feat: Reduce the amount of llvm IR generated #1848

Marwes · 2020-07-03T10:03:53Z

There are several orthogonal commits here which could be removed if they aren't wanted.

In total this reduces the IR generated by ~5.5% (105103 / 111368 = 0.94374506142) in the twitter example of https://github.com/serde-rs/json-benchmark

Before

cargo llvm-lines  --bin json-benchmark --no-default-features --features lib-serde,file-twitter,performance | rg '(serde|TOTAL)' | head -31
    Updating crates.io index
   Compiling json-benchmark v0.0.1 (/home/markus/Code/json-benchmark)
    Finished dev [unoptimized + debuginfo] target(s) in 3.19s
  111368 (100%)  1640 (100%)  (TOTAL)
   13186 (11.8%)   43 (2.6%)  <serde_json::de::SeqAccess<R> as serde::de::SeqAccess>::next_element_seed
    9397 (8.4%)    15 (0.9%)  <&mut serde_json::de::Deserializer<R> as serde::de::Deserializer>::deserialize_struct
    5430 (4.9%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::User>::deserialize::__Visitor as serde::de::Visitor>::visit_map
    4267 (3.8%)    15 (0.9%)  <serde_json::de::MapAccess<R> as serde::de::MapAccess>::next_key_seed
    3939 (3.5%)    39 (2.4%)  <serde_json::ser::Compound<W,F> as serde::ser::SerializeMap>::serialize_value
    3262 (2.9%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::Status>::deserialize::__Visitor as serde::de::Visitor>::visit_map
    3151 (2.8%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::User>::deserialize::__Visitor as serde::de::Visitor>::visit_seq
    2722 (2.4%)     7 (0.4%)  <&mut serde_json::de::Deserializer<R> as serde::de::Deserializer>::deserialize_seq
    2353 (2.1%)    38 (2.3%)  <serde_json::de::MapAccess<R> as serde::de::MapAccess>::next_value_seed
    1947 (1.7%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::Status>::deserialize::__Visitor as serde::de::Visitor>::visit_seq
    1888 (1.7%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::Media>::deserialize::__Visitor as serde::de::Visitor>::visit_map
    1864 (1.7%)    15 (0.9%)  <serde_json::de::MapKey<R> as serde::de::Deserializer>::deserialize_any
    1789 (1.6%)     7 (0.4%)  <&mut serde_json::de::Deserializer<R> as serde::de::Deserializer>::deserialize_str
    1626 (1.5%)     6 (0.4%)  serde_json::de::Deserializer<R>::deserialize_number
    1557 (1.4%)    39 (2.4%)  serde::ser::SerializeMap::serialize_entry
    1422 (1.3%)     6 (0.4%)  serde::ser::Serializer::collect_seq
    1321 (1.2%)    10 (0.6%)  <&mut serde_json::de::Deserializer<R> as serde::de::Deserializer>::deserialize_option
    1291 (1.2%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::SearchMetadata>::deserialize::__Visitor as serde::de::Visitor>::visit_map
    1013 (0.9%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::Media>::deserialize::__Visitor as serde::de::Visitor>::visit_seq
     988 (0.9%)    28 (1.7%)  <serde::private::de::missing_field::MissingFieldDeserializer<E> as serde::de::Deserializer>::deserialize_any
     946 (0.8%)    38 (2.3%)  serde::private::de::missing_field
     867 (0.8%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::StatusEntities>::deserialize::__Visitor as serde::de::Visitor>::visit_map
     854 (0.8%)     1 (0.1%)  json_benchmark::copy::twitter::_::<impl serde::ser::Serialize for json_benchmark::copy::twitter::User>::serialize
     817 (0.7%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::UserMention>::deserialize::__Visitor as serde::de::Visitor>::visit_map
     777 (0.7%)     7 (0.4%)  <serde_json::ser::Compound<W,F> as serde::ser::SerializeSeq>::serialize_element
     769 (0.7%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::Url>::deserialize::__Visitor as serde::de::Visitor>::visit_map
     729 (0.7%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::SearchMetadata>::deserialize::__Visitor as serde::de::Visitor>::visit_seq
     716 (0.6%)    58 (3.5%)  <core::marker::PhantomData<T> as serde::de::DeserializeSeed>::deserialize
     637 (0.6%)     5 (0.3%)  <serde::de::impls::<impl serde::de::Deserialize for alloc::vec::Vec<T>>::deserialize::VecVisitor<T> as serde::de::Visitor>::visit_seq
     598 (0.5%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::Sizes>::deserialize::__Visitor as serde::de::Visitor>::visit_map

After

cargo llvm-lines  --bin json-benchmark --no-default-features --features lib-serde,file-twitter,performance | rg '(serde|TOTAL)' | head -31
    Updating crates.io index
   Compiling json-benchmark v0.0.1 (/home/markus/Code/json-benchmark)
    Finished dev [unoptimized + debuginfo] target(s) in 3.19s
  105103 (100%)  1681 (100%)  (TOTAL)
   13186 (12.5%)   43 (2.6%)  <serde_json::de::SeqAccess<R> as serde::de::SeqAccess>::next_element_seed
    9397 (8.9%)    15 (0.9%)  <&mut serde_json::de::Deserializer<R> as serde::de::Deserializer>::deserialize_struct
    4267 (4.1%)    15 (0.9%)  <serde_json::de::MapAccess<R> as serde::de::MapAccess>::next_key_seed
    3939 (3.7%)    39 (2.3%)  <serde_json::ser::Compound<W,F> as serde::ser::SerializeMap>::serialize_value
    3329 (3.2%)    38 (2.3%)  serde::private::de::next_non_duplicate_value
    2753 (2.6%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::User>::deserialize::__Visitor as serde::de::Visitor>::visit_seq
    2722 (2.6%)     7 (0.4%)  <&mut serde_json::de::Deserializer<R> as serde::de::Deserializer>::deserialize_seq
    2527 (2.4%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::User>::deserialize::__Visitor as serde::de::Visitor>::visit_map
    2353 (2.2%)    38 (2.3%)  <serde_json::de::MapAccess<R> as serde::de::MapAccess>::next_value_seed
    1864 (1.8%)    15 (0.9%)  <serde_json::de::MapKey<R> as serde::de::Deserializer>::deserialize_any
    1789 (1.7%)     7 (0.4%)  <&mut serde_json::de::Deserializer<R> as serde::de::Deserializer>::deserialize_str
    1687 (1.6%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::Status>::deserialize::__Visitor as serde::de::Visitor>::visit_seq
    1626 (1.5%)     6 (0.4%)  serde_json::de::Deserializer<R>::deserialize_number
    1557 (1.5%)    39 (2.3%)  serde::ser::SerializeMap::serialize_entry
    1534 (1.5%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::Status>::deserialize::__Visitor as serde::de::Visitor>::visit_map
    1521 (1.4%)    38 (2.3%)  serde::private::de::extract_field
    1422 (1.4%)     6 (0.4%)  serde::ser::Serializer::collect_seq
    1321 (1.3%)    10 (0.6%)  <&mut serde_json::de::Deserializer<R> as serde::de::Deserializer>::deserialize_option
     988 (0.9%)    28 (1.7%)  <serde::private::de::missing_field::MissingFieldDeserializer<E> as serde::de::Deserializer>::deserialize_any
     946 (0.9%)    38 (2.3%)  serde::private::de::missing_field
     938 (0.9%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::Media>::deserialize::__Visitor as serde::de::Visitor>::visit_map
     923 (0.9%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::Media>::deserialize::__Visitor as serde::de::Visitor>::visit_seq
     854 (0.8%)     1 (0.1%)  json_benchmark::copy::twitter::_::<impl serde::ser::Serialize for json_benchmark::copy::twitter::User>::serialize
     777 (0.7%)     7 (0.4%)  <serde_json::ser::Compound<W,F> as serde::ser::SerializeSeq>::serialize_element
     716 (0.7%)    58 (3.5%)  <core::marker::PhantomData<T> as serde::de::DeserializeSeed>::deserialize
     655 (0.6%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::SearchMetadata>::deserialize::__Visitor as serde::de::Visitor>::visit_map
     645 (0.6%)     1 (0.1%)  <json_benchmark::copy::twitter::_::<impl serde::de::Deserialize for json_benchmark::copy::twitter::SearchMetadata>::deserialize::__Visitor as serde::de::Visitor>::visit_seq
     637 (0.6%)     5 (0.3%)  <serde::de::impls::<impl serde::de::Deserialize for alloc::vec::Vec<T>>::deserialize::VecVisitor<T> as serde::de::Visitor>::visit_seq
     570 (0.5%)    38 (2.3%)  <serde_json::ser::Compound<W,F> as serde::ser::SerializeStruct>::serialize_field
     569 (0.5%)     1 (0.1%)  json_benchmark::copy::twitter::_::<impl serde::ser::Serialize for json_benchmark::copy::twitter::Status>::serialize

…r type

Marwes · 2021-01-04T17:53:17Z

Rebased and add a few more changes which totals up the improvement in my testing to 5.5% (up from 1.7%)

Markus Westerlind added 7 commits January 4, 2021 15:21

De-duplicate the field matching

d000d14

Hoist invalid_error errors to a common place

c1ed48a

refactor: Precompute the serialized length when possible

68d312e

Matching is cheaper than is_some

0abef88

refactor: Extract more of the field unpacking into a function

7a5d347

refactor: Extract the duplicate check into a function instantiated pe…

b57b83d

…r type

refactor: Merge the Err returns of (most) visit_map alternatives

3da157e

Marwes force-pushed the smaller_de branch from 944aaef to bd48aae Compare January 4, 2021 17:43

refactor: Factor out ignoring fields to a common function

c48166d

Marwes force-pushed the smaller_de branch from bd48aae to c48166d Compare January 4, 2021 17:45

Fix CI on 1.13

d28c394

indiv0 mentioned this pull request May 15, 2022

Improving Compile Times And/Or Add Pluggable Deserializable Types awslabs/aws-lambda-rust-runtime#481

Closed

dtolnay force-pushed the master branch from 58c82f1 to d208762 Compare September 3, 2022 04:16

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feat: Reduce the amount of llvm IR generated #1848

feat: Reduce the amount of llvm IR generated #1848

Marwes commented Jul 3, 2020 •

edited

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Marwes commented Jan 4, 2021

feat: Reduce the amount of llvm IR generated #1848

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feat: Reduce the amount of llvm IR generated #1848

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Marwes commented Jan 4, 2021

Marwes commented Jul 3, 2020 •

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