Add a fast path to IndexOfQuoteOrAnyControlOrBackSlash

[EgorBo]

Validate the theory we came up with @tannergooding that we mostly find " character within first 16 bytes in this function (and the span is most of the time is bigger than 16 bytes) - e.g. the end of a property name

This doesn't replace #126678, just special cases for JSON where we indeed can assume something is usually found early.

Benchmark - 10-13% improvement on Cobalt100

arm64 codegen:

; Assembly listing for method JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlashG_M1629_IG01: stp fp, lr,[sp, #-0x20]!str x19,[sp, #0x18]mov fp,spG_M1629_IG02:cmp w1, #16 blt G_M1629_IG07G_M1629_IG03: ldr q16,[x0] movi v17.16b, #0x20 cmhi v17.16b, v17.16b, v16.16b movi v18.16b, #0x22 cmeq v18.16b, v16.16b, v18.16b orr v17.16b, v17.16b, v18.16b movi v18.16b, #0x5C cmeq v16.16b, v16.16b, v18.16b orr v16.16b, v17.16b, v16.16b shrn v16.8b, v16.8h, #4 umov x19, v16.d[0] cbnz x19, G_M1629_IG05add x0, x0, #16sub w1, w1, #16 movz x2, #0x67F0 // code for JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlash_Fallback(System.ReadOnlySpan`1[byte]):int movk x2, #0xC4E4LSL #16 movk x2, #0x7FFBLSL #32 ldr x2,[x2] blr x2add w1, w0, #16cmp w0, #0 csel w0, w1, w0, geG_M1629_IG04: ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20ret lrG_M1629_IG05: rbit x0, x19 clz x0, x0 asr w0, w0, #2G_M1629_IG06:  ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20ret lrG_M1629_IG07: movz x2, #0x67F0 // code for JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlash_Fallback(System.ReadOnlySpan`1[byte]):int movk x2, #0xC4E4LSL #16 movk x2, #0x7FFBLSL #32 ldr x2,[x2]G_M1629_IG08: ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20 br x2

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Tagging subscribers to this area: @dotnet/area-system-text-json
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[Copilot]

Pull request overview

Adds a SIMD fast-path to JsonReaderHelper.IndexOfQuoteOrAnyControlOrBackSlash to quickly detect " / \ / control characters by scanning the first 16 bytes before falling back to SearchValues<byte>-based searching.

Changes:

• Introduces a Vector128<byte>-based first-16-bytes scan for quote/backslash/control bytes.
• Adds an ARM64-specific mask extraction path using AdvSimd plus BitOperations.TrailingZeroCount.
• Moves the existing IndexOfAny(SearchValues<byte>) implementation into a non-inlined fallback helper.

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm -profiler

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[EgorBo]

@tannergooding I decided to implement the idea we discussed yesterday, I think your PR makes sense to check in too.
10-13% improvements on cloud arm (Cobalt100, Graviton4).

I couldn't detect more improvements from extending 16 bytes to 32 bytes so decided to keep as is. The fallback doesn't show up in the traces.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 3 comments.

[EgorBo]

@tannergooding do we need anything else here? I am cooking a PR to intrinsify IndexOfWhereAllBitsSet in JIT atm, so if it goes well, I'll replace this code with that

[tannergooding]

This LGTM to me as a fast path optimization. We can cleanup more as JIT optimizations come online and if we improve SearchValues so that it can be used directly after the appropriate slice occurs.

We probably want weigh-in from @eiriktsarpalis as well to ensure that 16 is the "right" size and not just a size that's optimal for this particular first party scenario (also cc. @jeffhandley as an fyi).

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[tannergooding]

Given we're expecting a match within the first vector, is this "better" than:

intindex=Vector128.IndexOfWhereAllBitsSet(cmp);if(index>=0){returnindex;}

I'd imagine its generating an extra test/extract for a case we presume is unlikely.

[EgorBo]

I can test with the both options. I think last time I checked cmp != Vector128<byte>.Zero didn't add overhead, but it might reduce it if there is no match in the first vector

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm -profiler

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[EgorBo]

Seems like after #126678 this PR no longer produces clear wins (suprisingly). It seems slow EMSB was the problem. Closing.

[EgorBo]

Validate the theory we came up with @tannergooding that we mostly find " character within first 16 bytes in this function (and the span is most of the time is bigger than 16 bytes) - e.g. the end of a property name

This doesn't replace #126678, just special cases for JSON where we indeed can assume something is usually found early.

Benchmark - 10-13% improvement on Cobalt100

arm64 codegen:

; Assembly listing for method JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlashG_M1629_IG01: stp fp, lr,[sp, #-0x20]!str x19,[sp, #0x18]mov fp,spG_M1629_IG02:cmp w1, #16 blt G_M1629_IG07G_M1629_IG03: ldr q16,[x0] movi v17.16b, #0x20 cmhi v17.16b, v17.16b, v16.16b movi v18.16b, #0x22 cmeq v18.16b, v16.16b, v18.16b orr v17.16b, v17.16b, v18.16b movi v18.16b, #0x5C cmeq v16.16b, v16.16b, v18.16b orr v16.16b, v17.16b, v16.16b shrn v16.8b, v16.8h, #4 umov x19, v16.d[0] cbnz x19, G_M1629_IG05add x0, x0, #16sub w1, w1, #16 movz x2, #0x67F0 // code for JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlash_Fallback(System.ReadOnlySpan`1[byte]):int movk x2, #0xC4E4LSL #16 movk x2, #0x7FFBLSL #32 ldr x2,[x2] blr x2add w1, w0, #16cmp w0, #0 csel w0, w1, w0, geG_M1629_IG04: ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20ret lrG_M1629_IG05: rbit x0, x19 clz x0, x0 asr w0, w0, #2G_M1629_IG06:  ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20ret lrG_M1629_IG07: movz x2, #0x67F0 // code for JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlash_Fallback(System.ReadOnlySpan`1[byte]):int movk x2, #0xC4E4LSL #16 movk x2, #0x7FFBLSL #32 ldr x2,[x2]G_M1629_IG08: ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20 br x2

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/area-system-text-json
See info in area-owners.md if you want to be subscribed.

[Copilot]

Pull request overview

Adds a SIMD fast-path to JsonReaderHelper.IndexOfQuoteOrAnyControlOrBackSlash to quickly detect " / \ / control characters by scanning the first 16 bytes before falling back to SearchValues<byte>-based searching.

Changes:

• Introduces a Vector128<byte>-based first-16-bytes scan for quote/backslash/control bytes.
• Adds an ARM64-specific mask extraction path using AdvSimd plus BitOperations.TrailingZeroCount.
• Moves the existing IndexOfAny(SearchValues<byte>) implementation into a non-inlined fallback helper.

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm -profiler

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[EgorBo]

@tannergooding I decided to implement the idea we discussed yesterday, I think your PR makes sense to check in too.
10-13% improvements on cloud arm (Cobalt100, Graviton4).

I couldn't detect more improvements from extending 16 bytes to 32 bytes so decided to keep as is. The fallback doesn't show up in the traces.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 3 comments.

[EgorBo]

@tannergooding do we need anything else here? I am cooking a PR to intrinsify IndexOfWhereAllBitsSet in JIT atm, so if it goes well, I'll replace this code with that

[tannergooding]

This LGTM to me as a fast path optimization. We can cleanup more as JIT optimizations come online and if we improve SearchValues so that it can be used directly after the appropriate slice occurs.

We probably want weigh-in from @eiriktsarpalis as well to ensure that 16 is the "right" size and not just a size that's optimal for this particular first party scenario (also cc. @jeffhandley as an fyi).

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[tannergooding]

Given we're expecting a match within the first vector, is this "better" than:

intindex=Vector128.IndexOfWhereAllBitsSet(cmp);if(index>=0){returnindex;}

I'd imagine its generating an extra test/extract for a case we presume is unlikely.

[EgorBo]

I can test with the both options. I think last time I checked cmp != Vector128<byte>.Zero didn't add overhead, but it might reduce it if there is no match in the first vector

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm -profiler

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[EgorBo]

Seems like after #126678 this PR no longer produces clear wins (suprisingly). It seems slow EMSB was the problem. Closing.

[EgorBo]

Validate the theory we came up with @tannergooding that we mostly find " character within first 16 bytes in this function (and the span is most of the time is bigger than 16 bytes) - e.g. the end of a property name

This doesn't replace #126678, just special cases for JSON where we indeed can assume something is usually found early.

Benchmark - 10-13% improvement on Cobalt100

arm64 codegen:

; Assembly listing for method JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlashG_M1629_IG01: stp fp, lr,[sp, #-0x20]!str x19,[sp, #0x18]mov fp,spG_M1629_IG02:cmp w1, #16 blt G_M1629_IG07G_M1629_IG03: ldr q16,[x0] movi v17.16b, #0x20 cmhi v17.16b, v17.16b, v16.16b movi v18.16b, #0x22 cmeq v18.16b, v16.16b, v18.16b orr v17.16b, v17.16b, v18.16b movi v18.16b, #0x5C cmeq v16.16b, v16.16b, v18.16b orr v16.16b, v17.16b, v16.16b shrn v16.8b, v16.8h, #4 umov x19, v16.d[0] cbnz x19, G_M1629_IG05add x0, x0, #16sub w1, w1, #16 movz x2, #0x67F0 // code for JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlash_Fallback(System.ReadOnlySpan`1[byte]):int movk x2, #0xC4E4LSL #16 movk x2, #0x7FFBLSL #32 ldr x2,[x2] blr x2add w1, w0, #16cmp w0, #0 csel w0, w1, w0, geG_M1629_IG04: ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20ret lrG_M1629_IG05: rbit x0, x19 clz x0, x0 asr w0, w0, #2G_M1629_IG06:  ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20ret lrG_M1629_IG07: movz x2, #0x67F0 // code for JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlash_Fallback(System.ReadOnlySpan`1[byte]):int movk x2, #0xC4E4LSL #16 movk x2, #0x7FFBLSL #32 ldr x2,[x2]G_M1629_IG08: ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20 br x2

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/area-system-text-json
See info in area-owners.md if you want to be subscribed.

[Copilot]

Pull request overview

Adds a SIMD fast-path to JsonReaderHelper.IndexOfQuoteOrAnyControlOrBackSlash to quickly detect " / \ / control characters by scanning the first 16 bytes before falling back to SearchValues<byte>-based searching.

Changes:

• Introduces a Vector128<byte>-based first-16-bytes scan for quote/backslash/control bytes.
• Adds an ARM64-specific mask extraction path using AdvSimd plus BitOperations.TrailingZeroCount.
• Moves the existing IndexOfAny(SearchValues<byte>) implementation into a non-inlined fallback helper.

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm -profiler

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[EgorBo]

@tannergooding I decided to implement the idea we discussed yesterday, I think your PR makes sense to check in too.
10-13% improvements on cloud arm (Cobalt100, Graviton4).

I couldn't detect more improvements from extending 16 bytes to 32 bytes so decided to keep as is. The fallback doesn't show up in the traces.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 3 comments.

[EgorBo]

@tannergooding do we need anything else here? I am cooking a PR to intrinsify IndexOfWhereAllBitsSet in JIT atm, so if it goes well, I'll replace this code with that

[tannergooding]

This LGTM to me as a fast path optimization. We can cleanup more as JIT optimizations come online and if we improve SearchValues so that it can be used directly after the appropriate slice occurs.

We probably want weigh-in from @eiriktsarpalis as well to ensure that 16 is the "right" size and not just a size that's optimal for this particular first party scenario (also cc. @jeffhandley as an fyi).

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[tannergooding]

Given we're expecting a match within the first vector, is this "better" than:

intindex=Vector128.IndexOfWhereAllBitsSet(cmp);if(index>=0){returnindex;}

I'd imagine its generating an extra test/extract for a case we presume is unlikely.

[EgorBo]

I can test with the both options. I think last time I checked cmp != Vector128<byte>.Zero didn't add overhead, but it might reduce it if there is no match in the first vector

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm -profiler

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[EgorBo]

Seems like after #126678 this PR no longer produces clear wins (suprisingly). It seems slow EMSB was the problem. Closing.

[EgorBo]

Validate the theory we came up with @tannergooding that we mostly find " character within first 16 bytes in this function (and the span is most of the time is bigger than 16 bytes) - e.g. the end of a property name

This doesn't replace #126678, just special cases for JSON where we indeed can assume something is usually found early.

Benchmark - 10-13% improvement on Cobalt100

arm64 codegen:

; Assembly listing for method JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlashG_M1629_IG01: stp fp, lr,[sp, #-0x20]!str x19,[sp, #0x18]mov fp,spG_M1629_IG02:cmp w1, #16 blt G_M1629_IG07G_M1629_IG03: ldr q16,[x0] movi v17.16b, #0x20 cmhi v17.16b, v17.16b, v16.16b movi v18.16b, #0x22 cmeq v18.16b, v16.16b, v18.16b orr v17.16b, v17.16b, v18.16b movi v18.16b, #0x5C cmeq v16.16b, v16.16b, v18.16b orr v16.16b, v17.16b, v16.16b shrn v16.8b, v16.8h, #4 umov x19, v16.d[0] cbnz x19, G_M1629_IG05add x0, x0, #16sub w1, w1, #16 movz x2, #0x67F0 // code for JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlash_Fallback(System.ReadOnlySpan`1[byte]):int movk x2, #0xC4E4LSL #16 movk x2, #0x7FFBLSL #32 ldr x2,[x2] blr x2add w1, w0, #16cmp w0, #0 csel w0, w1, w0, geG_M1629_IG04: ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20ret lrG_M1629_IG05: rbit x0, x19 clz x0, x0 asr w0, w0, #2G_M1629_IG06:  ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20ret lrG_M1629_IG07: movz x2, #0x67F0 // code for JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlash_Fallback(System.ReadOnlySpan`1[byte]):int movk x2, #0xC4E4LSL #16 movk x2, #0x7FFBLSL #32 ldr x2,[x2]G_M1629_IG08: ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20 br x2

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/area-system-text-json
See info in area-owners.md if you want to be subscribed.

[Copilot]

Pull request overview

Adds a SIMD fast-path to JsonReaderHelper.IndexOfQuoteOrAnyControlOrBackSlash to quickly detect " / \ / control characters by scanning the first 16 bytes before falling back to SearchValues<byte>-based searching.

Changes:

• Introduces a Vector128<byte>-based first-16-bytes scan for quote/backslash/control bytes.
• Adds an ARM64-specific mask extraction path using AdvSimd plus BitOperations.TrailingZeroCount.
• Moves the existing IndexOfAny(SearchValues<byte>) implementation into a non-inlined fallback helper.

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm -profiler

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[EgorBo]

@tannergooding I decided to implement the idea we discussed yesterday, I think your PR makes sense to check in too.
10-13% improvements on cloud arm (Cobalt100, Graviton4).

I couldn't detect more improvements from extending 16 bytes to 32 bytes so decided to keep as is. The fallback doesn't show up in the traces.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 3 comments.

[EgorBo]

@tannergooding do we need anything else here? I am cooking a PR to intrinsify IndexOfWhereAllBitsSet in JIT atm, so if it goes well, I'll replace this code with that

[tannergooding]

This LGTM to me as a fast path optimization. We can cleanup more as JIT optimizations come online and if we improve SearchValues so that it can be used directly after the appropriate slice occurs.

We probably want weigh-in from @eiriktsarpalis as well to ensure that 16 is the "right" size and not just a size that's optimal for this particular first party scenario (also cc. @jeffhandley as an fyi).

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[tannergooding]

Given we're expecting a match within the first vector, is this "better" than:

intindex=Vector128.IndexOfWhereAllBitsSet(cmp);if(index>=0){returnindex;}

I'd imagine its generating an extra test/extract for a case we presume is unlikely.

[EgorBo]

I can test with the both options. I think last time I checked cmp != Vector128<byte>.Zero didn't add overhead, but it might reduce it if there is no match in the first vector

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm -profiler

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[EgorBo]

Seems like after #126678 this PR no longer produces clear wins (suprisingly). It seems slow EMSB was the problem. Closing.

[EgorBo]

Validate the theory we came up with @tannergooding that we mostly find " character within first 16 bytes in this function (and the span is most of the time is bigger than 16 bytes) - e.g. the end of a property name

This doesn't replace #126678, just special cases for JSON where we indeed can assume something is usually found early.

Benchmark - 10-13% improvement on Cobalt100

arm64 codegen:

; Assembly listing for method JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlashG_M1629_IG01: stp fp, lr,[sp, #-0x20]!str x19,[sp, #0x18]mov fp,spG_M1629_IG02:cmp w1, #16 blt G_M1629_IG07G_M1629_IG03: ldr q16,[x0] movi v17.16b, #0x20 cmhi v17.16b, v17.16b, v16.16b movi v18.16b, #0x22 cmeq v18.16b, v16.16b, v18.16b orr v17.16b, v17.16b, v18.16b movi v18.16b, #0x5C cmeq v16.16b, v16.16b, v18.16b orr v16.16b, v17.16b, v16.16b shrn v16.8b, v16.8h, #4 umov x19, v16.d[0] cbnz x19, G_M1629_IG05add x0, x0, #16sub w1, w1, #16 movz x2, #0x67F0 // code for JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlash_Fallback(System.ReadOnlySpan`1[byte]):int movk x2, #0xC4E4LSL #16 movk x2, #0x7FFBLSL #32 ldr x2,[x2] blr x2add w1, w0, #16cmp w0, #0 csel w0, w1, w0, geG_M1629_IG04: ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20ret lrG_M1629_IG05: rbit x0, x19 clz x0, x0 asr w0, w0, #2G_M1629_IG06:  ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20ret lrG_M1629_IG07: movz x2, #0x67F0 // code for JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlash_Fallback(System.ReadOnlySpan`1[byte]):int movk x2, #0xC4E4LSL #16 movk x2, #0x7FFBLSL #32 ldr x2,[x2]G_M1629_IG08: ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20 br x2

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/area-system-text-json
See info in area-owners.md if you want to be subscribed.

[Copilot]

Pull request overview

Adds a SIMD fast-path to JsonReaderHelper.IndexOfQuoteOrAnyControlOrBackSlash to quickly detect " / \ / control characters by scanning the first 16 bytes before falling back to SearchValues<byte>-based searching.

Changes:

• Introduces a Vector128<byte>-based first-16-bytes scan for quote/backslash/control bytes.
• Adds an ARM64-specific mask extraction path using AdvSimd plus BitOperations.TrailingZeroCount.
• Moves the existing IndexOfAny(SearchValues<byte>) implementation into a non-inlined fallback helper.

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm -profiler

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[EgorBo]

@tannergooding I decided to implement the idea we discussed yesterday, I think your PR makes sense to check in too.
10-13% improvements on cloud arm (Cobalt100, Graviton4).

I couldn't detect more improvements from extending 16 bytes to 32 bytes so decided to keep as is. The fallback doesn't show up in the traces.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 3 comments.

[EgorBo]

@tannergooding do we need anything else here? I am cooking a PR to intrinsify IndexOfWhereAllBitsSet in JIT atm, so if it goes well, I'll replace this code with that

[tannergooding]

This LGTM to me as a fast path optimization. We can cleanup more as JIT optimizations come online and if we improve SearchValues so that it can be used directly after the appropriate slice occurs.

We probably want weigh-in from @eiriktsarpalis as well to ensure that 16 is the "right" size and not just a size that's optimal for this particular first party scenario (also cc. @jeffhandley as an fyi).

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[tannergooding]

Given we're expecting a match within the first vector, is this "better" than:

intindex=Vector128.IndexOfWhereAllBitsSet(cmp);if(index>=0){returnindex;}

I'd imagine its generating an extra test/extract for a case we presume is unlikely.

[EgorBo]

I can test with the both options. I think last time I checked cmp != Vector128<byte>.Zero didn't add overhead, but it might reduce it if there is no match in the first vector

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm -profiler

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[EgorBo]

Seems like after #126678 this PR no longer produces clear wins (suprisingly). It seems slow EMSB was the problem. Closing.

[EgorBo]

Validate the theory we came up with @tannergooding that we mostly find " character within first 16 bytes in this function (and the span is most of the time is bigger than 16 bytes) - e.g. the end of a property name

This doesn't replace #126678, just special cases for JSON where we indeed can assume something is usually found early.

Benchmark - 10-13% improvement on Cobalt100

arm64 codegen:

; Assembly listing for method JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlashG_M1629_IG01: stp fp, lr,[sp, #-0x20]!str x19,[sp, #0x18]mov fp,spG_M1629_IG02:cmp w1, #16 blt G_M1629_IG07G_M1629_IG03: ldr q16,[x0] movi v17.16b, #0x20 cmhi v17.16b, v17.16b, v16.16b movi v18.16b, #0x22 cmeq v18.16b, v16.16b, v18.16b orr v17.16b, v17.16b, v18.16b movi v18.16b, #0x5C cmeq v16.16b, v16.16b, v18.16b orr v16.16b, v17.16b, v16.16b shrn v16.8b, v16.8h, #4 umov x19, v16.d[0] cbnz x19, G_M1629_IG05add x0, x0, #16sub w1, w1, #16 movz x2, #0x67F0 // code for JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlash_Fallback(System.ReadOnlySpan`1[byte]):int movk x2, #0xC4E4LSL #16 movk x2, #0x7FFBLSL #32 ldr x2,[x2] blr x2add w1, w0, #16cmp w0, #0 csel w0, w1, w0, geG_M1629_IG04: ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20ret lrG_M1629_IG05: rbit x0, x19 clz x0, x0 asr w0, w0, #2G_M1629_IG06:  ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20ret lrG_M1629_IG07: movz x2, #0x67F0 // code for JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlash_Fallback(System.ReadOnlySpan`1[byte]):int movk x2, #0xC4E4LSL #16 movk x2, #0x7FFBLSL #32 ldr x2,[x2]G_M1629_IG08: ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20 br x2

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/area-system-text-json
See info in area-owners.md if you want to be subscribed.

[Copilot]

Pull request overview

Adds a SIMD fast-path to JsonReaderHelper.IndexOfQuoteOrAnyControlOrBackSlash to quickly detect " / \ / control characters by scanning the first 16 bytes before falling back to SearchValues<byte>-based searching.

Changes:

• Introduces a Vector128<byte>-based first-16-bytes scan for quote/backslash/control bytes.
• Adds an ARM64-specific mask extraction path using AdvSimd plus BitOperations.TrailingZeroCount.
• Moves the existing IndexOfAny(SearchValues<byte>) implementation into a non-inlined fallback helper.

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm -profiler

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[EgorBo]

@tannergooding I decided to implement the idea we discussed yesterday, I think your PR makes sense to check in too.
10-13% improvements on cloud arm (Cobalt100, Graviton4).

I couldn't detect more improvements from extending 16 bytes to 32 bytes so decided to keep as is. The fallback doesn't show up in the traces.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 3 comments.

[EgorBo]

@tannergooding do we need anything else here? I am cooking a PR to intrinsify IndexOfWhereAllBitsSet in JIT atm, so if it goes well, I'll replace this code with that

[tannergooding]

This LGTM to me as a fast path optimization. We can cleanup more as JIT optimizations come online and if we improve SearchValues so that it can be used directly after the appropriate slice occurs.

We probably want weigh-in from @eiriktsarpalis as well to ensure that 16 is the "right" size and not just a size that's optimal for this particular first party scenario (also cc. @jeffhandley as an fyi).

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[tannergooding]

Given we're expecting a match within the first vector, is this "better" than:

intindex=Vector128.IndexOfWhereAllBitsSet(cmp);if(index>=0){returnindex;}

I'd imagine its generating an extra test/extract for a case we presume is unlikely.

[EgorBo]

I can test with the both options. I think last time I checked cmp != Vector128<byte>.Zero didn't add overhead, but it might reduce it if there is no match in the first vector

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm -profiler

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[EgorBo]

Seems like after #126678 this PR no longer produces clear wins (suprisingly). It seems slow EMSB was the problem. Closing.

[EgorBo]

Validate the theory we came up with @tannergooding that we mostly find " character within first 16 bytes in this function (and the span is most of the time is bigger than 16 bytes) - e.g. the end of a property name

This doesn't replace #126678, just special cases for JSON where we indeed can assume something is usually found early.

Benchmark - 10-13% improvement on Cobalt100

arm64 codegen:

; Assembly listing for method JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlashG_M1629_IG01: stp fp, lr,[sp, #-0x20]!str x19,[sp, #0x18]mov fp,spG_M1629_IG02:cmp w1, #16 blt G_M1629_IG07G_M1629_IG03: ldr q16,[x0] movi v17.16b, #0x20 cmhi v17.16b, v17.16b, v16.16b movi v18.16b, #0x22 cmeq v18.16b, v16.16b, v18.16b orr v17.16b, v17.16b, v18.16b movi v18.16b, #0x5C cmeq v16.16b, v16.16b, v18.16b orr v16.16b, v17.16b, v16.16b shrn v16.8b, v16.8h, #4 umov x19, v16.d[0] cbnz x19, G_M1629_IG05add x0, x0, #16sub w1, w1, #16 movz x2, #0x67F0 // code for JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlash_Fallback(System.ReadOnlySpan`1[byte]):int movk x2, #0xC4E4LSL #16 movk x2, #0x7FFBLSL #32 ldr x2,[x2] blr x2add w1, w0, #16cmp w0, #0 csel w0, w1, w0, geG_M1629_IG04: ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20ret lrG_M1629_IG05: rbit x0, x19 clz x0, x0 asr w0, w0, #2G_M1629_IG06:  ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20ret lrG_M1629_IG07: movz x2, #0x67F0 // code for JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlash_Fallback(System.ReadOnlySpan`1[byte]):int movk x2, #0xC4E4LSL #16 movk x2, #0x7FFBLSL #32 ldr x2,[x2]G_M1629_IG08: ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20 br x2

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/area-system-text-json
See info in area-owners.md if you want to be subscribed.

[Copilot]

Pull request overview

Adds a SIMD fast-path to JsonReaderHelper.IndexOfQuoteOrAnyControlOrBackSlash to quickly detect " / \ / control characters by scanning the first 16 bytes before falling back to SearchValues<byte>-based searching.

Changes:

• Introduces a Vector128<byte>-based first-16-bytes scan for quote/backslash/control bytes.
• Adds an ARM64-specific mask extraction path using AdvSimd plus BitOperations.TrailingZeroCount.
• Moves the existing IndexOfAny(SearchValues<byte>) implementation into a non-inlined fallback helper.

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm -profiler

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[EgorBo]

@tannergooding I decided to implement the idea we discussed yesterday, I think your PR makes sense to check in too.
10-13% improvements on cloud arm (Cobalt100, Graviton4).

I couldn't detect more improvements from extending 16 bytes to 32 bytes so decided to keep as is. The fallback doesn't show up in the traces.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 3 comments.

[EgorBo]

@tannergooding do we need anything else here? I am cooking a PR to intrinsify IndexOfWhereAllBitsSet in JIT atm, so if it goes well, I'll replace this code with that

[tannergooding]

This LGTM to me as a fast path optimization. We can cleanup more as JIT optimizations come online and if we improve SearchValues so that it can be used directly after the appropriate slice occurs.

We probably want weigh-in from @eiriktsarpalis as well to ensure that 16 is the "right" size and not just a size that's optimal for this particular first party scenario (also cc. @jeffhandley as an fyi).

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[tannergooding]

Given we're expecting a match within the first vector, is this "better" than:

intindex=Vector128.IndexOfWhereAllBitsSet(cmp);if(index>=0){returnindex;}

I'd imagine its generating an extra test/extract for a case we presume is unlikely.

[EgorBo]

I can test with the both options. I think last time I checked cmp != Vector128<byte>.Zero didn't add overhead, but it might reduce it if there is no match in the first vector

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm -profiler

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[EgorBo]

Seems like after #126678 this PR no longer produces clear wins (suprisingly). It seems slow EMSB was the problem. Closing.

[EgorBo]

Validate the theory we came up with @tannergooding that we mostly find " character within first 16 bytes in this function (and the span is most of the time is bigger than 16 bytes) - e.g. the end of a property name

This doesn't replace #126678, just special cases for JSON where we indeed can assume something is usually found early.

Benchmark - 10-13% improvement on Cobalt100

arm64 codegen:

; Assembly listing for method JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlashG_M1629_IG01: stp fp, lr,[sp, #-0x20]!str x19,[sp, #0x18]mov fp,spG_M1629_IG02:cmp w1, #16 blt G_M1629_IG07G_M1629_IG03: ldr q16,[x0] movi v17.16b, #0x20 cmhi v17.16b, v17.16b, v16.16b movi v18.16b, #0x22 cmeq v18.16b, v16.16b, v18.16b orr v17.16b, v17.16b, v18.16b movi v18.16b, #0x5C cmeq v16.16b, v16.16b, v18.16b orr v16.16b, v17.16b, v16.16b shrn v16.8b, v16.8h, #4 umov x19, v16.d[0] cbnz x19, G_M1629_IG05add x0, x0, #16sub w1, w1, #16 movz x2, #0x67F0 // code for JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlash_Fallback(System.ReadOnlySpan`1[byte]):int movk x2, #0xC4E4LSL #16 movk x2, #0x7FFBLSL #32 ldr x2,[x2] blr x2add w1, w0, #16cmp w0, #0 csel w0, w1, w0, geG_M1629_IG04: ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20ret lrG_M1629_IG05: rbit x0, x19 clz x0, x0 asr w0, w0, #2G_M1629_IG06:  ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20ret lrG_M1629_IG07: movz x2, #0x67F0 // code for JsonReaderHelper:IndexOfQuoteOrAnyControlOrBackSlash_Fallback(System.ReadOnlySpan`1[byte]):int movk x2, #0xC4E4LSL #16 movk x2, #0x7FFBLSL #32 ldr x2,[x2]G_M1629_IG08: ldr x19,[sp, #0x18] ldp fp, lr,[sp], #0x20 br x2

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[Copilot]

Pull request overview

Adds a SIMD fast-path to JsonReaderHelper.IndexOfQuoteOrAnyControlOrBackSlash to quickly detect " / \ / control characters by scanning the first 16 bytes before falling back to SearchValues<byte>-based searching.

Changes:

• Introduces a Vector128<byte>-based first-16-bytes scan for quote/backslash/control bytes.
• Adds an ARM64-specific mask extraction path using AdvSimd plus BitOperations.TrailingZeroCount.
• Moves the existing IndexOfAny(SearchValues<byte>) implementation into a non-inlined fallback helper.

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm -profiler

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[EgorBo]

@tannergooding I decided to implement the idea we discussed yesterday, I think your PR makes sense to check in too.
10-13% improvements on cloud arm (Cobalt100, Graviton4).

I couldn't detect more improvements from extending 16 bytes to 32 bytes so decided to keep as is. The fallback doesn't show up in the traces.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 3 comments.

[EgorBo]

@tannergooding do we need anything else here? I am cooking a PR to intrinsify IndexOfWhereAllBitsSet in JIT atm, so if it goes well, I'll replace this code with that

[tannergooding]

This LGTM to me as a fast path optimization. We can cleanup more as JIT optimizations come online and if we improve SearchValues so that it can be used directly after the appropriate slice occurs.

We probably want weigh-in from @eiriktsarpalis as well to ensure that 16 is the "right" size and not just a size that's optimal for this particular first party scenario (also cc. @jeffhandley as an fyi).

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[tannergooding]

Given we're expecting a match within the first vector, is this "better" than:

intindex=Vector128.IndexOfWhereAllBitsSet(cmp);if(index>=0){returnindex;}

I'd imagine its generating an extra test/extract for a case we presume is unlikely.

[EgorBo]

I can test with the both options. I think last time I checked cmp != Vector128<byte>.Zero didn't add overhead, but it might reduce it if there is no match in the first vector

[EgorBo]

@EgorBot -linux_azure_arm -arm -linux_aws_arm -profiler

usingSystem.Text;usingSystem.Text.Json;usingBenchmarkDotNet.Attributes;usingBenchmarkDotNet.Running;BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);[MemoryDiagnoser]publicclassBenchmarks{// ── TokenSerialization fields ────────────────────────────────────────────privateList<object>_tokenObjects;[ThreadStatic]staticUtf8JsonWritert_writer;[ThreadStatic]staticMemoryStreamt_stream;[GlobalSetup]publicvoidSetup(){// TokenSerialization_tokenObjects=newList<object>(200);for(inti=0;i<200;i++){if(i%3==0)_tokenObjects.Add(GenerateRecordJson(1));else_tokenObjects.Add(newDictionary<string,object>{["seq"]=i,["label"]=$"item_{i}",["blob"]=newbyte[100]});}}privatestaticstringGenerateRecordJson(inttargetSizeKb=150){varsb=newStringBuilder(targetSizeKb*1024+512);sb.Append("{");sb.Append("\"TypeName\":\"product\",");sb.Append("\"CategoryCode\":1,");sb.Append("\"Label\":\"Product\",");sb.Append("\"IsAction\":false,");sb.Append("\"IsActionMember\":false,");sb.Append("\"IsTrackingEnabled\":true,");sb.Append("\"IsAvailableLocal\":true,");sb.Append("\"IsChildRecord\":false,");sb.Append("\"IsLinksEnabled\":true,");sb.Append("\"IsCustomRecord\":false,");sb.Append("\"PrimaryKeyField\":\"productid\",");sb.Append("\"PrimaryLabelField\":\"title\",");sb.Append("\"Fields\":[");inttargetBytes=targetSizeKb*1024;intfieldIndex=0;boolfirstField=true;while(sb.Length<targetBytes-512){if(!firstField)sb.Append(",");firstField=false;sb.Append("{");sb.Append($"\"TypeName\":\"field_{fieldIndex}\",");sb.Append($"\"InternalName\":\"Field_{fieldIndex}\",");sb.Append($"\"FieldType\":\"String\",");sb.Append($"\"Label\":\"Field {fieldIndex}\",");sb.Append($"\"MaxSize\":100,");sb.Append($"\"IsReadable\":true,");sb.Append($"\"IsCreatable\":true,");sb.Append($"\"IsUpdatable\":true,");sb.Append($"\"IsTrackingEnabled\":false,");sb.Append($"\"IsPrimaryKey\":false,");sb.Append($"\"IsVirtual\":false,");sb.Append($"\"Requirement\":\"None\"");sb.Append("}");fieldIndex++;}sb.Append("]");sb.Append("}");returnsb.ToString();}[Benchmark]publicvoidTokenSerialization(){varstream=t_stream??=newMemoryStream(64*1024);stream.Position=0;stream.SetLength(0);varwriter=t_writer;if(writer==null){writer=newUtf8JsonWriter(stream,newJsonWriterOptions{SkipValidation=true});t_writer=writer;}elsewriter.Reset(stream);writer.WriteStartObject();writer.WriteStartArray("Catalog");foreach(vartokenin_tokenObjects){if(tokenisstringstrToken){if(!string.IsNullOrEmpty(strToken))writer.WriteRawValue(strToken);}elseif(tokenisDictionary<string,object>dictToken){writer.WriteStartObject();foreach(varkvpindictToken){writer.WritePropertyName(kvp.Key);JsonSerializer.Serialize(writer,kvp.Value);}writer.WriteEndObject();}}writer.WriteEndArray();writer.WriteEndObject();writer.Flush();if(stream.Length==0)thrownewException("unreachable");}}

[EgorBo]

Seems like after #126678 this PR no longer produces clear wins (suprisingly). It seems slow EMSB was the problem. Closing.