Widens the given bit mask by a multiplier, meaning that it will
replicate each bit by that amount.
For example: 0b101 widened by 2 will become: 0b110011
This is typically used in shader I/O to transform a 64-bit
writemask to a 32-bit writemask.
Moving this function here because it is used in multiple places.
Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14005>
this is a standardized (and very slightly improved for usability) version
of the macro that has been copied into every vulkan driver
includes fixup from Rob Clark <robclark@freedesktop.org>
Reviewed-by: Rob Clark <robclark@freedesktop.org>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9191>
While the documentation for _BitScanReverse64 on MSDN says that it's
available on ARM, this isn't true. It's only available on ARM64. So
let's match reality.
Signed-off-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Acked-by: Matt Turner <mattst88@gmail.com>
bitcount is free from the pipe header dependencies that make u_math.h hard
to include by non-gallium specific code, so move it to bitscan.h. bitscan.h
is included by u_math.h so existing references will continue working.
Signed-off-by: Kevin Strasser <kevin.strasser@intel.com>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Suggested-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Eduardo Lima Mitev <elima@igalia.com>
The new name make the zero-input behavior more obvious. The next
patch adds a new function with different zero-input behavior.
Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Suggested-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Otherwise we'll get errors such as
error: conflicting types for ‘ffs’
error: conflicting types for ‘ffsll’
We might want to improve the heuristics and provide a definition only
when a native one is missing. We can address that at a later stage.
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Fix build error with clang.
Compiling src/compiler/glsl/link_varyings.cpp ...
In file included from src/compiler/glsl/link_varyings.cpp:33:
In file included from src/compiler/glsl/glsl_symbol_table.h:34:
In file included from src/compiler/glsl/ir.h:33:
In file included from src/compiler/glsl_types.h:29:
/usr/include/string.h:518:12: error: exception specification in declaration does not match previous declaration
extern int ffs (int __i) __THROW __attribute__ ((__const__));
^
src/util/bitscan.h:51:13: note: expanded from macro 'ffs'
^
src/util/bitscan.h:96:18: note: previous declaration is here
const int i = ffs(*mask) - 1;
^
src/util/bitscan.h:51:13: note: expanded from macro 'ffs'
^
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97952
Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Reviewed-by: Timothy Arceri <timothy.arceri@collabora.com>
v2: Split into two patches.
v3: Fix off by one problem.
Signed-off-by: Mathias Fröhlich <Mathias.Froehlich@web.de>
Reviewed-by: Brian Paul <brianp@vmware.com>
Tested-by: Brian Paul <brianp@vmware.com>
As requested with the initial creation of util/bitscan.h
now move other bitscan related functions into util.
v2: Split into two patches.
Signed-off-by: Mathias Fröhlich <Mathias.Froehlich@web.de>
Tested-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
The functions are also useful for mesa.
Introduce src/util/bitscan.{h,c}. Move ffs function
implementations from src/mesa/main/imports.{h,c}.
Move bit scan related functions from
src/gallium/auxiliary/util/u_math.h. Merge platform
handling with what is available from within mesa.
v2: Try to fix MSVC compile.
Reviewed-by: Brian Paul <brianp@vmware.com>
Tested-by: Brian Paul <brianp@vmware.com>
Signed-off-by: Mathias Fröhlich <Mathias.Froehlich@web.de>
Erik Faye-Lund
Timur Kristóf
Marek Olšák
Mike Blumenkrantz
Kevin Strasser
Pierre Moreau
Ian Romanick
Emil Velikov
Vinson Lee
Mathias Fröhlich