diff options
author | Josh Haberman <jhaberman@gmail.com> | 2011-03-20 13:13:51 -0700 |
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committer | Josh Haberman <jhaberman@gmail.com> | 2011-03-20 13:13:51 -0700 |
commit | 8ef6873e0e14309a1715a252a650bab0ae1a33ef (patch) | |
tree | a9f81f9fa3ee24b923310cef964c1cbe1bf47a19 /src/upb_decoder_x64.asm | |
parent | 37e1c3102be15f1e57805e828993156e3492d764 (diff) |
upb_stream: all callbacks registered ahead-of-time.
This is a significant change to the upb_stream
protocol, and should hopefully be the last
significant change.
All callbacks are now registered ahead-of-time
instead of having delegated callbacks registered
at runtime, which makes it much easier to
aggressively optimize ahead-of-time (like with a
JIT).
Other impacts of this change:
- You no longer need to have loaded descriptor.proto
as a upb_def to load other descriptors! This means
the special-case code we used for bootstrapping is
no longer necessary, and we no longer need to link
the descriptor for descriptor.proto into upb.
- A client can now register any upb_value as what
will be delivered to their value callback, not
just a upb_fielddef*. This should allow for other
clients to get more bang out of the streaming
decoder.
This change unfortunately causes a bit of a performance
regression -- I think largely due to highly
suboptimal code that GCC generates when structs
are returned by value. See:
http://blog.reverberate.org/2011/03/19/when-a-compilers-slow-code-actually-bites-you/
On the other hand, once we have a JIT this should
no longer matter.
Performance numbers:
plain.parsestream_googlemessage1.upb_table: 374 -> 396 (5.88)
plain.parsestream_googlemessage2.upb_table: 616 -> 449 (-27.11)
plain.parsetostruct_googlemessage1.upb_table_byref: 268 -> 269 (0.37)
plain.parsetostruct_googlemessage1.upb_table_byval: 215 -> 204 (-5.12)
plain.parsetostruct_googlemessage2.upb_table_byref: 307 -> 281 (-8.47)
plain.parsetostruct_googlemessage2.upb_table_byval: 297 -> 272 (-8.42)
omitfp.parsestream_googlemessage1.upb_table: 423 -> 410 (-3.07)
omitfp.parsestream_googlemessage2.upb_table: 679 -> 483 (-28.87)
omitfp.parsetostruct_googlemessage1.upb_table_byref: 287 -> 282 (-1.74)
omitfp.parsetostruct_googlemessage1.upb_table_byval: 226 -> 219 (-3.10)
omitfp.parsetostruct_googlemessage2.upb_table_byref: 315 -> 298 (-5.40)
omitfp.parsetostruct_googlemessage2.upb_table_byval: 297 -> 287 (-3.37)
Diffstat (limited to 'src/upb_decoder_x64.asm')
-rw-r--r-- | src/upb_decoder_x64.asm | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/src/upb_decoder_x64.asm b/src/upb_decoder_x64.asm index 032ea86..c417644 100644 --- a/src/upb_decoder_x64.asm +++ b/src/upb_decoder_x64.asm @@ -34,8 +34,8 @@ SECTION .text %define BUF rbx ; const char *p, current buf position. %define END rbp ; const char *end, where the buf ends (either submsg end or buf end) %define STRING r12 ; unused -%define FIELDDEF r13 ; upb_fielddef *f, needs to be preserved across varint decoding call. -%define CALLBACK r14 +%define FVAL r13 ; upb_value fval, needs to be preserved across varint decoding call. +%define UNUSED r14 %define CLOSURE r15 ; Stack layout: *tableptr, uint32_t maxfield_times_8 @@ -57,10 +57,10 @@ SECTION .text ; path that goes into a tight loop if the encoding was packed). ; - check_6: the field is not a group or a message (or string, TODO) ; (this could be relaxed, but due to delegation it's a bit tricky). -; - if the value is a string, the entire string is available in +; - check_7: if the value is a string, the entire string is available in ; the buffer, and our cached string object can be recycled, and ; our string object already references the source buffer, so -; absolutely no refcount twiddling is required. (check_7) +; absolutely no refcount twiddling is required. %macro decode_and_dispatch_ 0 @@ -78,7 +78,7 @@ align 16 ; Decode a 1 or 2-byte varint -> eax. mov cl, byte [BUF] lea rdi, [BUF+1] - movzx rax, cl ; Need all of rax since we're doing a 64-bit lea later. + movzx eax, cl and eax, 0x7f test cl, cl jns .one_byte_tag ; Should be predictable if fields are in order. |