Ensure the following identities hold to match IEEE-754-2019 and upcoming NIR:
min(-0, +0) = -0
min(+0, -0) = -0
max(-0, +0) = +0
max(+0, -0) = +0
NVK uses this lowering. In a simple compute shader using fmin64 on an SSBO with
signed zero preserve required, testing the effect of this patch, the instruction
count goes from 47->52. Obviously I'm not thrilled by that but I also couldn't
find any obvious way of mitigating the issue. (Maybe NVIDIA has special hardware
support here. By instruction count, lowering all the way to int64 is a loss,
though I don't know how to count cycles on NVIDIA.)
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Konstantin Seurer <konstantin.seurer@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30075>
Here we remove the special handling for input params that was hard
to work with and unite it with the output and inout params.
Here a mediump test needs to be updated to what is a more expected
outcome anyway.
We also need to update the code that inserts software f64 to the
new way input params are handled.
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27108>
Instead, we replace every use of it with nir_def. Most of this commit
was generated by sed:
sed -i -e 's/dest.ssa/def/g' src/**/*.h src/**/*.c src/**/*.cpp
A few manual fixups were required in lima and the nir_legacy code.
Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24674>
Instead, we replace it directly with nir_def. We could replace it with
nir_dest but the next commit gets rid of that so this avoids unnecessary
churn. Most of this commit was generated by sed:
sed -i -e 's/dest.dest.ssa/def/g' src/**/*.h src/**/*.c src/**/*.cpp
There were a few manual fixups required in the nir_legacy.c and
nir_from_ssa.c as nir_legacy_reg and nir_parallel_copy_entry both have a
similar pattern.
Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24674>
With no registers seen, it is now a no-op.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Faith Ekstrand <faith.ekstrand@collabora.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24432>
Done by hand at each call site but going very quickly with funny Vim motions and
common regexes. This is a very common idiom in NIR.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23807>
There's plenty of places we can use these new and shiny helpers, so
let's clean up the code a bit.
Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Faith Ekstrand <faith.ekstrand@collabora.com>
Reviewed-by: Timur Kristóf <timur.kristof@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23460>
nir_ffma_imm has several variants that allows specific arguments to be
immediates. Use them for simplicity.
Reviewed-by: Faith Ekstrand <faith.ekstrand@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23179>
When doing nir_fsub(b, x, imm), we can negate the immediate value, and
replace the fsub with nir_fadd_imm() and get the same result. This makes
the code a bit shorter and easier to read.
Reviewed-by: Faith Ekstrand <faith.ekstrand@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23179>
This is generated by nir_lower_frexp, and if we leave fisfinite in place
then the late algebraic pass lowering it to this pattern will cause an
un-lowered fabs64 to be emitted.
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22083>
Builds on the work of !15121. This gets to delete even more code
because many drivers shared a lot of code for i2b and f2b.
No shader-db or fossil-db changes on any Intel platform.
v2: Rebase on 1a35acd8d9.
v3: Update a comment in nir_opcodes_c.py. Suggested by Konstantin.
v4: Another rebase. Remove f2b stuff from Midgard.
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20509>
Since we now depend on C11, we know that we have support for the C99
math functionality. So let's drop the c99_math.h compatibility wrapper,
and just include <math.h> directly.
Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Reviewed-by: Alyssa Rosenzweig <alyssa@collabora.com>
Reviewed-by: Eric Engestrom <eric@engestrom.ch>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16812>
I was doing math manually in a lowering pass for converting a division to
a ushr, and this will let the pass be expressed more naturally.
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6378>
It was always fneu but naming it fne causes confusion from time to time. So
lets rename it. Later we also want to add other unordered and fne, this is
a smaller preparation for that.
Signed-off-by: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6377>
Those are now handled by nir_lower_int64() which has native NIR
implementations.
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Acked-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5588>
NVIDIA hardware doesn't have an equivilant to bfi, but we do already have
a lowering for bitfield_insert->bfi.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5373>
Currently when lowering mod() we add an extra instruction so if
mod(a,b) == b then 0 is returned instead of b, as mathematically
mod(a,b) is in the interval [0, b).
But Vulkan spec has relaxed this restriction, and allows the result to
be in the interval [0, b].
For the OpenGL case, while the spec does not allow this behaviour, due
the allowed precision errors we can end up having the same result, so
from a practical point of view, this behaviour is allowed (see
https://github.com/KhronosGroup/VK-GL-CTS/issues/51).
This commit takes this in account to remove the extra instruction
required to return 0 instead.
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4118>
Currently when lowering mod() we add an extra instruction so if
mod(a,b) == b then 0 is returned instead of b, as mathematically
mod(a,b) is in the interval [0, b).
But Vulkan spec has relaxed this restriction, and allows the result to
be in the interval [0, b].
This commit takes this in account to remove the extra instruction
required to return 0 instead.
Reviewed-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/2922>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/2922>
v2:
- Replace hard coded value with DBL_MIN (Connor).
v3:
- Have into account the FLOAT_CONTROLS_DENORM_PRESERVE_FP64
flag (Caio).
Signed-off-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com>
Signed-off-by: Andres Gomez <agomez@igalia.com>
Reviewed-by: Connor Abbott <cwabbott0@gmail.com> [v2]
One advantage of this is that we no longer need to run in a loop because
the new framework handles lowering instructions added by lowering.
Reviewed-by: Eric Anholt <eric@anholt.net>
Unless source modifiers are present, fmov and imov are the same.
There's no good reason for having two helpers.
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
Acked-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
The nested fma calls were supposed to implement
x_new = x + x * (1 - x*src),
but instead current code is equivalent to
x_new = x - x * (1 - x*src).
The result is that Newton-Raphson steps don't improve precision at all.
This patch fixes this problem.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110435
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Instead of trusting the caller to already have created a softfp64
function shader and added all its functions to our shader, we simply
take the softfp64 shader as an argument and do the function inlining
ouselves. This means that there's no more nasty functions lying around
that the caller needs to worry about cleaning up.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
We already have one internally for int64 but we don't have a similar one
for doubles so we'll have to make one.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Use the trick of adding and then subtracting 2**52 (52 is the number of
explicit mantissa bits a double-precision floating-point value has) to
implement round-to-even.
Cuts the number of instructions on SKL of the piglit test
fs-roundEven-double.shader_test from 109 to 21.
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
NIR metadata validation verifies that the debug bit was unset (by a call
to nir_metadata_preserve) if a NIR optimization pass made progress on
the shader. With the expectation that the NIR shader consists of only a
single main function, it has been safe to call nir_metadata_preserve()
iff progress was made.
However, most optimization passes calculate progress per-function and
then return the union of those calculations. In the case that an
optimization pass makes progress only on a subset of the functions in
the shader metadata validation will detect the debug bit is still set on
any unchanged functions resulting in a failed assertion.
This patch offers a quick solution (short of a larger scale refactoring
which I do not wish to undertake as part of this series) that simply
unsets the debug bit on unchanged functions.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
