This eases actual development of the assembly functions, by only
allowing extension instructions within the sections that explicitly
enable them, instead of having all extensions enabled everywhere.
Signed-off-by: Martin Storsjö <martin@martin.st>
These are available since ARMv8.4-a and ARMv8.6-a respectively,
but can also be available optionally since ARMv8.2-a.
Check if ".arch armv8.2-a" and ".arch_extension {dotprod,i8mm}" are
supported, and check if the instructions can be assembled.
Current clang versions fail to support the dotprod and i8mm
features in the .arch_extension directive, but do support them
if enabled with -march=armv8.4-a on the command line. (Curiously,
lowering the arch level with ".arch armv8.2-a" doesn't make the
extensions unavailable if they were enabled with -march; if that
changes, Clang should also learn to support these extensions via
.arch_extension for them to remain usable here.)
Signed-off-by: Martin Storsjö <martin@martin.st>
This avoids build errors if such features are enabled while targeting
another binary format. (Using such features on other platforms
might require some other form of signaling/setup though, but
the ELF specific .note section isn't applicable at least.)
Signed-off-by: Martin Storsjö <martin@martin.st>
This patch adds optional support for Arm Pointer Authentication Codes.
PAC support is turned on or off at compile time using additional
compiler flags. Unless any of these is enabled explicitly, no additional
code will be emitted at all.
Signed-off-by: André Kempe <andre.kempe@arm.com>
Signed-off-by: Martin Storsjö <martin@martin.st>
Add Branch Target Identifiers (BTIs) to all functions defined in
AArch64 assembly files. Most of the BTI landing pads are added
automatically by the 'function' macro.
BTI support is turned on or off at compile time based on the presence
of the __ARM_FEATURE_BTI_DEFAULT feature macro.
A binary compiled with BTI support can be executed on an Armv8-A
processor without BTI support because the instructions are defined in
NOP space.
Signed-off-by: Jonathan Wright <jonathan.wright@arm.com>
Signed-off-by: Elijah Ahmad <elijah.ahmad@arm.com>
Signed-off-by: Martin Storsjö <martin@martin.st>
On windows and darwin (and modern android), the x18 register is reserved
and shouldn't be modified by user code, while it is freely available on
linux. Strictly avoid it, to keep the assembly code portable.
This would have helped catch the issue fixed in 872790b1f9
immediately.
Signed-off-by: Martin Storsjö <martin@martin.st>
As of LLVM r368102, Clang will set a pointer tag in bits 56-63 of the
address of a global when compiling with -fsanitize=hwaddress. This requires
an adjustment to assembly code that takes the address of such globals: the
code cannot use the regular R_AARCH64_ADR_PREL_PG_HI21 relocation to refer
to the global, since the tag would take the address out of range. Instead,
the code must use the non-checking (_NC) variant of the relocation (the
link-time check is substituted by a runtime check).
This change makes the necessary adjustment in the movrel macro, where it is
needed when compiling with -fsanitize=hwaddress.
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Martin Storsjö
Reviewed-by: Janne Grunau
As .rodata isn't one of the default created sections for COFF, it was
created as a read-write data section. By using the default .rdata
section name for COFF, it automatically becomes a read-only data section.
The existing ".section .rodata" works as intended for ELF though.
This is based on an original patch and diagnose by Tom Tan
<Tom.Tan@microsoft.com>.
Signed-off-by: Martin Storsjö <martin@martin.st>
The extra space got included as part of the expansion of ELF, which
later interfered with gas-preprocessor which earlier only stripped out
leftover lines starting with '#' if the line started with that char.
Signed-off-by: Martin Storsjö <martin@martin.st>
On windows, the offset for the relocation doesn't get stored in
the relocation itself, but as an unsigned immediate in the opcode.
Therefore, negative offsets has to be handled via a separate sub
instruction, just as on MachO.
Signed-off-by: Martin Storsjö <martin@martin.st>
This fixes building with clang for linux with PIC enabled.
This is cherrypicked from libav commit
8847eeaa14.
Signed-off-by: Martin Storsjö <martin@martin.st>
With apple tools, the linker fails with errors like these, if the
offset is negative:
ld: in section __TEXT,__text reloc 8: symbol index out of range for architecture arm64
This is cherry-picked from libav commit
c44a8a3eab.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
With apple tools, the linker fails with errors like these, if the
offset is negative:
ld: in section __TEXT,__text reloc 8: symbol index out of range for architecture arm64
Signed-off-by: Martin Storsjö <martin@martin.st>
Both gnu as and clang treat lines starting with '#' as comments if they
aren't consumed by the C-style preprocessor.
Using '//' does not work with clang since comments are removed before
macro expansion.
This fixes building in PIC mode with gas. The examples in the gas
manual showed using a # here even though gas itself actually didn't
support that syntax (and the gas test suite only tests it without
the extra hash sign).
CC: libav-stable@libav.org
Signed-off-by: Martin Storsjö <martin@martin.st>
NEON and VFP are currently mandatory for all ARMv8 profiles. Both are
handled as extensions as far as cpuflags are concerned. This is
consistent with handling x86_64 which always has SSE2, but still
handles it as an extension.
This allows masking CPU features with the -cpuflags avconv option
which is useful for testing different optimisations without rebuilding.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This reduces the number of false dependencies on header files and
speeds up compilation.
Originally committed as revision 22407 to svn://svn.ffmpeg.org/ffmpeg/trunk
Consistently apply this rule: the guard name is obtained from the
filename by stripping the leading "lib", converting '/' and '.' to
'_' and uppercasing the resulting name. Guard names in the root
directory have to be prefixed by "FFMPEG_".
Originally committed as revision 15120 to svn://svn.ffmpeg.org/ffmpeg/trunk
Patch by Zuxy Meng: zuxy meng gmail com
Original thread:
[FFmpeg-devel] [PATCH] Pure, const and malloc attributes to libavutil
Date: 03/18/2008 6:09 AM
Originally committed as revision 12489 to svn://svn.ffmpeg.org/ffmpeg/trunk
Martin Storsjö
Andre Kempe
Jonathan Wright
Peter Collingbourne
Janne Grunau
Diego Biurrun
Ronald S. Bultje
Mans Rullgard
Justin Ruggles
Stefano Sabatini
Zuxy Meng
Benoit Fouet