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>
This is much less precise than the cycle counter register, but
the cycle counter register is not available on apple platforms
(and on linux, it requires a kernel module for allowing user mode
access).
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>
The ISB (instruction synchronization barrier) might be too heavy for
START/STOPTIMER use but should be more accurate in checkasm where the
timing overhead is subtracted.
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>
Ported from arm NEON and added vector_dmul_scalar.
Functions between 1.5 and 5 times faster than the C implementations
using Apple's clang-503.0.19 on A7.
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.
Jonathan Wright
Martin Storsjö
Peter Collingbourne
Diego Biurrun
James Almer
Timothy Gu
Janne Grunau
Janne Grunau