[Mesa-dev] [PATCH 08/12] nir: Add a simple nir_lower_wpos_center() pass for Vulkan drivers.
nir_lower_wpos_ytransform() is great for OpenGL, which allows
applications to choose whether their coordinate system's origin is
upper left/lower left, and whether the pixel center should be on
integer/half-integer boundaries.
Vulkan, however, has much simpler requirements: the pixel center
is always half-integer, and the origin is always upper left. No
coordinate transform is needed - we just need to add <0.5, 0.5>.
This means that we can avoid using (and setting up) a uniform.
I thought about adding more options to nir_lower_wpos_ytransform(),
but making a new pass that never even touched uniforms seemed simpler.
Signed-off-by: Kenneth Graunke
---
src/compiler/Makefile.sources| 1 +
src/compiler/nir/nir.h | 1 +
src/compiler/nir/nir_lower_wpos_center.c | 107 +++
3 files changed, 109 insertions(+)
create mode 100644 src/compiler/nir/nir_lower_wpos_center.c
diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources
index 97f9eb4..b8f2b49 100644
--- a/src/compiler/Makefile.sources
+++ b/src/compiler/Makefile.sources
@@ -212,6 +212,7 @@ 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_center.c \
nir/nir_lower_wpos_ytransform.c \
nir/nir_metadata.c \
nir/nir_move_vec_src_uses_to_dest.c \
diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index a21a7bd..78913d3 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -2407,6 +2407,7 @@ typedef struct nir_lower_wpos_ytransform_options {
bool nir_lower_wpos_ytransform(nir_shader *shader,
const nir_lower_wpos_ytransform_options
*options);
+bool nir_lower_wpos_center(nir_shader *shader);
typedef struct nir_lower_drawpixels_options {
int texcoord_state_tokens[5];
diff --git a/src/compiler/nir/nir_lower_wpos_center.c
b/src/compiler/nir/nir_lower_wpos_center.c
new file mode 100644
index 000..d66109d
--- /dev/null
+++ b/src/compiler/nir/nir_lower_wpos_center.c
@@ -0,0 +1,107 @@
+/*
+ * Copyright © 2015 Red Hat
+ * Copyright © 2016 Intel Corporation
+ *
+ * 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"
+#include "program/prog_instruction.h"
+
+/**
+ * This pass adds <0.5, 0.5> to all uses of gl_FragCoord.
+ *
+ * Run before nir_lower_io().
+ *
+ * For a more full featured pass, consider using nir_lower_wpos_ytransform(),
+ * which can handle pixel center integer / half integer, and origin lower
+ * left / upper left transformations.
+ *
+ * This simple pass is primarily intended for use by Vulkan drivers on
+ * hardware which provides an integer pixel center. Vulkan mandates that
+ * the pixel center must be half-integer, and also that the coordinate
+ * system's origin must be upper left. This means that there's no need
+ * for a uniform - we can always just add a constant.
+ */
+
+static void
+add_half_to_fragcoord(nir_builder *b, nir_intrinsic_instr *intr)
+{
+ nir_ssa_def *wpos = &intr->dest.ssa;
+
+ assert(intr->dest.is_ssa);
+
+ b->cursor = nir_after_instr(&intr->instr);
+
+ wpos = nir_fadd(b, wpos, nir_imm_vec4(b, 0.5f, 0.5f, 0.0f, 0.0f));
+
+ nir_ssa_def_rewrite_uses_after(&intr->dest.ssa, nir_src_for_ssa(wpos),
+ &intr->instr);
+}
+
+static bool
+lower_wpos_center_block(nir_builder *b, nir_block *block)
+{
+ bool progress = false;
+
+ 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 (var->data.mode == nir_var_shader_in &&
+var->d
Re: [Mesa-dev] [PATCH 08/12] nir: Add a simple nir_lower_wpos_center() pass for Vulkan drivers.
On Wed, May 18, 2016 at 3:00 PM, Kenneth Graunke wrote:
> nir_lower_wpos_ytransform() is great for OpenGL, which allows
> applications to choose whether their coordinate system's origin is
> upper left/lower left, and whether the pixel center should be on
> integer/half-integer boundaries.
>
> Vulkan, however, has much simpler requirements: the pixel center
> is always half-integer, and the origin is always upper left. No
> coordinate transform is needed - we just need to add <0.5, 0.5>.
> This means that we can avoid using (and setting up) a uniform.
>
> I thought about adding more options to nir_lower_wpos_ytransform(),
> but making a new pass that never even touched uniforms seemed simpler.
>
> Signed-off-by: Kenneth Graunke
> ---
> src/compiler/Makefile.sources| 1 +
> src/compiler/nir/nir.h | 1 +
> src/compiler/nir/nir_lower_wpos_center.c | 107
> +++
> 3 files changed, 109 insertions(+)
> create mode 100644 src/compiler/nir/nir_lower_wpos_center.c
>
> diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources
> index 97f9eb4..b8f2b49 100644
> --- a/src/compiler/Makefile.sources
> +++ b/src/compiler/Makefile.sources
> @@ -212,6 +212,7 @@ 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_center.c \
> nir/nir_lower_wpos_ytransform.c \
> nir/nir_metadata.c \
> nir/nir_move_vec_src_uses_to_dest.c \
> diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
> index a21a7bd..78913d3 100644
> --- a/src/compiler/nir/nir.h
> +++ b/src/compiler/nir/nir.h
> @@ -2407,6 +2407,7 @@ typedef struct nir_lower_wpos_ytransform_options {
>
> bool nir_lower_wpos_ytransform(nir_shader *shader,
> const nir_lower_wpos_ytransform_options
> *options);
> +bool nir_lower_wpos_center(nir_shader *shader);
>
> typedef struct nir_lower_drawpixels_options {
> int texcoord_state_tokens[5];
> diff --git a/src/compiler/nir/nir_lower_wpos_center.c
> b/src/compiler/nir/nir_lower_wpos_center.c
> new file mode 100644
> index 000..d66109d
> --- /dev/null
> +++ b/src/compiler/nir/nir_lower_wpos_center.c
> @@ -0,0 +1,107 @@
> +/*
> + * Copyright © 2015 Red Hat
> + * Copyright © 2016 Intel Corporation
> + *
> + * 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"
> +#include "program/prog_instruction.h"
> +
> +/**
> + * This pass adds <0.5, 0.5> to all uses of gl_FragCoord.
> + *
> + * Run before nir_lower_io().
> + *
> + * For a more full featured pass, consider using nir_lower_wpos_ytransform(),
> + * which can handle pixel center integer / half integer, and origin lower
> + * left / upper left transformations.
> + *
> + * This simple pass is primarily intended for use by Vulkan drivers on
> + * hardware which provides an integer pixel center. Vulkan mandates that
> + * the pixel center must be half-integer, and also that the coordinate
> + * system's origin must be upper left. This means that there's no need
> + * for a uniform - we can always just add a constant.
> + */
> +
> +static void
> +add_half_to_fragcoord(nir_builder *b, nir_intrinsic_instr *intr)
> +{
> + nir_ssa_def *wpos = &intr->dest.ssa;
> +
> + assert(intr->dest.is_ssa);
> +
> + b->cursor = nir_after_instr(&intr->instr);
> +
> + wpos = nir_fadd(b, wpos, nir_imm_vec4(b, 0.5f, 0.5f, 0.0f, 0.0f));
> +
> + nir_ssa_def_rewrite_uses_after(&intr->dest.ssa, nir_src_for_ssa(wpos),
> + &intr->instr);
> +}
> +
> +static bool
> +lower_wpos_center_block(nir_builder *b, nir_block *block)
> +{
> + bool progress = false;
> +
> + nir_foreach_instr_safe(instr, block) {
Does this need to be _safe? If it does, why (for my own education)?
__
Re: [Mesa-dev] [PATCH 08/12] nir: Add a simple nir_lower_wpos_center() pass for Vulkan drivers.
On Thursday, May 19, 2016 1:21:16 PM PDT Matt Turner wrote:
> On Wed, May 18, 2016 at 3:00 PM, Kenneth Graunke
wrote:
> > nir_lower_wpos_ytransform() is great for OpenGL, which allows
> > applications to choose whether their coordinate system's origin is
> > upper left/lower left, and whether the pixel center should be on
> > integer/half-integer boundaries.
> >
> > Vulkan, however, has much simpler requirements: the pixel center
> > is always half-integer, and the origin is always upper left. No
> > coordinate transform is needed - we just need to add <0.5, 0.5>.
> > This means that we can avoid using (and setting up) a uniform.
> >
> > I thought about adding more options to nir_lower_wpos_ytransform(),
> > but making a new pass that never even touched uniforms seemed simpler.
> >
> > Signed-off-by: Kenneth Graunke
> > ---
> > src/compiler/Makefile.sources| 1 +
> > src/compiler/nir/nir.h | 1 +
> > src/compiler/nir/nir_lower_wpos_center.c | 107 ++
+
> > 3 files changed, 109 insertions(+)
> > create mode 100644 src/compiler/nir/nir_lower_wpos_center.c
> >
> > diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources
> > index 97f9eb4..b8f2b49 100644
> > --- a/src/compiler/Makefile.sources
> > +++ b/src/compiler/Makefile.sources
> > @@ -212,6 +212,7 @@ 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_center.c \
> > nir/nir_lower_wpos_ytransform.c \
> > nir/nir_metadata.c \
> > nir/nir_move_vec_src_uses_to_dest.c \
> > diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
> > index a21a7bd..78913d3 100644
> > --- a/src/compiler/nir/nir.h
> > +++ b/src/compiler/nir/nir.h
> > @@ -2407,6 +2407,7 @@ typedef struct nir_lower_wpos_ytransform_options {
> >
> > bool nir_lower_wpos_ytransform(nir_shader *shader,
> > const nir_lower_wpos_ytransform_options
*options);
> > +bool nir_lower_wpos_center(nir_shader *shader);
> >
> > typedef struct nir_lower_drawpixels_options {
> > int texcoord_state_tokens[5];
> > diff --git a/src/compiler/nir/nir_lower_wpos_center.c b/src/compiler/nir/
nir_lower_wpos_center.c
> > new file mode 100644
> > index 000..d66109d
> > --- /dev/null
> > +++ b/src/compiler/nir/nir_lower_wpos_center.c
> > @@ -0,0 +1,107 @@
> > +/*
> > + * Copyright © 2015 Red Hat
> > + * Copyright © 2016 Intel Corporation
> > + *
> > + * 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"
> > +#include "program/prog_instruction.h"
> > +
> > +/**
> > + * This pass adds <0.5, 0.5> to all uses of gl_FragCoord.
> > + *
> > + * Run before nir_lower_io().
> > + *
> > + * For a more full featured pass, consider using
nir_lower_wpos_ytransform(),
> > + * which can handle pixel center integer / half integer, and origin lower
> > + * left / upper left transformations.
> > + *
> > + * This simple pass is primarily intended for use by Vulkan drivers on
> > + * hardware which provides an integer pixel center. Vulkan mandates that
> > + * the pixel center must be half-integer, and also that the coordinate
> > + * system's origin must be upper left. This means that there's no need
> > + * for a uniform - we can always just add a constant.
> > + */
> > +
> > +static void
> > +add_half_to_fragcoord(nir_builder *b, nir_intrinsic_instr *intr)
> > +{
> > + nir_ssa_def *wpos = &intr->dest.ssa;
> > +
> > + assert(intr->dest.is_ssa);
> > +
> > + b->cursor = nir_after_instr(&intr->instr);
> > +
> > + wpos = nir_fadd(b, wpos, nir_imm_vec4(b, 0.5f, 0.5f, 0.0f, 0.0f));
> > +
> > + nir_ssa_def_rewrite_uses_after(&intr->dest.ssa, nir_src_for_ssa(wpos),
> > +
