This defines a new BRW_ANALYSIS object which wraps the register
pressure computation code along with its result. For the rationale
see the previous commits converting the liveness and dominance
analysis passes to the IR analysis framework.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
It makes sense to keep the result of analysis passes independent from
the IR itself. Instead of representing the idom tree as a pointer in
each basic block pointing to its immediate dominator, the whole
dominator tree is represented separately from the IR as an array of
pointers inside the idom_tree object. This has the advantage that
it's no longer possible to use stale dominance results by accident
without having called require() beforehand, which makes sure that the
idom tree is recalculated if necessary.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
This only does half of the work. The actual representation of the
idom tree is left untouched, but the computation algorithm is moved
into a separate analysis result class wrapped in a BRW_ANALYSIS
object, along with the intersect() and dump_domtree() auxiliary
functions in order to keep things tidy.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
This involves wrapping vec4_live_variables in a BRW_ANALYSIS object
and hooking it up to invalidate_analysis() so it's properly
invalidated. Seems like a lot of churn but it's fairly
straightforward. The vec4_visitor invalidate_ and
calculate_live_intervals() methods are no longer necessary after this
change.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
This involves wrapping fs_live_variables in a BRW_ANALYSIS object and
hooking it up to invalidate_analysis() so it's properly invalidated.
Seems like a lot of churn but it's fairly straightforward. The
fs_visitor invalidate_ and calculate_live_intervals() methods are no
longer necessary after this change.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
This could be improved somewhat with additional validation of the
calculated live in/out sets and by checking that the calculated live
intervals are minimal (which isn't strictly necessary to guarantee the
correctness of the program). This should be good enough though to
catch accidental use of stale liveness results due to missing or
incorrect analysis invalidation.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
This could be improved somewhat with additional validation of the
calculated live in/out sets and by checking that the calculated live
intervals are minimal (which isn't strictly necessary to guarantee the
correctness of the program). This should be good enough though to
catch accidental use of stale liveness results due to missing or
incorrect analysis invalidation.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
This removes the dependency of fs_live_variables on fs_visitor. The
IR analysis framework requires the analysis result to be constructible
with a single argument -- The second argument was redundant anyway.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
This makes the structure of the vec4 live intervals calculation more
similar to the FS back-end liveness analysis code. The non-CF-aware
start/end computation is moved into the same pass that calculates the
block-local def/use sets, which saves quite a bit of code, while the
CF-aware start/end computation is moved into a separate
compute_start_end() function as is done in the FS back-end.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
This moves the following methods that are currently defined in
vec4_visitor (even though they are side products of the liveness
analysis computation) and are already implemented in
brw_vec4_live_variables.cpp:
> int var_range_start(unsigned v, unsigned n) const;
> int var_range_end(unsigned v, unsigned n) const;
> bool virtual_grf_interferes(int a, int b) const;
> int *virtual_grf_start;
> int *virtual_grf_end;
It makes sense for them to be part of the vec4_live_variables object,
because they have the same lifetime as other liveness analysis results
and because this will allow some extra validation to happen wherever
they are accessed in order to make sure that we only ever use
up-to-date liveness analysis results.
The naming of the virtual_grf_start/end arrays was rather misleading,
they were indexed by variable rather than by vgrf, this renames them
start/end to match the FS liveness analysis pass. The churn in the
definition of var_range_start/end is just in order to avoid a
collision between the start/end arrays and local variables declared
with the same name.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
This moves the following methods that are currently defined in
fs_visitor (even though they are side products of the liveness
analysis computation) and are already implemented in
brw_fs_live_variables.cpp:
> bool virtual_grf_interferes(int a, int b) const;
> int *virtual_grf_start;
> int *virtual_grf_end;
It makes sense for them to be part of the fs_live_variables object,
because they have the same lifetime as other liveness analysis results
and because this will allow some extra validation to happen wherever
they are accessed in order to make sure that we only ever use
up-to-date liveness analysis results.
This shortens the virtual_grf prefix in order to compensate for the
slightly increased lexical overhead from the live_intervals pointer
dereference.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
Have fun reading through the whole back-end optimizer to verify
whether I've missed any dependency flags -- Or alternatively, just
trust that any mistake here will trigger an assertion failure during
analysis pass validation if it ever poses a problem for the
consistency of any of the analysis passes managed by the framework.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
I've deliberately separated this from the general analysis pass
infrastructure in order to discuss it independently. The dependency
classes defined here refer to state changes of several objects of the
program IR, and are fully orthogonal and expected to change less often
than the set of analysis passes present in the compiler back-end.
The objective is to avoid unnecessary coupling between optimization
and analysis passes in the back-end. By doing things in this way the
set of flags to be passed to invalidate_analysis() can be determined
from knowledge of a single optimization pass and a small set of well
specified dependency classes alone -- IOW there is no need to audit
all analysis passes to find out which ones might be affected by
certain kind of program transformation performed by an optimization
pass, as well as the converse, there is no need to audit all
optimization passes when writing a new analysis pass to find out which
ones can potentially invalidate the result of the analysis.
The set of dependency classes defined here is rather conservative and
mainly based on the requirements of the few analysis passes already
part of the back-end. I've also used them without difficulty with a
few additional analysis passes I've written but haven't yet sent for
review.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
The invalidate_analysis() method knows what analysis passes there are
in the back-end and calls their invalidate() method to report changes
in the IR. For the moment it just calls invalidate_live_intervals()
(which will eventually be fully replaced by this function) if anything
changed.
This makes all optimization passes invalidate DEPENDENCY_EVERYTHING,
which is clearly far from ideal -- The dependency classes passed to
invalidate_analysis() will be refined in a future commit.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
Motivated in detail in the source code. The only piece missing here
from the analysis pass infrastructure is some sort of mechanism to
broadcast changes in the IR to all existing analysis passes, which
will be addressed by a future commit. The analysis_dependency_class
enum might seem a bit silly at this point, more interesting dependency
categories will be defined later on.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
brw_vec4.h (in particular vec4_visitor) is logically a user of the
live variables analysis pass, not the other way around.
brw_vec4_live_variables.h requires the definition of some VEC4 IR data
structures to compile, but those can be obtained directly from
brw_ir_vec4.h without including brw_vec4.h.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
brw_fs.h (in particular fs_visitor) is logically a user of the live
variables analysis pass, not the other way around.
brw_fs_live_variables.h requires the definition of some FS IR data
structures to compile, but those can be obtained directly from
brw_ir_fs.h without including brw_fs.h. The dependency of
fs_live_variables on fs_visitor is rather accidental and will be
removed in a future commit, a forward declaration is enough for the
moment.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
When this commit was originally written, these two structures had the
exact same name. Subsequently in commit 12a8f2616a (intel/compiler:
Fix C++ one definition rule violations) they were renamed.
Original commit message:
> These two structures have exactly the same name which prevents the two
> files from being included at the same time and could cause serious
> trouble in the future if it ever leads to a (silent) violation of the
> C++ one definition rule.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
This reflects the natural dependency relationship between brw_cfg.h
and brw_shader.h. brw_cfg.h only requires the base IR definitions
which are now part of a separate header.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
This pulls out the i965 IR definitions into a separate file and leaves
the top-level backend_shader structure and back-end compiler entry
points in brw_shader.h. The purpose is to keep things tidy and
prevent a nasty circular dependency between brw_cfg.h and
brw_shader.h. The logical dependency between these data structures
looks like:
backend_shader (brw_shader.h) -> cfg_t (brw_cfg.h)
-> bblock_t (brw_cfg.h) -> backend_instruction (brw_shader.h)
This circular header dependency is currently resolved by using forward
declarations of cfg_t/bblock_t in brw_shader.h and having brw_cfg.h
include brw_shader.h, which seems backwards and won't work at all when
the forward declarations of cfg_t/bblock_t are no longer sufficient in
a future commit.
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4012>
Several files had a initial comment about the purpose of such files,
including a reference that the NIR linker was implemented with just
ARB_gl_spirv in mind.
Since the nice job Timothy is doing to use the NIR linker on GLSL,
that is not true anymore, so let's remove that reference and also
tweak some other comments.
Acked-by: Timothy Arceri <tarceri@itsqueeze.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4081>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4081>
Timothy Arceri
Vasily Khoruzhick
Francisco Jerez
Christian Gmeiner
Thong Thai
Alejandro Piñeiro
Eric Engestrom
Pierre-Eric Pelloux-Prayer
Samuel Pitoiset