[Mesa-dev] [PATCH 08/15] i965/vec4: Use MOV_INDIRECT instead of reladdr for indirect push constants
Jason Ekstrand
jason at jlekstrand.net
Wed Dec 9 20:23:52 PST 2015
This commit moves us to an instruction based model rather than a
register-based model for indirects. This is more accurate anyway as we
have to emit instructions to resolve the reladdr. It's also a lot simpler
because it gets rid of the recursive reladdr problem by design.
One side-effect of this is that we need a whole new algorithm in
move_uniform_array_access_to_pull_constants. This new algorithm is much
more straightforward than the old one and is fairly similar to what we're
already doing in the FS backend.
---
src/mesa/drivers/dri/i965/brw_vec4.cpp | 2 +-
src/mesa/drivers/dri/i965/brw_vec4.h | 3 +-
src/mesa/drivers/dri/i965/brw_vec4_nir.cpp | 10 +--
src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp | 86 ++++++++++++--------------
4 files changed, 50 insertions(+), 51 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/brw_vec4.cpp b/src/mesa/drivers/dri/i965/brw_vec4.cpp
index a697bdf..e4a405b 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4.cpp
@@ -775,7 +775,7 @@ vec4_visitor::move_push_constants_to_pull_constants()
dst_reg temp = dst_reg(this, glsl_type::vec4_type);
emit_pull_constant_load(block, inst, temp, inst->src[i],
- pull_constant_loc[uniform]);
+ pull_constant_loc[uniform], src_reg());
inst->src[i].file = temp.file;
inst->src[i].nr = temp.nr;
diff --git a/src/mesa/drivers/dri/i965/brw_vec4.h b/src/mesa/drivers/dri/i965/brw_vec4.h
index f2e5ce1..e6d6c82 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4.h
+++ b/src/mesa/drivers/dri/i965/brw_vec4.h
@@ -293,7 +293,8 @@ public:
void emit_pull_constant_load(bblock_t *block, vec4_instruction *inst,
dst_reg dst,
src_reg orig_src,
- int base_offset);
+ int base_offset,
+ src_reg indirect);
void emit_pull_constant_load_reg(dst_reg dst,
src_reg surf_index,
src_reg offset,
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
index f965b39..58b6612 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
@@ -673,12 +673,14 @@ vec4_visitor::nir_emit_intrinsic(nir_intrinsic_instr *instr)
/* Offsets are in bytes but they should always be multiples of 16 */
assert(const_offset->u[0] % 16 == 0);
src.reg_offset = const_offset->u[0] / 16;
+
+ emit(MOV(dest, src));
} else {
- src_reg tmp = get_nir_src(instr->src[0], BRW_REGISTER_TYPE_D, 1);
- src.reladdr = new(mem_ctx) src_reg(tmp);
- }
+ src_reg indirect = get_nir_src(instr->src[0], BRW_REGISTER_TYPE_UD, 1);
- emit(MOV(dest, src));
+ emit(SHADER_OPCODE_MOV_INDIRECT, dest, src,
+ indirect, brw_imm_ud(instr->const_index[1]));
+ }
break;
}
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
index 7712d34..e7ab536 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
@@ -1641,16 +1641,16 @@ vec4_visitor::move_grf_array_access_to_scratch()
void
vec4_visitor::emit_pull_constant_load(bblock_t *block, vec4_instruction *inst,
dst_reg temp, src_reg orig_src,
- int base_offset)
+ int base_offset, src_reg indirect)
{
int reg_offset = base_offset + orig_src.reg_offset;
const unsigned index = prog_data->base.binding_table.pull_constants_start;
src_reg offset;
- if (orig_src.reladdr) {
+ if (indirect.file != BAD_FILE) {
offset = src_reg(this, glsl_type::int_type);
- emit_before(block, inst, ADD(dst_reg(offset), *orig_src.reladdr,
+ emit_before(block, inst, ADD(dst_reg(offset), indirect,
brw_imm_d(reg_offset * 16)));
} else if (devinfo->gen >= 8) {
/* Store the offset in a GRF so we can send-from-GRF. */
@@ -1685,59 +1685,55 @@ vec4_visitor::move_uniform_array_access_to_pull_constants()
{
int pull_constant_loc[this->uniforms];
memset(pull_constant_loc, -1, sizeof(pull_constant_loc));
- bool nested_reladdr;
- /* Walk through and find array access of uniforms. Put a copy of that
- * uniform in the pull constant buffer.
- *
- * Note that we don't move constant-indexed accesses to arrays. No
- * testing has been done of the performance impact of this choice.
+ /* First, walk through the instructions and determine which things need to
+ * be pulled. We mark something as needing to bye pulled by setting
+ * pull_constant_loc to 0.
*/
- do {
- nested_reladdr = false;
-
- foreach_block_and_inst_safe(block, vec4_instruction, inst, cfg) {
- for (int i = 0 ; i < 3; i++) {
- if (inst->src[i].file != UNIFORM || !inst->src[i].reladdr)
- continue;
+ foreach_block_and_inst(block, vec4_instruction, inst, cfg) {
+ /* We only care about MOV_INDIRECT of a uniform */
+ if (inst->opcode != SHADER_OPCODE_MOV_INDIRECT ||
+ inst->src[0].file != UNIFORM)
+ continue;
- int uniform = inst->src[i].nr;
+ int uniform_nr = inst->src[0].nr + inst->src[0].reg_offset;
- if (inst->src[i].reladdr->reladdr)
- nested_reladdr = true; /* will need another pass */
+ for (unsigned j = 0; j < DIV_ROUND_UP(inst->src[2].ud, 16); j++)
+ pull_constant_loc[uniform_nr + j] = 0;
+ }
- /* If this array isn't already present in the pull constant buffer,
- * add it.
- */
- if (pull_constant_loc[uniform] == -1) {
- const gl_constant_value **values =
- &stage_prog_data->param[uniform * 4];
+ /* Next, we walk the list of uniforms and assign real pull constant
+ * locations and set their corresponding entries in pull_param.
+ */
+ for (int j = 0; j < this->uniforms; j++) {
+ if (pull_constant_loc[j] < 0)
+ continue;
- pull_constant_loc[uniform] = stage_prog_data->nr_pull_params / 4;
+ pull_constant_loc[j] = stage_prog_data->nr_pull_params / 4;
- assert(uniform < uniform_array_size);
- for (int j = 0; j < uniform_size[uniform] * 4; j++) {
- stage_prog_data->pull_param[stage_prog_data->nr_pull_params++]
- = values[j];
- }
- }
+ for (int i = 0; i < 4; i++) {
+ stage_prog_data->pull_param[stage_prog_data->nr_pull_params++]
+ = stage_prog_data->param[j * 4 + i];
+ }
+ }
- /* Set up the annotation tracking for new generated instructions. */
- base_ir = inst->ir;
- current_annotation = inst->annotation;
+ /* Finally, we can walk through the instructions and lower MOV_INDIRECT
+ * instructions to actual uniform pulls.
+ */
+ foreach_block_and_inst_safe(block, vec4_instruction, inst, cfg) {
+ /* We only care about MOV_INDIRECT of a uniform */
+ if (inst->opcode != SHADER_OPCODE_MOV_INDIRECT ||
+ inst->src[0].file != UNIFORM)
+ continue;
- dst_reg temp = dst_reg(this, glsl_type::vec4_type);
+ int uniform_nr = inst->src[0].nr + inst->src[0].reg_offset;
- emit_pull_constant_load(block, inst, temp, inst->src[i],
- pull_constant_loc[uniform]);
+ assert(inst->src[0].swizzle == BRW_SWIZZLE_NOOP);
- inst->src[i].file = temp.file;
- inst->src[i].nr = temp.nr;
- inst->src[i].reg_offset = temp.reg_offset;
- inst->src[i].reladdr = NULL;
- }
- }
- } while (nested_reladdr);
+ emit_pull_constant_load(block, inst, inst->dst, inst->src[0],
+ pull_constant_loc[uniform_nr], inst->src[1]);
+ inst->remove(block);
+ }
/* Now there are no accesses of the UNIFORM file with a reladdr, so
* no need to track them as larger-than-vec4 objects. This will be
--
2.5.0.400.gff86faf
More information about the mesa-dev
mailing list