
- util_dynarray_append(&block->bundles, midgard_bundle, bundle);
+ util_dynarray_append(&bundles, midgard_bundle, bundle);
- if (bundle.has_blend_constant) {
- unsigned offset = ctx->quadword_count + block->quadword_count + quadword_size(bundle.tag) - 1;
- ctx->blend_constant_offset = offset * 0x10;
- }
+ if (bundle.has_blend_constant)
+ blend_offset = block->quadword_count;
block->quadword_count += quadword_size(bundle.tag);
}
+ /* We emitted bundles backwards; copy into the block in reverse-order */
+
+ util_dynarray_init(&block->bundles, NULL);
+ util_dynarray_foreach_reverse(&bundles, midgard_bundle, bundle) {
+ util_dynarray_append(&block->bundles, midgard_bundle, *bundle);
+ }
+
+ /* Blend constant was backwards as well. blend_offset if set is
+ * strictly positive, as an offset of zero would imply constants before
+ * any instructions which is invalid in Midgard */
+
+ if (blend_offset)
+ ctx->blend_constant_offset = ((ctx->quadword_count + block->quadword_count) - blend_offset - 1) * 0x10;
+
block->is_scheduled = true;
ctx->quadword_count += block->quadword_count;
+
+ /* Reorder instructions to match bundled. First remove existing
+ * instructions and then recreate the list */
+
+ mir_foreach_instr_in_block_safe(block, ins) {
+ list_del(&ins->link);
+ }
+
+ mir_foreach_instr_in_block_scheduled_rev(block, ins) {
+ list_add(&ins->link, &block->instructions);
+ }
}
/* When we're 'squeezing down' the values in the IR, we maintain a hash
--
2.23.0
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