The accelerated convolutional decoder uses SSSE3 instructions such
as PSIGNW (via _mm_sign_epi16) which go beyond what SSE3 offers. So
let's make sure we use the right compiler flag (-mssse3) and also the
right runtime check.
Without this patch, we would use illegal instructions e.g. on Opteron
Gen3 such as Opteron 2427, which are also used as build.opensuse.org
build hosts (build31 through build36) where we wouldn't pass "make
check" as a result.
Change-Id: I2754164384109f2821fd98ffb48f625893f2923d
Fixes: OS#2386
HAVE_AVX2, HAVE_SSE3 and HAVE_SSE4_1 were never defined if CPU
architecture doesn't match the (86*|x86_64*|amd64*) condition.
Change-Id: If0c3128f9768f95c1f5f955db242e71c81384c6c
This change adds a check whether compiler supports some SIMD
(Single Instruction, Multiple Data) instructions. It is enabled
by default, and can be disabled by configure option --disable-simd.
The check macro is based on the AX_EXT from autoconf-archive:
www.gnu.org/software/autoconf-archive/ax_ext.html
And depends on the ax_check_compile_flag macro:
www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html
Currently only the following SIMD extensions are being checked:
AVX2, SSE3, SSE4.1, but adding others is also possible. All found
extensions are being defined in the 'config.h' header.
Change-Id: Idf8fff984bd936a75c7c307338df88ba4b005817
Even when removing AC_CONFIG_MACRO_DIR aclocal insisted that it
needs to have a m4 directory. Make it happy by providing one. As git
is not tracking directories I needed to add a dummy file.
Harald Welte
Vadim Yanitskiy