Some debuggers/profilers use this metadata to determine which function a
given instruction is in; without it they get can confused by local labels
(if you haven't stripped those). On the other hand, some tools are still
confused even with this metadata. e.g. this fixes `gdb`, but not `perf`.
Currently only implemented for ELF.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
The REP_RET workaround is only needed on old AMD cpus, and the labels clutter
up the symbol table and confuse debugging/profiling tools, so use EQU to
create SHN_ABS symbols instead of creating local labels. Furthermore, skip
the workaround completely in functions that definitely won't run on such cpus.
Note that EQU is just creating a local label when using nasm instead of yasm.
This is probably a bug, but at least it doesn't break anything.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
When allocating stack space with a larger alignment than the known stack
alignment a temporary register is used for storing the stack pointer.
Ensure that this isn't one of the registers used for passing arguments.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
* Correctly handle FMA instructions with memory operands.
* Print a warning if FMA instructions are used without the correct cpuflag.
* Simplify the instantiation code.
* Clarify documentation.
Only the last operand in FMA3 instructions can be a memory operand. When
converting FMA4 instructions to FMA3 instructions we can utilize the fact
that multiply is a commutative operation and reorder operands if necessary
to ensure that a memory operand is used only as the last operand.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
The .text section is already 16-byte aligned by default on all supported
platforms so `SECTION_TEXT` isn't any different from `SECTION .text`.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
Change ALLOC_STACK to always align the stack before allocating stack space for
consistency. Previously alignment would occur either before or after allocating
stack space depending on whether manual alignment was required or not.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
Emulation requires a temporary register if arguments 1 and 4 are the same; this
doesn't obey the semantics of the original instruction, so we can't emulate
that in x86inc.
Also add pmacsdql emulation.
Signed-off-by: Henrik Gramner <henrik@gramner.com>
Signed-off-by: Anton Khirnov <anton@khirnov.net>
Silences warning(s) like:
libavcodec/x86/fft.asm:93: warning: section flags ignored on
section redeclaration
The cause of this warning is that because `struc` and `endstruc`
attempts to revert to the previous section state [1].
The section state is stored in the macro __SECT__, defined by
x86inc.asm to be `.note.GNU-stack ...`, through the `SECTION`
directive [2].
Thus, the `.note.GNU-stack` section is defined twice
(once in x86inc.asm, once during `endstruc`), causing the warning.
That is the first part of the commit: using the primitive `[section]` format
for .note.GNU-stack etc., which does not update `__SECT__` [2].
That fixes only half of the problem. Even without any `SECTION` directives,
`__SECT__` is predefined as `.text`, which conflicting with the later
`SECTION_TEXT` (which expands to `.text align=16`).
[1]: http://www.nasm.us/doc/nasmdoc6.html#section-6.4
[2]: http://www.nasm.us/doc/nasmdoc6.html#section-6.3
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
This is so we can sync to x264's version of FMA4 support.
This partialy reverts commit 79687079a97a039c325ab79d7a95920d800b791f.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Automatically use VEX-encoding in AVX/AVX2/XOP/FMA3/FMA4
functions for all instructions that exists in a VEX-encoded
version.
This change makes it easier to extend existing code to use AVX2.
Also add support for AVX emulation of a few instructions that
were missing before.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Prevents a crash if the misaligned exception mask bit is
cleared for some reason.
Misaligned SSE functions are only used on AMD Phenom CPUs
and the benefit is miniscule. They also require modifying
the MXCSR control register and by removing those functions
we can get rid of that complexity altogether.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Store XMM6 and XMM7 in the shadow space in functions that
clobbers them. This way we don't have to adjust the stack
pointer as often, reducing the number of instructions as
well as code size.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
SWAP with >=3 named (rather than numbered) args
PERMUTE followed by SWAP with 2 named args
used to produce the wrong permutation
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Now RET checks whether it immediately follows a branch, so the
programmer dosen't have to keep track of that condition. REP_RET
is still needed manually when it's a branch target, but that's
much rarer.
The implementation involves lots of spurious labels, but that's OK
because we strip them.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
The "CentaurHauls family 6 model 9 stepping 8" family of CPUs
(flags: fpu vme de pse tsc msr cx8 sep mtrr pge mov pat mmx fxsr sse
up rng rng_en ace ace_en) SIGILLs on long nop codes.
Signed-off-by: Martin Storsjö <martin@martin.st>
The new name is more descriptive and will allow defining a separate
public prefix for externally visible library symbols.
Signed-off-by: Diego Biurrun <diego@biurrun.de>
Use this in VP8/H264-8bit loopfilter functions so they can be used if
there is no aligned stack (e.g. MSVC 32bit or ICC 10.x).
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
It appears that something goes wrong in old nasm versions when the
%+ operator is used in the last argument of a macro invocation and
this argument is tested with %ifdef within the macro. This patch
rearranges the macro arguments such that the %+ operator is never
used in the last argument.
nasm does not support 'CPU foonop' directives. This adds a configure
test for the directive and uses it only if supported.
Signed-off-by: Mans Rullgard <mans@mansr.com>
