In the C23 standard unreachable() is now a predefined function-like
macro in <stddef.h>
See https://android.googlesource.com/platform/bionic/+/HEAD/docs/c23.md#is-now-a-predefined-function_like-macro-in
And this causes build errors when building for C23:
-----------------------------------------------------------------------
In file included from ../src/util/log.h:30,
from ../src/util/log.c:30:
../src/util/macros.h:123:9: warning: "unreachable" redefined
123 | #define unreachable(str) \
| ^~~~~~~~~~~
In file included from ../src/util/macros.h:31:
/usr/lib/gcc/x86_64-linux-gnu/14/include/stddef.h:456:9: note: this is the location of the previous definition
456 | #define unreachable() (__builtin_unreachable ())
| ^~~~~~~~~~~
-----------------------------------------------------------------------
So don't redefine it with the same name, but use the name UNREACHABLE()
to also signify it's a macro.
Using a different name also makes sense because the behavior of the
macro was extending the one of __builtin_unreachable() anyway, and it
also had a different signature, accepting one argument, compared to the
standard unreachable() with no arguments.
This change improves the chances of building mesa with the C23 standard,
which for instance is the default in recent AOSP versions.
All the instances of the macro, including the definition, were updated
with the following command line:
git grep -l '[^_]unreachable(' -- "src/**" | sort | uniq | \
while read file; \
do \
sed -e 's/\([^_]\)unreachable(/\1UNREACHABLE(/g' -i "$file"; \
done && \
sed -e 's/#undef unreachable/#undef UNREACHABLE/g' -i src/intel/isl/isl_aux_info.c
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/36437>
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>
First, allow the case for negative powers of two. Then ensure that we
use the absolute value of the non-constant value to calculate the
quotient -- this was hinted in the code by the name 'uq'.
This fixes an issue when 'd' is positive and 'n' is negative. The
ishr will propagate the negative sign and we'll use nir_ineg() again,
incorrectly.
v2: First version used only ishr, but that isn't sufficient, since it
never can produce a zero as a result. (Jason)
Allow negative powers of two. (Caio)
Fixes: 74492ebad9 "nir: Add a pass for lowering integer division by constants"
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
v2: remove & operator in a couple of memsets
add some memsets
v3: fixup lima
Signed-off-by: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net> (v2)
It's a reasonably well-known fact in the world of compilers that integer
divisions by constants can be replaced by a multiply, an add, and some
shifts. This commit adds such an optimization to NIR for easiest case
of udiv. Other division operations will be added in following commits.
In order to provide some additional driver control, the pass takes a
minimum bit size to optimize.
Reviewed-by: Ian Romanick ian.d.romanick@intel.com
Antonio Ospite