[Mesa-dev] [PATCH] nir: add lowering pass for glBitmap
Rob Clark
robdclark at gmail.com
Thu Apr 14 22:40:00 UTC 2016
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..
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
>>
>> _______________________________________________
>> mesa-dev mailing list
>> mesa-dev at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/mesa-dev
More information about the mesa-dev
mailing list