Source: dxvk
Version: 2.6.1-1
Severity: serious
Tags: upstream ftbfs experimental
Justification: built successfully in the past on armhf
dxvk 2.6.1 with DXVK Native enabled doesn't build successfully on armhf:
c++ -Isrc/wsi/libwsi.a.p -Isrc/wsi -I../src/wsi -Iinclude -I../include -I../include/vulkan/include -I../include/spirv/include -Iinclude/native -I../include/native -I../include/native/windows -I../include/native/directx -I../subprojects/libdisplay-info/
include -I/usr/include/SDL2 -fdiagnostics-color=always -D_GLIBCXX_ASSERTIONS=1 -Wall -Winvalid-pch -Wextra -std=c++17 -Wimplicit-fallthrough -Wno-missing-field-initializers -Wno-unused-parameter -Wno-misleading-indentation -Wno-cast-function-type -Wno-
unused-const-variable -Wno-missing-braces -DDXVK_WSI_SDL2 -g -O2 -ffile-prefix-map=/build/reproducible-path/dxvk-2.6.1=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_TIME_
BITS=64 -Wdate-time -D_FORTIFY_SOURCE=2 -fPIC -D_GNU_SOURCE=1 -D_REENTRANT -MD -MQ src/wsi/libwsi.a.p/wsi_platform.cpp.o -MF src/wsi/libwsi.a.p/wsi_platform.cpp.o.d -o src/wsi/libwsi.a.p/wsi_platform.cpp.o -c ../src/wsi/wsi_platform.cpp
In file included from ../src/wsi/../util/util_string.h:10,
from ../src/wsi/../util/util_env.h:3,
from ../src/wsi/wsi_platform.cpp:4: ../src/wsi/../util/util_bit.h:12:2: error: #error "Unknown CPU Architecture"
—
https://buildd.debian.org/status/fetch.php?pkg=dxvk&arch=armhf&ver=2.6.1-1&stamp=1744304328&raw=0
A crude way to mitigate this issue would be to limit compilation of
DXVK Native to amd64, i386 and arm64 only, after which this bug could
be downgraded to wishlist until a porter steps in to help; please let me
know if you would like a MR for this. But of course ideally DXVK Native
would be portable (I don't think there's any fundamental reason why it
can't be compilable on every architecture).
There seem to be two places in the dxvk codebase that #error out if the
CPU architecture is not recognised.
1. src/util/util_bit.h
There is some conditional-compilation of this form (pseudocode):
#if (architecture is x86_64 or i386)
#define DXVK_ARCH_X86
#if (architecture is x86_64)
#define DXVK_ARCH_X86_64
#endif
#elif (architecture is aarch64)
#define DXVK_ARCH_ARM64
#else
#error
#endif
But all the conditional compilation further down the file seems to have a portable "#else" fallback available, so probably it would be OK to replace
the "#error" with just not defining any of the helper macros on unrecognised architectures?
2. src/util/sync/sync_spinlock.h
The implementation of dxvk::sync::spin calls _mm_pause() on x86, uses inline assembly to call "yield" on aarch64, and emits a #error "Pause/Yield not implemented for this architecture." otherwise. For this to be portable, it would need a fallback for other architectures.
Looking at
https://codesearch.debian.net/search?q=_mm_pause&literal=1
it seems that a reasonable implementation for other architectures would
be to do nothing at all (and porters can contribute an implementation
for their architecture if they want to).
smcv
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