As explained in bug 1111355, having avx enabled appears to change the
alignment behavior of alloca (apparently adding an extra 16 bytes) of
padding/alignment (and using 32-byte alignment instead of 16-byte). The
suggestion of using __bultin_alloca_with_align in bug 1111355 didn't fix
the problem, so this seems to be the best available workaround, given
that this code, which should perhaps better be written in assembly, is
written in C++.
Interestingly, this is NOT fixed by #pragma GCC target ("arch=x86-64").
(I determined the (undocumented) name for the default -march value on
x86_64 from the gcc source code (gcc/config/i386/i386.c, function
ix86_option_override_internal, code that sets opts->x_ix86_arch_string .)
I confirmed that this sets the same macros based on the empty diff
between the output of 'gcc -E -dM -x c++ /dev/null' and 'gcc -E -dM -x
c++ -march=x86-64 /dev/null', which was not an empty diff for other
-march values (e.g., k8).)
I confirmed that the push_options and pop_options actually work by
putting the push/pop pair around a different (earlier) function, and
testing that this did not fix the bug (with the pop_options before
NS_InvokeByIndex).
See the gcc documentation at:
https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Function-Specific-Option-Pragmas.htmlhttps://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Function-Attributes.htmlhttps://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/i386-and-x86-64-Options.html
--HG--
extra : transplant_source : %DA%7CJ4H%DE%80%15%84%0D%116%85Q%9A%F9%2C%D1v%16
There are, sadly, many combinations of linkage in use throughout the tree.
The main differentiator, though, is between program/libraries related to
Gecko or not. Kind of. Some need mozglue, some don't. Some need dependent
linkage, some standalone.
Anyways, these new templates remove the need to manually define the
right dependencies against xpcomglue, nspr, mozalloc and mozglue
in most cases.
Places that build programs and were resetting MOZ_GLUE_PROGRAM_LDFLAGS
or that build libraries and were resetting MOZ_GLUE_LDFLAGS can now
just not use those Gecko-specific templates.
This fixes the download panel issue, and brings us revs 727721e5d8ac,
844b142d8111 and 236989b3a807 as a bonus. Remove the unmaintained
OpenBSD/amd64 specific versions.
OS_LIBS for libraries that are not part of the gecko tree, EXTRA_LIBS for
libraries, such as NSPR, that are in the tree, but are not handled by
moz.build just yet. Those EXTRA_LIBS may also come from a system library.
However, in cases where the expanded variables are always empty for the
in-tree case, OS_LIBS is used (as for, e.g. MOZ_ZLIB_LIBS). OS_LDFLAGS is
used exclusively for non-library linker flags.
Always pass EXTRA_LIBS before OS_LIBS on linker command lines.
Forbid EXTRA_DSO_LDOPTS, SHARED_LIBRARY_LIBS and LIBS in Makefiles.
