[Mesa-dev] [PATCH 5/7] i965/fs: Don't renumber UNIFORM registers.
Kenneth Graunke
kenneth at whitecape.org
Tue Mar 11 23:48:54 PDT 2014
Previously, remove_dead_constants() would renumber the UNIFORM registers
to be sequential starting from zero, and the resulting register number
would be used directly as an index into the params[] array.
This renumbering made it difficult to collect and save information about
pull constant locations, since setup_pull_constants() and
move_uniform_array_access_to_pull_constants() used different names.
This patch generalizes setup_pull_constants() to decide whether each
uniform register should be a pull constant, push constant, or neither
(because it's unused). Then, it stores mappings from UNIFORM register
numbers to params[] or pull_params[] indices in the push_constant_loc
and pull_constant_loc arrays. (We already did this for pull constants.)
Then, assign_curb_setup() just needs to consult the push_constant_loc
array to get the real index into the params[] array.
This effectively folds all the remove_dead_constants() functionality
into assign_constant_locations(), while being less irritable to work
with.
Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
src/mesa/drivers/dri/i965/brw_fs.cpp | 187 +++++++++++----------------
src/mesa/drivers/dri/i965/brw_fs.h | 13 +-
src/mesa/drivers/dri/i965/brw_fs_visitor.cpp | 3 +-
3 files changed, 85 insertions(+), 118 deletions(-)
diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 3c8237a..5e01e78 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -885,8 +885,8 @@ fs_visitor::import_uniforms(fs_visitor *v)
hash_table_call_foreach(v->variable_ht,
import_uniforms_callback,
variable_ht);
- this->params_remap = v->params_remap;
- this->nr_params_remap = v->nr_params_remap;
+ this->push_constant_loc = v->push_constant_loc;
+ this->uniforms = v->uniforms;
}
/* Our support for uniforms is piggy-backed on the struct
@@ -1397,11 +1397,8 @@ fs_visitor::assign_curb_setup()
{
if (dispatch_width == 8) {
c->prog_data.first_curbe_grf = c->nr_payload_regs;
- stage_prog_data->nr_params = uniforms;
} else {
c->prog_data.first_curbe_grf_16 = c->nr_payload_regs;
- /* Make sure we didn't try to sneak in an extra uniform */
- assert(uniforms == 0);
}
c->prog_data.curb_read_length = ALIGN(stage_prog_data->nr_params, 8) / 8;
@@ -1412,7 +1409,19 @@ fs_visitor::assign_curb_setup()
for (unsigned int i = 0; i < 3; i++) {
if (inst->src[i].file == UNIFORM) {
- int constant_nr = inst->src[i].reg + inst->src[i].reg_offset;
+ int uniform_nr = inst->src[i].reg + inst->src[i].reg_offset;
+ int constant_nr;
+ if (uniform_nr >= 0 && uniform_nr < (int) uniforms) {
+ constant_nr = push_constant_loc[uniform_nr];
+ } else {
+ /* Section 5.11 of the OpenGL 4.1 spec says:
+ * "Out-of-bounds reads return undefined values, which include
+ * values from other variables of the active program or zero."
+ * Just return the first push constant.
+ */
+ constant_nr = 0;
+ }
+
struct brw_reg brw_reg = brw_vec1_grf(c->nr_payload_regs +
constant_nr / 8,
constant_nr % 8);
@@ -1724,94 +1733,6 @@ fs_visitor::compact_virtual_grfs()
}
}
-bool
-fs_visitor::remove_dead_constants()
-{
- if (dispatch_width == 8) {
- this->params_remap = ralloc_array(mem_ctx, int, uniforms);
- this->nr_params_remap = uniforms;
-
- for (unsigned int i = 0; i < uniforms; i++)
- this->params_remap[i] = -1;
-
- /* Find which params are still in use. */
- foreach_list(node, &this->instructions) {
- fs_inst *inst = (fs_inst *)node;
-
- for (int i = 0; i < 3; i++) {
- int constant_nr = inst->src[i].reg + inst->src[i].reg_offset;
-
- if (inst->src[i].file != UNIFORM)
- continue;
-
- /* Section 5.11 of the OpenGL 4.3 spec says:
- *
- * "Out-of-bounds reads return undefined values, which include
- * values from other variables of the active program or zero."
- */
- if (constant_nr < 0 || constant_nr >= (int)uniforms) {
- constant_nr = 0;
- }
-
- /* For now, set this to non-negative. We'll give it the
- * actual new number in a moment, in order to keep the
- * register numbers nicely ordered.
- */
- this->params_remap[constant_nr] = 0;
- }
- }
-
- /* Figure out what the new numbers for the params will be. At some
- * point when we're doing uniform array access, we're going to want
- * to keep the distinction between .reg and .reg_offset, but for
- * now we don't care.
- */
- unsigned int new_nr_params = 0;
- for (unsigned int i = 0; i < uniforms; i++) {
- if (this->params_remap[i] != -1) {
- this->params_remap[i] = new_nr_params++;
- }
- }
-
- /* Update the list of params to be uploaded to match our new numbering. */
- for (unsigned int i = 0; i < uniforms; i++) {
- int remapped = this->params_remap[i];
-
- if (remapped == -1)
- continue;
-
- stage_prog_data->param[remapped] = stage_prog_data->param[i];
- }
-
- uniforms = new_nr_params;
- } else {
- /* This should have been generated in the SIMD8 pass already. */
- assert(this->params_remap);
- }
-
- /* Now do the renumbering of the shader to remove unused params. */
- foreach_list(node, &this->instructions) {
- fs_inst *inst = (fs_inst *)node;
-
- for (int i = 0; i < 3; i++) {
- int constant_nr = inst->src[i].reg + inst->src[i].reg_offset;
-
- if (inst->src[i].file != UNIFORM)
- continue;
-
- /* as above alias to 0 */
- if (constant_nr < 0 || constant_nr >= (int)this->nr_params_remap) {
- constant_nr = 0;
- }
- assert(this->params_remap[constant_nr] != -1);
- inst->src[i].reg = this->params_remap[constant_nr];
- inst->src[i].reg_offset = 0;
- }
- }
-
- return true;
-}
-
/*
* Implements array access of uniforms by inserting a
* PULL_CONSTANT_LOAD instruction.
@@ -1872,8 +1793,7 @@ fs_visitor::move_uniform_array_access_to_pull_constants()
}
/**
- * Choose accesses from the UNIFORM file to demote to using the pull
- * constant buffer.
+ * Assign UNIFORM file registers to either push constants or pull constants.
*
* We allow a fragment shader to have more than the specified minimum
* maximum number of fragment shader uniform components (64). If
@@ -1882,24 +1802,62 @@ fs_visitor::move_uniform_array_access_to_pull_constants()
* update the program to load them.
*/
void
-fs_visitor::setup_pull_constants()
+fs_visitor::assign_constant_locations()
{
- /* Only allow 16 registers (128 uniform components) as push constants. */
- unsigned int max_uniform_components = 16 * 8;
- if (uniforms <= max_uniform_components)
+ /* Only the first compile (SIMD8 mode) gets to decide on locations. */
+ if (dispatch_width != 8)
return;
- /* Just demote the end of the list. We could probably do better
+ /* Find which UNIFORM registers are still in use. */
+ bool is_live[uniforms];
+ for (unsigned int i = 0; i < uniforms; i++) {
+ is_live[i] = false;
+ }
+
+ foreach_list(node, &this->instructions) {
+ fs_inst *inst = (fs_inst *) node;
+
+ for (int i = 0; i < 3; i++) {
+ if (inst->src[i].file != UNIFORM)
+ continue;
+
+ int constant_nr = inst->src[i].reg + inst->src[i].reg_offset;
+ if (constant_nr >= 0 && constant_nr < (int) uniforms)
+ is_live[constant_nr] = true;
+ }
+ }
+
+ /* Only allow 16 registers (128 uniform components) as push constants.
+ *
+ * Just demote the end of the list. We could probably do better
* here, demoting things that are rarely used in the program first.
*/
- unsigned int pull_uniform_base = max_uniform_components;
+ unsigned int max_push_components = 16 * 8;
+ unsigned int num_push_constants = 0;
+ push_constant_loc = ralloc_array(mem_ctx, int, uniforms);
pull_constant_loc = ralloc_array(mem_ctx, int, uniforms);
+ for (unsigned int i = 0; i < uniforms; i++)
+ pull_constant_loc[i] = -1;
+
for (unsigned int i = 0; i < uniforms; i++) {
- if (i < pull_uniform_base) {
- pull_constant_loc[i] = -1;
+ if (!is_live[i] || pull_constant_loc[i] != -1) {
+ /* This UNIFORM register is either dead, or has already been demoted
+ * to a pull const. Mark it as no longer living in the param[] array.
+ */
+ push_constant_loc[i] = -1;
+ continue;
+ }
+
+ if (num_push_constants < max_push_components) {
+ /* Retain as a push constant. Record the location in the params[]
+ * array.
+ */
+ push_constant_loc[i] = num_push_constants++;
} else {
- pull_constant_loc[i] = -1;
+ /* Demote to a pull constant. */
+ push_constant_loc[i] = -1;
+
/* If our constant is already being uploaded for reladdr purposes,
* reuse it.
*/
@@ -1916,7 +1874,21 @@ fs_visitor::setup_pull_constants()
}
}
}
- uniforms = pull_uniform_base;
+
+ stage_prog_data->nr_params = num_push_constants;
+
+ /* Up until now, the param[] array has been indexed by reg + reg_offset
+ * of UNIFORM registers. Condense it to only contain the uniforms we
+ * chose to upload as push constants.
+ */
+ for (unsigned int i = 0; i < uniforms; i++) {
+ int remapped = push_constant_loc[i];
+
+ if (remapped == -1)
+ continue;
+
+ stage_prog_data->param[remapped] = stage_prog_data->param[i];
+ }
demote_pull_constants(false);
}
@@ -3408,8 +3380,7 @@ fs_visitor::run()
split_virtual_grfs();
move_uniform_array_access_to_pull_constants();
- remove_dead_constants();
- setup_pull_constants();
+ assign_constant_locations();
opt_drop_redundant_mov_to_flags();
diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h
index 2ef5a29..5733a49 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_fs.h
@@ -357,7 +357,7 @@ public:
void split_virtual_grfs();
void compact_virtual_grfs();
void move_uniform_array_access_to_pull_constants();
- void setup_pull_constants();
+ void assign_constant_locations();
void demote_pull_constants(bool reladdr_only);
void invalidate_live_intervals();
void calculate_live_intervals();
@@ -375,7 +375,6 @@ public:
bool compute_to_mrf();
bool dead_code_eliminate();
bool dead_code_eliminate_local();
- bool remove_dead_constants();
bool remove_duplicate_mrf_writes();
bool virtual_grf_interferes(int a, int b);
void schedule_instructions(instruction_scheduler_mode mode);
@@ -516,13 +515,11 @@ public:
*/
int *pull_constant_loc;
- /* This is the map from UNIFORM hw_reg + reg_offset as generated by
- * the visitor to the packed uniform number after
- * remove_dead_constants() that represents the actual uploaded
- * uniform index.
+ /**
+ * Array mapping UNIFORM register numbers to the push parameter index,
+ * or -1 if this uniform register isn't being uploaded as a push constant.
*/
- int *params_remap;
- int nr_params_remap;
+ int *push_constant_loc;
struct hash_table *variable_ht;
fs_reg frag_depth;
diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
index 404af30..7088502 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
@@ -2972,8 +2972,7 @@ fs_visitor::fs_visitor(struct brw_context *brw,
this->uniforms = 0;
this->pull_constant_loc = NULL;
- this->params_remap = NULL;
- this->nr_params_remap = 0;
+ this->push_constant_loc = NULL;
this->force_uncompressed_stack = 0;
--
1.9.0
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