Optimize further the loading of 8 Latin 1 characters

This is important when AVX is enabled, which makes the VMOVQ load and
the VPMOVZXBW instruction be combined into a single VPMOVZXBW with
direct memory access. This is guaranteed to only read 8 bytes, so it's
safe even close to the end of a page. Clang and ICC do combine the
instructions like we want and I have filed a request for GCC to do so
too[1].

AVX was first introduced in 2011, so plenty of computers today would
benefit from this.

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87317

Change-Id: I8f261579aad648fdb4f0fffd1553e08e90df3171
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

0 files changed, 0 insertions, 0 deletions