[Mesa-dev] [PATCH] nir: add lowering pass for glBitmap
Rob Clark
robdclark at gmail.com
Thu Apr 14 22:43:15 UTC 2016
On Thu, Apr 14, 2016 at 6:40 PM, Rob Clark <robdclark at gmail.com> wrote:
> On Thu, Apr 14, 2016 at 6:33 PM, Connor Abbott <cwabbott0 at gmail.com> wrote:
>> On Thu, Apr 14, 2016 at 6:10 PM, Rob Clark <robdclark at gmail.com> wrote:
>>> From: Rob Clark <robclark at freedesktop.org>
>>>
>>> Signed-off-by: Rob Clark <robclark at freedesktop.org>
>>> Reviewed-by: Connor Abbott <cwabbott0 at gmail.com>
>>> ---
>>> src/compiler/Makefile.sources | 1 +
>>> src/compiler/nir/nir.h | 7 ++
>>> src/compiler/nir/nir_lower_bitmap.c | 167 ++++++++++++++++++++++++++++++++++++
>>> 3 files changed, 175 insertions(+)
>>> create mode 100644 src/compiler/nir/nir_lower_bitmap.c
>>>
>>> diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources
>>> index 290ed35..8d8eca2 100644
>>> --- a/src/compiler/Makefile.sources
>>> +++ b/src/compiler/Makefile.sources
>>> @@ -186,6 +186,7 @@ NIR_FILES = \
>>> nir/nir_liveness.c \
>>> nir/nir_lower_alu_to_scalar.c \
>>> nir/nir_lower_atomics.c \
>>> + nir/nir_lower_bitmap.c \
>>> nir/nir_lower_clip.c \
>>> nir/nir_lower_double_packing.c \
>>> nir/nir_lower_drawpixels.c \
>>> diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
>>> index bdc9e8b..c334702 100644
>>> --- a/src/compiler/nir/nir.h
>>> +++ b/src/compiler/nir/nir.h
>>> @@ -2301,6 +2301,13 @@ typedef struct nir_lower_drawpixels_options {
>>> void nir_lower_drawpixels(nir_shader *shader,
>>> const nir_lower_drawpixels_options *options);
>>>
>>> +typedef struct nir_lower_bitmap_options {
>>> + unsigned sampler;
>>> + bool swizzle_xxxx;
>>> +} nir_lower_bitmap_options;
>>> +
>>> +void nir_lower_bitmap(nir_shader *shader, const nir_lower_bitmap_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_bitmap.c b/src/compiler/nir/nir_lower_bitmap.c
>>> new file mode 100644
>>> index 0000000..fdca80c
>>> --- /dev/null
>>> +++ b/src/compiler/nir/nir_lower_bitmap.c
>>> @@ -0,0 +1,167 @@
>>> +/*
>>> + * 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 glBitmap().
>>> + *
>>> + * This is based on the logic in st_get_bitmap_shader() in TGSI compiler.
>>> + * From st_cb_bitmap.c:
>>> + *
>>> + * glBitmaps are drawn as textured quads. The user's bitmap pattern
>>> + * is stored in a texture image. An alpha8 texture format is used.
>>> + * The fragment shader samples a bit (texel) from the texture, then
>>> + * discards the fragment if the bit is off.
>>> + *
>>> + * Note that we actually store the inverse image of the bitmap to
>>> + * simplify the fragment program. An "on" bit gets stored as texel=0x0
>>> + * and an "off" bit is stored as texel=0xff. Then we kill the
>>> + * fragment if the negated texel value is less than zero.
>>> + *
>>> + * Note that the texture format will be, according to what driver supports,
>>> + * in order of preference (with swizzle):
>>> + *
>>> + * I8_UNORM - .xxxx
>>> + * A8_UNORM - .000x
>>> + * L8_UNORM - .xxx1
>>> + *
>>> + * If L8_UNORM, options->swizzle_xxxx is true. Otherwise we can just use
>>> + * the .w comp.
>>> + *
>>> + * Run before nir_lower_io.
>>> + */
>>> +
>>> +typedef struct {
>>> + const nir_lower_bitmap_options *options;
>>> + nir_shader *shader;
>>> + nir_builder b;
>>> + nir_variable *texcoord;
>>> +} lower_bitmap_state;
>>> +
>>> +static nir_ssa_def *
>>> +get_texcoord(lower_bitmap_state *state)
>>> +{
>>> + if (state->texcoord == NULL) {
>>> + nir_variable *texcoord = NULL;
>>> +
>>> + /* find gl_TexCoord, if it exists: */
>>> + nir_foreach_variable(var, &state->shader->inputs) {
>>> + if (var->data.location == VARYING_SLOT_TEX0) {
>>> + texcoord = var;
>>> + break;
>>> + }
>>> + }
>>> +
>>> + /* otherwise create it: */
>>> + if (texcoord == NULL) {
>>> + texcoord = nir_variable_create(state->shader,
>>> + nir_var_shader_in,
>>> + glsl_vec4_type(),
>>> + "gl_TexCoord");
>>> + texcoord->data.location = VARYING_SLOT_TEX0;
>>> + }
>>> +
>>> + state->texcoord = texcoord;
>>> + }
>>> + return nir_load_var(&state->b, state->texcoord);
>>> +}
>>> +
>>> +static void
>>> +lower_bitmap(lower_bitmap_state *state, nir_instr *instr)
>>> +{
>>> + nir_builder *b = &state->b;
>>> + nir_ssa_def *texcoord;
>>> + nir_tex_instr *tex;
>>> + nir_ssa_def *cond;
>>> + nir_intrinsic_instr *discard;
>>> +
>>> + b->cursor = nir_before_instr(instr);
>>> +
>>> + texcoord = get_texcoord(state);
>>> +
>>> + tex = nir_tex_instr_create(state->shader, 1);
>>> + tex->op = nir_texop_tex;
>>> + tex->sampler_dim = GLSL_SAMPLER_DIM_2D;
>>> + tex->coord_components = 2;
>>> + tex->sampler_index = state->options->sampler;
>>> + tex->texture_index = state->options->sampler;
>>> + tex->dest_type = nir_type_float;
>>> + tex->src[0].src = nir_src_for_ssa(texcoord);
>>> +
>>> + nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32, NULL);
>>> + nir_builder_instr_insert(b, &tex->instr);
>>> +
>>> + /* kill if tex != 0.0.. take .x or .w channel according to format: */
>>> + cond = nir_f2b(b, nir_channel(b, &tex->dest.ssa,
>>> + state->options->swizzle_xxxx ? 0 : 3));
>>> +
>>> + discard = nir_intrinsic_instr_create(state->shader,
>>> + nir_intrinsic_discard_if);
>>> + discard->src[0] = nir_src_for_ssa(cond);
>>> + nir_builder_instr_insert(b, &discard->instr);
>>> +}
>>> +
>>> +static bool
>>> +lower_bitmap_block(nir_block *block, void *_state)
>>> +{
>>> + lower_bitmap_state *state = _state;
>>> +
>>> + /* TODO is there a better way to prepend instructions to
>>> + * the shader? If, hypothetically, there were more than
>>> + * one function, this probably wouldn't be the right way
>>> + */
>>
>> So this change happened after these patches were written, but there's
>> now nir_shader_get_entrypoint() so you should probably use that. Also,
>> you can use nir_start_block() to get the first block in the impl
>> rather than needing a separate function (and it won't conflict with my
>> rewrite series!).
>
> actually I did change it to use that (and also in the lower_edgeflags
> pass too).. but somehow completely messed up the squash/rebase and/or
> sent the wrong patch..
>
> give me a minute to sort that out and I'll resend..
ok, looks like I just had the wrong commit-id for git-format-patch for
this and the lower_edgeflags patch.. sorry for the noise, let me
resend these two
> BR,
> -R
>
>>> + nir_foreach_instr_safe(block, instr) {
>>> + lower_bitmap(state, instr);
>>> + break;
>>> + }
>>> +
>>> + return false;
>>> +}
>>> +
>>> +static void
>>> +lower_bitmap_impl(lower_bitmap_state *state, nir_function_impl *impl)
>>> +{
>>> + nir_builder_init(&state->b, impl);
>>> +
>>> + nir_foreach_block(impl, lower_bitmap_block, state);
>>> + nir_metadata_preserve(impl, nir_metadata_block_index |
>>> + nir_metadata_dominance);
>>> +}
>>> +
>>> +void
>>> +nir_lower_bitmap(nir_shader *shader,
>>> + const nir_lower_bitmap_options *options)
>>> +{
>>> + lower_bitmap_state state = {
>>> + .options = options,
>>> + .shader = shader,
>>> + };
>>> +
>>> + assert(shader->stage == MESA_SHADER_FRAGMENT);
>>> +
>>> + nir_foreach_function(shader, function) {
>>> + if (function->impl)
>>> + lower_bitmap_impl(&state, function->impl);
>>> + }
>>> +}
>>> --
>>> 2.5.5
>>>
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