[Spice-devel] [PATCH spice-common] quic: Remove some too strict asserts in hot paths

[Frediano Ziglio]

Some assert in the code are doing some paranoid test and in code
paths quite hot.
The encoding time is reduced by 30-50% while the decoding time
is reduced by a 20-30%.

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 common/quic.c             | 20 ++++++++++++++------
 common/quic_family_tmpl.c |  4 +++-
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/common/quic.c b/common/quic.c
index 12e9b0b..c9c9df4 100644
--- a/common/quic.c
+++ b/common/quic.c
@@ -409,8 +409,10 @@ static inline void encode(Encoder *encoder, unsigned int word, unsigned int len)
 {
     int delta;
 
-    spice_assert(len > 0 && len < 32);
-    spice_assert(!(word & ~bppmask[len]));
+    if (spice_extra_checks) {
+        spice_assert(len > 0 && len < 32);
+        spice_assert(!(word & ~bppmask[len]));
+    }
     if ((delta = ((int)encoder->io_available_bits - len)) >= 0) {
         encoder->io_available_bits = delta;
         encoder->io_word |= word << encoder->io_available_bits;
@@ -422,8 +424,10 @@ static inline void encode(Encoder *encoder, unsigned int word, unsigned int len)
     encoder->io_available_bits = 32 - delta;
     encoder->io_word = word << encoder->io_available_bits;
 
-    spice_assert(encoder->io_available_bits < 32);
-    spice_assert((encoder->io_word & bppmask[encoder->io_available_bits]) == 0);
+    if (spice_extra_checks) {
+        spice_assert(encoder->io_available_bits < 32);
+        spice_assert((encoder->io_word & bppmask[encoder->io_available_bits]) == 0);
+    }
 }
 
 static inline void encode_32(Encoder *encoder, unsigned int word)
@@ -456,7 +460,9 @@ static inline void read_io_word(Encoder *encoder)
         __read_io_word_ptr(encoder); //disable inline optimizations
         return;
     }
-    spice_assert(encoder->io_now < encoder->io_end);
+    if (spice_extra_checks) {
+        spice_assert(encoder->io_now < encoder->io_end);
+    }
     encoder->io_next_word = GUINT32_FROM_LE(*(encoder->io_now++));
 }
 
@@ -464,7 +470,9 @@ static inline void decode_eatbits(Encoder *encoder, int len)
 {
     int delta;
 
-    spice_assert(len > 0 && len < 32);
+    if (spice_extra_checks) {
+        spice_assert(len > 0 && len < 32);
+    }
     encoder->io_word <<= len;
 
     if ((delta = ((int)encoder->io_available_bits - len)) >= 0) {
diff --git a/common/quic_family_tmpl.c b/common/quic_family_tmpl.c
index 9450f44..cda15bd 100644
--- a/common/quic_family_tmpl.c
+++ b/common/quic_family_tmpl.c
@@ -105,7 +105,9 @@ static void FNAME(update_model)(CommonState *state, s_bucket * const bucket,
 
 static s_bucket *FNAME(find_bucket)(Channel *channel, const unsigned int val)
 {
-    spice_assert(val < (0x1U << BPC));
+    if (spice_extra_checks) {
+        spice_assert(val < (0x1U << BPC));
+    }
 
     return channel->_buckets_ptrs[val];
 }
-- 
2.17.0