Commit Graph

10 Commits

Author SHA1 Message Date
Richard Henderson d9911d14e0 cutils: Rewrite x86 buffer zero checking
Handle alignment of buffers, so that the vector paths
can be used more often.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1473800239-13841-1-git-send-email-rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-14 12:25:14 +02:00
Richard Henderson 083d012a38 cutils: Add generic prefetch
There's no real knowledge of the cacheline size,
just prefetching one loop ahead.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1472496380-19706-7-git-send-email-rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-13 19:13:32 +02:00
Paolo Bonzini 86444f084b cutils: Add SSE4 version
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-13 19:13:32 +02:00
Richard Henderson efad668245 cutils: Add test for buffer_is_zero
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1472496380-19706-6-git-send-email-rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-13 19:13:32 +02:00
Richard Henderson 43ff5e01ec cutils: Remove ppc buffer zero checking
For ppc64le, gcc6 does extremely poorly with the Altivec code.
Moreover, on POWER7 and POWER8, a hand-optimized Altivec version
turns out to be no faster than the revised integer version, and
therefore not worth the effort.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-13 19:13:32 +02:00
Richard Henderson 2250d3a293 cutils: Remove aarch64 buffer zero checking
The revised integer version is 4 times faster than the neon version
on an AppliedMicro Mustang.  Even with hand scheduling and additional
unrolling I cannot make any neon version run as fast as the integer.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-13 19:13:31 +02:00
Richard Henderson 5e33a87222 cutils: Rearrange buffer_is_zero acceleration
Allow selection of several acceleration functions
based on the size and alignment of the buffer.
Do not require ifunc support for AVX2 acceleration.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1472496380-19706-5-git-send-email-rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-13 19:13:30 +02:00
Richard Henderson a1febc4950 cutils: Export only buffer_is_zero
Since the two users don't make use of the returned offset,
beyond ensuring that the entire buffer is zero, consider the
can_use_buffer_find_nonzero_offset and buffer_find_nonzero_offset
functions internal.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1472496380-19706-4-git-send-email-rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-13 19:09:45 +02:00
Richard Henderson 8c70c1b0c7 cutils: Remove SPLAT macro
This is unused and complicates the vector interface.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1472496380-19706-3-git-send-email-rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-13 19:09:45 +02:00
Richard Henderson 88ca8e80de cutils: Move buffer_is_zero and subroutines to a new file
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1472496380-19706-2-git-send-email-rth@twiddle.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-13 19:09:45 +02:00