On Sat, May 14, 2016 at 4:43 PM, Jason Ekstrand <ja...@jlekstrand.net> wrote:
> On Sat, May 14, 2016 at 12:23 PM, Rob Clark <robdcl...@gmail.com> wrote:
>>
>> On Thu, May 12, 2016 at 10:17 PM, Jason Ekstrand <ja...@jlekstrand.net>
>> wrote:
>> >
>> >
>> > On Mon, May 9, 2016 at 12:33 PM, Rob Clark <robdcl...@gmail.com> wrote:
>> >>
>> >> From: Rob Clark <robcl...@freedesktop.org>
>> >>
>> >> Signed-off-by: Rob Clark <robcl...@freedesktop.org>
>> >> Reviewed-by: Connor Abbott <cwabbo...@gmail.com>
>> >> ---
>> >> src/compiler/Makefile.sources | 1 +
>> >> src/compiler/nir/nir.h | 11 +
>> >> src/compiler/nir/nir_lower_wpos_ytransform.c | 310
>> >> +++++++++++++++++++++++++++
>> >> 3 files changed, 322 insertions(+)
>> >> create mode 100644 src/compiler/nir/nir_lower_wpos_ytransform.c
>> >>
>> >> diff --git a/src/compiler/Makefile.sources
>> >> b/src/compiler/Makefile.sources
>> >> index 2a52319..b542a1a 100644
>> >> --- a/src/compiler/Makefile.sources
>> >> +++ b/src/compiler/Makefile.sources
>> >> @@ -208,6 +208,7 @@ NIR_FILES = \
>> >> nir/nir_lower_vars_to_ssa.c \
>> >> nir/nir_lower_var_copies.c \
>> >> nir/nir_lower_vec_to_movs.c \
>> >> + nir/nir_lower_wpos_ytransform.c \
>> >> nir/nir_metadata.c \
>> >> nir/nir_move_vec_src_uses_to_dest.c \
>> >> nir/nir_normalize_cubemap_coords.c \
>> >> diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
>> >> index 8a616d4..474ba63 100644
>> >> --- a/src/compiler/nir/nir.h
>> >> +++ b/src/compiler/nir/nir.h
>> >> @@ -2374,6 +2374,17 @@ void nir_lower_two_sided_color(nir_shader
>> >> *shader);
>> >>
>> >> void nir_lower_clamp_color_outputs(nir_shader *shader);
>> >>
>> >> +typedef struct nir_lower_wpos_ytransform_options {
>> >> + int state_tokens[5];
>> >> + bool fs_coord_origin_upper_left :1;
>> >> + bool fs_coord_origin_lower_left :1;
>> >> + bool fs_coord_pixel_center_integer :1;
>> >> + bool fs_coord_pixel_center_half_integer :1;
>> >
>> >
>> > Drive-by commentary: Why are we using two booleans for one boolean here?
>> > All hardware should be either lower-left or upper-left and I'm going to
>> > hazard that the other two are mutually exclusive as well. The pass
>> > certainly seems to assume so.
>>
>> mostly just because gallium splits it out into two caps, and this
>> matches the logic in the equiv tgsi lowering pass more closely..
>>
>> The way it is currently would, I think, work if there was some hw that
>> supported both cases (which is, I assume, why the gallium part of it
>> works the way it does)
>
>
> Yeah, I guess I could see that. In that case, I suppose you could just not
> run the pass? I guess you could have a case where HW supports both
> gl_FragCoords modes but only one pixel-center mode. Whatever. I guess I'm
> ok with 4 bools if it's useful.
>
Yeah, not entirely sure why you'd run the pass if hw supported both
cases.. at this point, the strongest argument for keeping it as-is is
probably just to keep the logic similar to equiv tgsi lowering pass.
Maybe someone with a longer history on the gallium/tgsi side of things
will pipe up.
BR,
-R
>>
>>
>> BR,
>> -R
>>
>> > Let's just make it two booleans. If we come across hardware that puts
>> > the
>> > pixel center at 0.75, 0.25 then we can make fs_coord_pixel_center an
>> > enum.
>> > --Jason
>> >
>> >>
>> >> +} nir_lower_wpos_ytransform_options;
>> >> +
>> >> +bool nir_lower_wpos_ytransform(nir_shader *shader,
>> >> + const nir_lower_wpos_ytransform_options
>> >> *options);
>> >> +
>> >> void nir_lower_atomics(nir_shader *shader,
>> >> const struct gl_shader_program
>> >> *shader_program);
>> >> void nir_lower_to_source_mods(nir_shader *shader);
>> >> diff --git a/src/compiler/nir/nir_lower_wpos_ytransform.c
>> >> b/src/compiler/nir/nir_lower_wpos_ytransform.c
>> >> new file mode 100644
>> >> index 0000000..1d53530
>> >> --- /dev/null
>> >> +++ b/src/compiler/nir/nir_lower_wpos_ytransform.c
>> >> @@ -0,0 +1,310 @@
>> >> +/*
>> >> + * Copyright © 2015 Red Hat
>> >> + *
>> >> + * Permission is hereby granted, free of charge, to any person
>> >> obtaining
>> >> a
>> >> + * copy of this software and associated documentation files (the
>> >> "Software"),
>> >> + * to deal in the Software without restriction, including without
>> >> limitation
>> >> + * the rights to use, copy, modify, merge, publish, distribute,
>> >> sublicense,
>> >> + * and/or sell copies of the Software, and to permit persons to whom
>> >> the
>> >> + * Software is furnished to do so, subject to the following
>> >> conditions:
>> >> + *
>> >> + * The above copyright notice and this permission notice (including
>> >> the
>> >> next
>> >> + * paragraph) shall be included in all copies or substantial portions
>> >> of
>> >> the
>> >> + * Software.
>> >> + *
>> >> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
>> >> EXPRESS OR
>> >> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
>> >> MERCHANTABILITY,
>> >> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
>> >> SHALL
>> >> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
>> >> OR
>> >> OTHER
>> >> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
>> >> ARISING FROM,
>> >> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
>> >> DEALINGS
>> >> IN THE
>> >> + * SOFTWARE.
>> >> + */
>> >> +
>> >> +#include "nir.h"
>> >> +#include "nir_builder.h"
>> >> +
>> >> +/* Lower gl_FragCoord (and fddy) to account for driver's requested
>> >> coordinate-
>> >> + * origin and pixel-center vs. shader. If transformation is required,
>> >> a
>> >> + * gl_FbWposYTransform uniform is inserted (with the specified
>> >> state-slots)
>> >> + * and additional instructions are inserted to transform gl_FragCoord
>> >> (and
>> >> + * fddy src arg).
>> >> + *
>> >> + * This is based on the logic in emit_wpos()/emit_wpos_adjustment() in
>> >> TGSI
>> >> + * compiler.
>> >> + *
>> >> + * Run before nir_lower_io.
>> >> + */
>> >> +
>> >> +typedef struct {
>> >> + const nir_lower_wpos_ytransform_options *options;
>> >> + nir_shader *shader;
>> >> + nir_builder b;
>> >> + nir_variable *transform;
>> >> +} lower_wpos_ytransform_state;
>> >> +
>> >> +static nir_ssa_def *
>> >> +get_transform(lower_wpos_ytransform_state *state)
>> >> +{
>> >> + if (state->transform == NULL) {
>> >> + /* NOTE: name must be prefixed w/ "gl_" to trigger slot based
>> >> + * special handling in uniform setup:
>> >> + */
>> >> + nir_variable *var = nir_variable_create(state->shader,
>> >> + nir_var_uniform,
>> >> + glsl_vec4_type(),
>> >> + "gl_FbWposYTransform");
>> >> +
>> >> + var->num_state_slots = 1;
>> >> + var->state_slots = ralloc_array(var, nir_state_slot, 1);
>> >> + memcpy(var->state_slots[0].tokens, state->options->state_tokens,
>> >> + sizeof(var->state_slots[0].tokens));
>> >> +
>> >> + state->transform = var;
>> >> + }
>> >> + return nir_load_var(&state->b, state->transform);
>> >> +}
>> >> +
>> >> +/* NIR equiv of TGSI CMP instruction: */
>> >> +static nir_ssa_def *
>> >> +nir_cmp(nir_builder *b, nir_ssa_def *src0, nir_ssa_def *src1,
>> >> nir_ssa_def
>> >> *src2)
>> >> +{
>> >> + return nir_bcsel(b, nir_flt(b, src0, nir_imm_float(b, 0.0)), src1,
>> >> src2);
>> >> +}
>> >> +
>> >> +/* see emit_wpos_adjustment() in st_mesa_to_tgsi.c */
>> >> +static void
>> >> +emit_wpos_adjustment(lower_wpos_ytransform_state *state,
>> >> + nir_intrinsic_instr *intr,
>> >> + bool invert, float adjX, float adjY[2])
>> >> +{
>> >> + nir_builder *b = &state->b;
>> >> + nir_variable *fragcoord = intr->variables[0]->var;
>> >> + nir_ssa_def *wpostrans, *wpos_temp, *wpos_temp_y, *wpos_input;
>> >> +
>> >> + assert(intr->dest.is_ssa);
>> >> +
>> >> + b->cursor = nir_before_instr(&intr->instr);
>> >> +
>> >> + wpostrans = get_transform(state);
>> >> + wpos_input = nir_load_var(b, fragcoord);
>> >> +
>> >> + /* First, apply the coordinate shift: */
>> >> + if (adjX || adjY[0] || adjY[1]) {
>> >> + if (adjY[0] != adjY[1]) {
>> >> + /* Adjust the y coordinate by adjY[1] or adjY[0] respectively
>> >> + * depending on whether inversion is actually going to be
>> >> applied
>> >> + * or not, which is determined by testing against the
>> >> inversion
>> >> + * state variable used below, which will be either +1 or -1.
>> >> + */
>> >> + nir_ssa_def *adj_temp;
>> >> +
>> >> + adj_temp = nir_cmp(b,
>> >> + nir_channel(b, wpostrans, invert ? 2 : 0),
>> >> + nir_imm_vec4(b, adjX, adjY[0], 0.0f,
>> >> 0.0f),
>> >> + nir_imm_vec4(b, adjX, adjY[1], 0.0f,
>> >> 0.0f));
>> >> +
>> >> + wpos_temp = nir_fadd(b, wpos_input, adj_temp);
>> >> + } else {
>> >> + wpos_temp = nir_fadd(b,
>> >> + wpos_input,
>> >> + nir_imm_vec4(b, adjX, adjY[0], 0.0f,
>> >> 0.0f));
>> >> + }
>> >> + wpos_input = wpos_temp;
>> >> + } else {
>> >> + /* MOV wpos_temp, input[wpos]
>> >> + */
>> >> + wpos_temp = wpos_input;
>> >> + }
>> >> +
>> >> + /* Now the conditional y flip: STATE_FB_WPOS_Y_TRANSFORM.xy/zw will
>> >> be
>> >> + * inversion/identity, or the other way around if we're drawing to
>> >> an
>> >> FBO.
>> >> + */
>> >> + if (invert) {
>> >> + /* MAD wpos_temp.y, wpos_input, wpostrans.xxxx, wpostrans.yyyy
>> >> + */
>> >> + wpos_temp_y = nir_ffma(b,
>> >> + nir_channel(b, wpos_temp, 1),
>> >> + nir_channel(b, wpostrans, 0),
>> >> + nir_channel(b, wpostrans, 1));
>> >> + } else {
>> >> + /* MAD wpos_temp.y, wpos_input, wpostrans.zzzz, wpostrans.wwww
>> >> + */
>> >> + wpos_temp_y = nir_ffma(b,
>> >> + nir_channel(b, wpos_temp, 1),
>> >> + nir_channel(b, wpostrans, 2),
>> >> + nir_channel(b, wpostrans, 3));
>> >> + }
>> >> +
>> >> + wpos_temp = nir_vec4(b,
>> >> + nir_channel(b, wpos_temp, 0),
>> >> + wpos_temp_y,
>> >> + nir_channel(b, wpos_temp, 2),
>> >> + nir_channel(b, wpos_temp, 3));
>> >> +
>> >> + nir_ssa_def_rewrite_uses(&intr->dest.ssa,
>> >> nir_src_for_ssa(wpos_temp));
>> >> +}
>> >> +
>> >> +static void
>> >> +lower_fragcoord(lower_wpos_ytransform_state *state,
>> >> nir_intrinsic_instr
>> >> *intr)
>> >> +{
>> >> + const nir_lower_wpos_ytransform_options *options = state->options;
>> >> + nir_variable *fragcoord = intr->variables[0]->var;
>> >> + float adjX = 0.0f;
>> >> + float adjY[2] = { 0.0f, 0.0f };
>> >> + bool invert = false;
>> >> +
>> >> + /* Based on logic in emit_wpos():
>> >> + *
>> >> + * Query the pixel center conventions supported by the pipe driver
>> >> and
>> >> set
>> >> + * adjX, adjY to help out if it cannot handle the requested one
>> >> internally.
>> >> + *
>> >> + * The bias of the y-coordinate depends on whether y-inversion
>> >> takes
>> >> place
>> >> + * (adjY[1]) or not (adjY[0]), which is in turn dependent on
>> >> whether
>> >> we are
>> >> + * drawing to an FBO (causes additional inversion), and whether the
>> >> the pipe
>> >> + * driver origin and the requested origin differ (the latter
>> >> condition
>> >> is
>> >> + * stored in the 'invert' variable).
>> >> + *
>> >> + * For height = 100 (i = integer, h = half-integer, l = lower, u =
>> >> upper):
>> >> + *
>> >> + * center shift only:
>> >> + * i -> h: +0.5
>> >> + * h -> i: -0.5
>> >> + *
>> >> + * inversion only:
>> >> + * l,i -> u,i: ( 0.0 + 1.0) * -1 + 100 = 99
>> >> + * l,h -> u,h: ( 0.5 + 0.0) * -1 + 100 = 99.5
>> >> + * u,i -> l,i: (99.0 + 1.0) * -1 + 100 = 0
>> >> + * u,h -> l,h: (99.5 + 0.0) * -1 + 100 = 0.5
>> >> + *
>> >> + * inversion and center shift:
>> >> + * l,i -> u,h: ( 0.0 + 0.5) * -1 + 100 = 99.5
>> >> + * l,h -> u,i: ( 0.5 + 0.5) * -1 + 100 = 99
>> >> + * u,i -> l,h: (99.0 + 0.5) * -1 + 100 = 0.5
>> >> + * u,h -> l,i: (99.5 + 0.5) * -1 + 100 = 0
>> >> + */
>> >> +
>> >> + if (fragcoord->data.origin_upper_left) {
>> >> + /* Fragment shader wants origin in upper-left */
>> >> + if (options->fs_coord_origin_upper_left) {
>> >> + /* the driver supports upper-left origin */
>> >> + } else if (options->fs_coord_origin_lower_left) {
>> >> + /* the driver supports lower-left origin, need to invert Y */
>> >> + invert = true;
>> >> + } else {
>> >> + unreachable("invalid options");
>> >> + }
>> >> + } else {
>> >> + /* Fragment shader wants origin in lower-left */
>> >> + if (options->fs_coord_origin_lower_left) {
>> >> + /* the driver supports lower-left origin */
>> >> + } else if (options->fs_coord_origin_upper_left) {
>> >> + /* the driver supports upper-left origin, need to invert Y */
>> >> + invert = true;
>> >> + } else {
>> >> + unreachable("invalid options");
>> >> + }
>> >> + }
>> >> +
>> >> + if (fragcoord->data.pixel_center_integer) {
>> >> + /* Fragment shader wants pixel center integer */
>> >> + if (options->fs_coord_pixel_center_integer) {
>> >> + /* the driver supports pixel center integer */
>> >> + adjY[1] = 1.0f;
>> >> + } else if (options->fs_coord_pixel_center_half_integer) {
>> >> + /* the driver supports pixel center half integer, need to
>> >> bias
>> >> X,Y */
>> >> + adjX = -0.5f;
>> >> + adjY[0] = -0.5f;
>> >> + adjY[1] = 0.5f;
>> >> + } else {
>> >> + unreachable("invalid options");
>> >> + }
>> >> + } else {
>> >> + /* Fragment shader wants pixel center half integer */
>> >> + if (options->fs_coord_pixel_center_half_integer) {
>> >> + /* the driver supports pixel center half integer */
>> >> + } else if (options->fs_coord_pixel_center_integer) {
>> >> + /* the driver supports pixel center integer, need to bias X,Y
>> >> */
>> >> + adjX = adjY[0] = adjY[1] = 0.5f;
>> >> + } else {
>> >> + unreachable("invalid options");
>> >> + }
>> >> + }
>> >> +
>> >> + emit_wpos_adjustment(state, intr, invert, adjX, adjY);
>> >> +}
>> >> +
>> >> +/* turns 'fddy(p)' into 'fddy(fmul(p, transform.x))' */
>> >> +static void
>> >> +lower_fddy(lower_wpos_ytransform_state *state, nir_alu_instr *fddy)
>> >> +{
>> >> + nir_builder *b = &state->b;
>> >> + nir_ssa_def *p, *pt, *trans;
>> >> +
>> >> + b->cursor = nir_before_instr(&fddy->instr);
>> >> +
>> >> + p = nir_ssa_for_alu_src(b, fddy, 0);
>> >> + trans = get_transform(state);
>> >> + pt = nir_fmul(b, p, nir_channel(b, trans, 0));
>> >> +
>> >> + nir_instr_rewrite_src(&fddy->instr,
>> >> + &fddy->src[0].src,
>> >> + nir_src_for_ssa(pt));
>> >> +}
>> >> +
>> >> +static bool
>> >> +lower_wpos_ytransform_block(lower_wpos_ytransform_state *state,
>> >> nir_block
>> >> *block)
>> >> +{
>> >> + nir_foreach_instr_safe(instr, block) {
>> >> + if (instr->type == nir_instr_type_intrinsic) {
>> >> + nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
>> >> + if (intr->intrinsic == nir_intrinsic_load_var) {
>> >> + nir_deref_var *dvar = intr->variables[0];
>> >> + nir_variable *var = dvar->var;
>> >> +
>> >> + if (strcmp(var->name, "gl_FragCoord") == 0) {
>> >> + /* gl_FragCoord should not have array/struct deref's:
>> >> */
>> >> + assert(dvar->deref.child == NULL);
>> >> + lower_fragcoord(state, intr);
>> >> + }
>> >> + }
>> >> + } else if (instr->type == nir_instr_type_alu) {
>> >> + nir_alu_instr *alu = nir_instr_as_alu(instr);
>> >> + if (alu->op == nir_op_fddy)
>> >> + lower_fddy(state, alu);
>> >> + }
>> >> + }
>> >> +
>> >> + return true;
>> >> +}
>> >> +
>> >> +static void
>> >> +lower_wpos_ytransform_impl(lower_wpos_ytransform_state *state,
>> >> nir_function_impl *impl)
>> >> +{
>> >> + nir_builder_init(&state->b, impl);
>> >> +
>> >> + nir_foreach_block(block, impl) {
>> >> + lower_wpos_ytransform_block(state, block);
>> >> + }
>> >> + nir_metadata_preserve(impl, nir_metadata_block_index |
>> >> + nir_metadata_dominance);
>> >> +}
>> >> +
>> >> +bool
>> >> +nir_lower_wpos_ytransform(nir_shader *shader,
>> >> + const nir_lower_wpos_ytransform_options
>> >> *options)
>> >> +{
>> >> + lower_wpos_ytransform_state state = {
>> >> + .options = options,
>> >> + .shader = shader,
>> >> + };
>> >> +
>> >> + assert(shader->stage == MESA_SHADER_FRAGMENT);
>> >> +
>> >> + nir_foreach_function(function, shader) {
>> >> + if (function->impl)
>> >> + lower_wpos_ytransform_impl(&state, function->impl);
>> >> + }
>> >> +
>> >> + return state.transform != NULL;
>> >> +}
>> >> --
>> >> 2.5.5
>> >>
>> >
>
>
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