On Mon, Feb 25, 2019 at 11:19 PM Ard Biesheuvel <ard.biesheu...@linaro.org> wrote: > > On Tue, 26 Feb 2019 at 05:03, <ndesaulni...@google.com> wrote: > > > > Clang warns: vector initializers are not compatible with NEON intrinsics > > in big endian mode [-Wnonportable-vector-initialization] > > > > While this is usually the case, it's not an issue for this case since > > we're initializing the uint8x16_t (16x uint8_t's) with the same value. > > > > Instead, use vdupq_n_u8 which both compilers lower into a single movi > > instruction: https://godbolt.org/z/vBrgzt > > > > This avoids the static storage for a constant value. > > > > Link: https://github.com/ClangBuiltLinux/linux/issues/214 > > Suggested-by: Nathan Chancellor <natechancel...@gmail.com> > > Signed-off-by: Nick Desaulniers <ndesaulni...@google.com> > > Much better, thanks, > > Did you double check that the intrinsic exists on 32-bit ARM as well? > I assume it does, but please make sure if you haven't yet.
Thanks for the review! Looking through Clang's generated arm_neon.h, vdupq_n_u8 seems to have 2 definitions predicated on __LITTLE_ENDIAN__ (not __arch64__ or __ARM_ARCH >= 8 like some of the other types and functions). So NEON got some additions in v8? Is there a doc that lists them? http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0491g/BABDBBJB.html is where I found vdupq_n_u8, but it doesn't seem to mention compatibility (so I assume it's been around since the introduction of NEON?). -- Thanks, ~Nick Desaulniers