From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp30.i.mail.ru (smtp30.i.mail.ru [94.100.177.90]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dev.tarantool.org (Postfix) with ESMTPS id 3CC024765E0 for ; Fri, 25 Dec 2020 16:02:00 +0300 (MSK) References: From: Leonid Vasiliev Message-ID: <8ed7e38f-acd6-16ec-94ba-934e6b268b04@tarantool.org> Date: Fri, 25 Dec 2020 16:01:54 +0300 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Tarantool-patches] [PATCH v5 2/2] base64: improve decoder performance List-Id: Tarantool development patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Sergey Nikiforov , tarantool-patches@dev.tarantool.org Cc: Vladislav Shpilevoy Hi! Thank you for the patch. LGTM. On 25.12.2020 13:41, Sergey Nikiforov wrote: > Unnecessary checks were removed from internal loops. > Benchmark shows that performance is now ~1.19 times higher > (release build, Intel Core I7-9700K, only one thread). > --- > third_party/base64.c | 35 ++++++++++++++++++++++++++--------- > 1 file changed, 26 insertions(+), 9 deletions(-) > > diff --git a/third_party/base64.c b/third_party/base64.c > index 3350a98ff..2b2b61ba4 100644 > --- a/third_party/base64.c > +++ b/third_party/base64.c > @@ -257,10 +257,10 @@ base64_decode_block(const char *in_base64, int in_len, > { > case step_a: > do { > - if (in_pos == in_end || out_pos >= out_end) > + if (in_pos >= in_end) > { > state->step = step_a; > - state->result = curr_byte; > + /* curr_byte is useless now. */ > return out_pos - out_bin; > } > fragment = base64_decode_value(*in_pos++); > @@ -268,7 +268,7 @@ base64_decode_block(const char *in_base64, int in_len, > curr_byte = (fragment & 0x03f) << 2; > case step_b: > do { > - if (in_pos == in_end || out_pos >= out_end) > + if (in_pos >= in_end) > { > state->step = step_b; > state->result = curr_byte; > @@ -276,14 +276,19 @@ base64_decode_block(const char *in_base64, int in_len, > } > fragment = base64_decode_value(*in_pos++); > } while (fragment < 0); > + if (out_pos >= out_end) > + { > + /* We are losing some data. */ > + state->step = step_b; > + state->result = curr_byte; > + return out_pos - out_bin; > + } > curr_byte |= (fragment & 0x030) >> 4; > *out_pos++ = curr_byte; > curr_byte = (fragment & 0x00f) << 4; > - if (out_pos < out_end) > - *out_pos = curr_byte; > case step_c: > do { > - if (in_pos == in_end || out_pos >= out_end) > + if (in_pos >= in_end) > { > state->step = step_c; > state->result = curr_byte; > @@ -291,14 +296,19 @@ base64_decode_block(const char *in_base64, int in_len, > } > fragment = base64_decode_value(*in_pos++); > } while (fragment < 0); > + if (out_pos >= out_end) > + { > + /* We are losing some data. */ > + state->step = step_c; > + state->result = curr_byte; > + return out_pos - out_bin; > + } > curr_byte |= (fragment & 0x03c) >> 2; > *out_pos++ = curr_byte; > curr_byte = (fragment & 0x003) << 6; > - if (out_pos < out_end) > - *out_pos = curr_byte; > case step_d: > do { > - if (in_pos == in_end || out_pos >= out_end) > + if (in_pos >= in_end) > { > state->step = step_d; > state->result = curr_byte; > @@ -306,6 +316,13 @@ base64_decode_block(const char *in_base64, int in_len, > } > fragment = base64_decode_value(*in_pos++); > } while (fragment < 0); > + if (out_pos >= out_end) > + { > + /* We are losing some data. */ > + state->step = step_d; > + state->result = curr_byte; > + return out_pos - out_bin; > + } > curr_byte |= (fragment & 0x03f); > *out_pos++ = curr_byte; > } >