iris: Initial commit of a new 'iris' driver for Intel Gen8+ GPUs.
This commit introduces a new Gallium driver for Intel Gen8+ GPUs,
named 'iris_dri.so' after the hardware.
Developed by:
- Kenneth Graunke (overall driver)
- Dave Airlie (shaders, conditional render, overflow query, Gen8 port)
- Chris Wilson (fencing, pinned memory, ...)
- Jordan Justen (compute shaders)
- Jason Ekstrand (image load store)
- Caio Marcelo de Oliveira Filho (tessellation control passthrough)
- Rafael Antognolli (auxiliary buffer fixes)
- The rest of the i965 contributors and the Mesa community
Turns out we can write to tiled images as well as read. This avoids
having to linearize or do the tiling in the shader.
Signed-off-by: Rob Clark <robdclark@gmail.com>
nir, glsl: move pixel_center_integer/origin_upper_left to shader_info.fs
On GLSL that info is set as a layout qualifier when redeclaring
gl_FragCoord, so somehow tied to a specific variable. But in practice,
they behave as a global of the shader. On ARB programs they are set
using a global OPTION (defined at ARB_fragment_coord_conventions), and
on SPIR-V using ExecutionModes, that are also not tied specifically to
the builtin.
This patch moves that info from nir variable and ir variable to nir
shader and gl_program shader_info respectively, so the map is more
similar to SPIR-V, and ARB programs, instead of more similar to GLSL.
FWIW, shader_info.fs already had pixel_center_integer, so this change
also removes some redundancy. Also, as struct gl_program also includes
a shader_info, we removed gl_program::OriginUpperLeft and
PixelCenterInteger, as it would be superfluous.
This change was needed because recently spirv_to_nir changed the order
in which execution modes and variables are handled, so the variables
didn't get the correct values. Now the info is set on the shader
itself, and we don't need to go back to the builtin variable to set
it.
Fixes: e68871f6a ("spirv: Handle constants and types before execution
modes")
v2: (Jason)
* glsl_to_nir: get the info before glsl_to_nir, while all the rest
of the info gathering is happening
* prog_to_nir: gather the info on a general info-gathering pass,
not on variable setup.
v3: (Jason)
* Squash with the patch that removes that info from ir variable
* anv: assert that OriginUpperLeft is true. It should be already
set by spirv_to_nir.
* blorp: set origin_upper_left on its core "compile fragment
shader", not just on some specific places (for this we added an
helper on a previous patch).
* prog_to_nir: no need to gather specifically this fragcoord modes
as the full gl_program shader_info is copied.
* spirv_to_nir: assert that we are a fragment shader when handling
this execution modes.
v4: (reported by failing gitlab pipeline #18750)
* state_tracker: update too due changes on ir.h/gl_program
v5:
* blorp: minor change after change on previous patch
* radeonsi: update due this change.
v6: (Timothy Arceri)
* prog_to_nir: remove extra whitespace
* shader_info: don't use :1 on origin_upper_left
* glsl: program.fs.origin_upper_left/pixel_center_integer can be
move out of the shader list loop
panfrost: Verify and print brx condition in disasm
The condition code in extended branches is repeated 8 times for unclear
reasons; accordingly, the code would be disassembled as "unknown5555",
"unknownAAAA", etc. This patch correctly masks off the lower two bits to
find the true code to print, verifying that the code is repeated as
believed to be necessary (providing some assurance for compiler quality
and an assert trip in case we encounter a shader in the wild that breaks
the convention).
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
discard and discard_if are both implemented with the branching pipeline
on Midgard; essentially, we branch to the end of the fragment shader in
a special "discard" mode, setting the condition as necessary.
Previously, we hardcoded the form of this instruction, which worked for
very simple shaders but was incorrect for anything remotely interesting.
This patch instead emits logical branches in the IR, which are flattened
to real discard ops the same way other branches are, allowing targets to
be computed correctly.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Previously, we only emitted compact branches; however, the offset range
of these branches is too small for many real world shaders. This patch
implements support for emitting extended branches and switches to always
using them for control flow. This incurs a code size and possibly
performance penalty, but expands the range of working shaders and
provides opportunity for further optimization.
Support for emitting compact branches is retained but this code path is
presently unused. In the future, we'll want to heuristically determine
which type of branch should be emitted for optimal codegen.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Midgard features "compact branches" and "extended branches", i.e.
corresponds to short jumps and far jumps. The form of the extended
branch was previously incorrect in the ISA headers; this patch corrects
it and updates the disassembler (simultaneous to preserve
bisectability).
Additionally, we fix some a corner case in the disassembly of extended
branches, and we now prefix extended branches with "brx", to visually
differentiate from compact branches prefixed with "br".
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
An if-else statement is compiled to a conditional branch (from the start
to the second block) and an unconditional branch (from the end of the
first block to the end of the else). We previously incorrectly computed
the block index of the unconditional branch to be exactly one after that
of the conditional branch, valid for a single if-else statement but
nothing fancier. This patch correctly computes the unconditional branch
target, fixing more complex if-else chains.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Each Midgard instruction is scheduled to a particular instruction type
("tag"). Presumably the hardware prefetches memory based on tag, so it
is required to report out the first tag to the command stream and the
next tag of a branch target. This procedure was implemented in two
separate parts of the compiler (one time with a slight bug relating to
empty blocks); this patch refactors to unite the two routines and solve
the bug when branching to empty blocks.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Historically, Panfrost debugging entailed the use of the LD_PRELOADable
`panwrap` tool. This setup is a tad fragile; Panfrost can be traced
directly without the intermediate layer. pantrace implements the
quivalent functionality of panwrap into Panfrost proper, allowing dumps
to work regardless of the kernel layer in use.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
The `panwrap` utility can be LD_PRELOAD'd into a GLES app, intercepting
communication between the driver and the kernel. Modern panwrap versions
do no processing of their own; instead, they create a trace directory.
This directory contains the following files:
- control.log: a line-by-line plain text file, denoting important
syscalls (mmaps and job submits) along with their arguments
- memory_*.bin, shader_*.bin: binary dumps of mapped memory
Together, these files contain enough information to reconstruct the
command stream and shaders of (at minimum) a single frame.
The `pandecode` utility takes this directory structure as input,
reconstructing the mapped memory and using the job submit command as an
entrypoint. It then walks the descriptors as the hardware would, parsing
and pretty-printing. Its final output is the pretty-printed command
stream interleaved with the disassembled shaders, suitable for driver
debugging. For instance, the behaviour of two driver versions (one
working, one broken) can be compared by diff'ing their decoded logs.
pandecode/decode.c was originally a part of `panwrap`; it is the oldest
living code in the project. Its history is generally not worth
preserving.
panwrap itself will continue to live downstream for the foreseeable
future, as it is specifically written for the vendor kernel. It is
possible, however, to produce equivalent traces directly from Panfrost,
bypassing the intermediate wrapping layer for well-behaved drivers.
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Kenneth Graunke