On Fri, Mar 14, 2014 at 08:15:33PM +0200, Pohjolainen, Topi wrote:
> On Tue, Mar 11, 2014 at 11:48:54PM -0700, Kenneth Graunke wrote:
> > 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 <kenn...@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;
>
> This could be declared as constant. Otherwise I've read this over a few times
> and it looks just fine. Makes it simpler and consistent between push and pull.
>
> Reviewed-by: Topi Pohjolainen <topi.pohjolai...@intel.com>
>
> You might want to have a second opinion though.
Patches 6 and 7 are also
Reviewed-by: Topi Pohjolainen <topi.pohjolai...@intel.com>
>
> > + 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
> >
> > _______________________________________________
> > mesa-dev mailing list
> > mesa-dev@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/mesa-dev
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