apps/speed.c: add -aead flag.

Goal is to exercise AEAD ciphers in TLS-like sequence, i.e. 13-byte
AAD followed by payload. Update doc/man1/speed.pod accordingly.

[While we are at it, address even some styling and readability issues.]

Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6311)

1 files changed, 10 insertions, 4 deletions

diff --git a/doc/man1/speed.pod b/doc/man1/speed.pod
index 4f46fac..523da0d 100644
--- a/doc/man1/speed.pod
+++ b/doc/man1/speed.pod
@@ -16,6 +16,8 @@ B<openssl speed>
 [B<-rand file...>]
 [B<-writerand file>]
 [B<-primes num>]
+[B<-seconds num>]
+[B<-bytes num>]
 [B<algorithm...>]
 
 =head1 DESCRIPTION
@@ -42,12 +44,16 @@ for all available algorithms.
 
 =item B<-elapsed>
 
-Measure time in real time instead of CPU time. It can be useful when testing
-speed of hardware engines.
+When calculating operations- or bytes-per-second, use wall-clock time
+instead of CPU user time as divisor. It can be useful when testing speed
+of hardware engines.
 
 =item B<-evp algo>
 
 Use the specified cipher or message digest algorithm via the EVP interface.
+If B<algo> is an AEAD cipher, then you can pass <-aead> to benchmark a
+TLS-like sequence. And if B<algo> is a multi-buffer capable cipher, e.g.
+aes-128-cbc-hmac-sha1, then B<-mb> will time multi-buffer operation.
 
 =item B<-decrypt>
 
@@ -81,8 +87,8 @@ Run benchmarks on B<num>-byte buffers. Affects ciphers, digests and the CSPRNG.
 
 =item B<[zero or more test algorithms]>
 
-If any options are given, B<speed> tests those algorithms, otherwise all of
-the above are tested.
+If any options are given, B<speed> tests those algorithms, otherwise a
+pre-compiled grand selection is tested.
 
 =back