g10/armor: optimize binary to radix64 conversion

* g10/armor.c (bintoasc): Change to read-only.
(initialize): Use const pointer for 'bintoasc'.
(armor_output_buf_as_radix64): New function for faster binary to
radix64 conversion.
(armor_filter): Use new conversion function.
--

This patch adds faster binary to radix64 conversion to speed up
armored encryption.

Benchmark results below, tested on Intel Core i7-4790K (turbo off).
Encrypted 2 GiB through pipe to ramfs file using AES128. Decrypt
ramfs file out through pipe to /dev/null.

before patch-set
----------------
               gpg process
armor:         user time    pipe transfer rate
 encrypt-aead:  13.8         140 MB/s
 decrypt-aead:  30.6         68 MB/s
 encrypt-cfb:   17.4         114 MB/s
 decrypt-cfb:   32.6         64 MB/s

after (decrypt+iobuf+crc+radix64 opt)
-------------------------------------
               gpg process
armor:         user time    pipe transfer rate
 encrypt-aead:  2.7          523 MB/s
 encrypt-cfb:   6.7          264 MB/s

Signed-off-by: Jussi Kivilinna <[email protected]>

0 files changed, 0 insertions, 0 deletions