Add limited support for backtracking Regex single char loops to simplified code gen

[stephentoub]

In .NET 5, we added simpler compiled code gen for regexes that didn't entail backtracking (or that had only very constrained backtracking, such as a top-level alternation). In our corpus of ~90K regular expressions, that code generator is employed for ~40% of them. The primary purpose of adding that code generator initially was performance, as it was able to avoid lots of the expense that original code generator had, especially for simple regexes. However, with the source generator, it's much more valuable to use this code gen as the generated code is human-readable and really helps to understand how the regex is operating, is much more easily debugged, etc.

This change allows the simplified code gen to be used even if there are backtracking single-character loops in the regex, as long as those loops are in a top-level concatenation (or a simple grouping structure like a capture). This increases the percentage of expressions in our corpus that will use the simplified code gen to ~65%.

Once we have the simplified loop code gen, it's also a lot easier to add in vectorization of searching for the next location to back off to based on a literal that comes immediately after the loop (e.g. "abc.*def"). This adds support into both RegexOptions.Compiled and the source generator to use LastIndexOf in that case.

The change also entailed adding/updating a few recursive functions. The plan has been to adopt the same model as in System.Linq.Expressions, Roslyn, and elsewhere, where we fork processing to continue on a secondary thread, rather than trying to enforce some max depth or rewrite as iterative, so I've done that as part of this change as well.

As an example, the "email" benchmark from:
https://github.com/mariomka/regex-benchmark/blame/244ca6c0e4bc8dd257904c51c0b5cabba6956dd2/csharp/Benchmark.cs#L19-L20

privatereadonlystaticRegexs_email=newRegex(@"[\w\.+-]+@[\w\.-]+\.[\w\.-]+",RegexOptions.Compiled);[Benchmark]publicintEmail()=>Count(s_email,s_mariomkaInput);privatestaticintCount(Regexr,stringinput){intcount=0;Matchm=r.Match(input);while(m.Success){count++;m=m.NextMatch();}returncount;}

Method	Toolchain	Mean	Ratio
Email	\main\corerun.exe	600.2 us	1.00
Email	\pr\corerun.exe	485.2 us	0.81

And here's the generated code for the matching logic before and after...

Before

protectedoverridevoidGo(){stringruntext=base.runtext!;intruntextbeg=base.runtextbeg;intruntextend=base.runtextend;intruntextpos=base.runtextpos;int[]runtrack=base.runtrack!;intruntrackpos=base.runtrackpos;int[]runstack=base.runstack!;intrunstackpos=base.runstackpos;inttmp1,tmp2,ch;// 000000 *Lazybranch addr = 29L0:runtrack[--runtrackpos]=runtextpos;runtrack[--runtrackpos]=0;// 000002 *SetmarkL1:runstack[--runstackpos]=runtextpos;runtrack[--runtrackpos]=1;// 000003 Setrep [+-.\\w], rep = 1L2:if(runtextend-runtextpos<1){gotoBacktrack;}for(inti=0;i<1;i++){if(!((ch=runtext[runtextpos+i])<128?("\0\0栀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0004\n+,-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){gotoBacktrack;}}runtextpos++;// 000006 Setloopatomic [+-.\\w], rep = infL3:tmp1=runtextend-runtextpos;// lengthtmp2=tmp1+1;while(--tmp2>0){if(!((ch=runtext[runtextpos++])<128?("\0\0栀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0004\n+,-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){runtextpos--;break;}}// 000009 UpdateBumpalongL4:runtrack[^1]=runtextpos;// 000010 One '@'L5:if(runtextpos>=runtextend||runtext[runtextpos++]!=64){gotoBacktrack;}// 000012 Setrep [-.\\w], rep = 1L6:if(runtextend-runtextpos<1){gotoBacktrack;}for(inti=0;i<1;i++){if(!((ch=runtext[runtextpos+i])<128?("\0\0怀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0002\n-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){gotoBacktrack;}}runtextpos++;// 000015 *Setloop [-.\\w], rep = infL7:tmp1=runtextend-runtextpos;// lengthtmp2=tmp1+1;while(--tmp2>0){if(!((ch=runtext[runtextpos++])<128?("\0\0怀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0002\n-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){runtextpos--;break;}}if(tmp2>=tmp1){gotoL8;}runtrack[--runtrackpos]=tmp1-tmp2-1;runtrack[--runtrackpos]=runtextpos-1;runtrack[--runtrackpos]=2;// 000018 One '.'L8:if(runtextpos>=runtextend||runtext[runtextpos++]!=46){gotoBacktrack;}// 000020 Setrep [-.\\w], rep = 1L9:if(runtextend-runtextpos<1){gotoBacktrack;}for(inti=0;i<1;i++){if(!((ch=runtext[runtextpos+i])<128?("\0\0怀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0002\n-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){gotoBacktrack;}}runtextpos++;// 000023 Setloopatomic [-.\\w], rep = infL10:tmp1=runtextend-runtextpos;// lengthtmp2=tmp1+1;while(--tmp2>0){if(!((ch=runtext[runtextpos++])<128?("\0\0怀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0002\n-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){runtextpos--;break;}}// 000026 *Capturemark index = 0L11:tmp1=runstack[runstackpos++];base.Capture(0,tmp1,runtextpos);runtrack[--runtrackpos]=tmp1;runtrack[--runtrackpos]=3;// 000029 StopL12:base.runtextpos=runtextpos;return;Backtrack:intlimit=base.runtrackcount*4;if(runstackpos<limit){base.runstackpos=runstackpos;base.DoubleStack();// might change runstackpos and runstackrunstackpos=base.runstackpos;runstack=base.runstack!;}if(runtrackpos<limit){base.runtrackpos=runtrackpos;base.DoubleTrack();// might change runtrackpos and runtrackruntrackpos=base.runtrackpos;runtrack=base.runtrack!;}switch(runtrack[runtrackpos++]){case0:{// 000000 *Lazybranch addr = 29runtextpos=runtrack[runtrackpos++];gotoL12;}case1:{// 000002 *Setmarkrunstackpos++;gotoBacktrack;}case2:{// 000015 *Setloop [-.\\w], rep = infruntextpos=runtrack[runtrackpos++];tmp1=runtrack[runtrackpos++];// positionif(tmp1>0){runtrack[--runtrackpos]=tmp1-1;runtrack[--runtrackpos]=runtextpos-1;runtrack[--runtrackpos]=2;}gotoL8;}case3:{// 000026 *Capturemark index = 0runstack[--runstackpos]=runtrack[runtrackpos++];base.Uncapture();gotoBacktrack;}default:{global::System.Diagnostics.Debug.Fail($"Unexpected backtracking state {runtrack[runtrackpos-1]}");break;}}}

After

protectedoverridevoidGo(){stringruntext=base.runtext!;intruntextpos=base.runtextpos;intruntextend=base.runtextend;intoriginalruntextpos=runtextpos;global::System.ReadOnlySpan<byte>byteSpan;charch;global::System.ReadOnlySpan<char>textSpan=global::System.MemoryExtensions.AsSpan(runtext,runtextpos,runtextend-runtextpos);// Concatenate//{// Setloopatomic [+-.\\w]+{inti0=0;while((uint)i0<(uint)textSpan.Length&&((ch=textSpan[i0])<128?("\0\0栀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0004\n+,-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){i0++;}if(i0<1){gotoNoMatch;}textSpan=textSpan.Slice(i0);runtextpos+=i0;}// UpdateBumpalong{base.runtextpos=runtextpos;}// One '@'{if((uint)textSpan.Length<1||textSpan[0]!='@'){gotoNoMatch;}}// Setloop [-.\\w]+//{runtextpos++;textSpan=textSpan.Slice(1);intstartingRunTextPos1=runtextpos;inti4=0;while((uint)i4<(uint)textSpan.Length&&((ch=textSpan[i4])<128?("\0\0怀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0002\n-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){i4++;}if(i4<1){gotoNoMatch;}textSpan=textSpan.Slice(i4);runtextpos+=i4;intendingRunTextPos2=runtextpos;intcrawlPos3=base.Crawlpos();startingRunTextPos1+=1;gotoEndLoop1;Backtrack0:if(startingRunTextPos1>=endingRunTextPos2){gotoNoMatch;}endingRunTextPos2=runtext.LastIndexOf('.',endingRunTextPos2-1,endingRunTextPos2-startingRunTextPos1);if(endingRunTextPos2<0){gotoNoMatch;}runtextpos=endingRunTextPos2;textSpan=global::System.MemoryExtensions.AsSpan(runtext,runtextpos,runtextend-runtextpos);EndLoop1://}// One '.'{if((uint)textSpan.Length<1||textSpan[0]!='.'){gotoBacktrack0;}}// Setloopatomic [-.\\w]+{runtextpos++;textSpan=textSpan.Slice(1);inti5=0;while((uint)i5<(uint)textSpan.Length&&((ch=textSpan[i5])<128?("\0\0怀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0002\n-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){i5++;}if(i5<1){gotoBacktrack0;}textSpan=textSpan.Slice(i5);runtextpos+=i5;}//}// Matchbase.runtextpos=runtextpos;base.Capture(0,originalruntextpos,runtextpos);return;// No matchNoMatch:return;}

[ghost]

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

Issue Details

---

In .NET 5, we added simpler compiled code gen for regexes that didn't entail backtracking (or that had only very constrained backtracking, such as a top-level alternation). In our corpus of ~90K regular expressions, that code generator is employed for ~40% of them. The primary purpose of adding that code generator initially was performance, as it was able to avoid lots of the expense that original code generator had, especially for simple regexes. However, with the source generator, it's much more valuable to use this code gen as the generated code is human-readable and really helps to understand how the regex is operating, is much more easily debugged, etc.

This change allows the simplified code gen to be used even if there are backtracking single-character loops in the regex, as long as those loops are in a top-level concatenation (or a simple grouping structure like a capture). This increases the percentage of expressions in our corpus that will use the simplified code gen to ~65%.

Once we have the simplified loop code gen, it's also a lot easier to add in vectorization of searching for the next location to back off to based on a literal that comes immediately after the loop (e.g. "abc.*def"). This adds support into both RegexOptions.Compiled and the source generator to use LastIndexOf in that case.

The change also entailed adding/updating a few recursive functions. The plan has been to adopt the same model as in System.Linq.Expressions, Roslyn, and elsewhere, where we fork processing to continue on a secondary thread, rather than trying to enforce some max depth or rewrite as iterative, so I've done that as part of this change as well.

As an example, the "email" benchmark from:
https://github.com/mariomka/regex-benchmark/blame/244ca6c0e4bc8dd257904c51c0b5cabba6956dd2/csharp/Benchmark.cs#L19-L20

privatereadonlystaticRegexs_email=newRegex(@"[\w\.+-]+@[\w\.-]+\.[\w\.-]+",RegexOptions.Compiled);[Benchmark]publicintEmail()=>Count(s_email,s_mariomkaInput);privatestaticintCount(Regexr,stringinput){intcount=0;Matchm=r.Match(input);while(m.Success){count++;m=m.NextMatch();}returncount;}

Method	Toolchain	Mean	Ratio
Email	\main\corerun.exe	600.2 us	1.00
Email	\pr\corerun.exe	485.2 us	0.81

And here's the generated code for the matching logic before and after...

Before

protectedoverridevoidGo(){stringruntext=base.runtext!;intruntextbeg=base.runtextbeg;intruntextend=base.runtextend;intruntextpos=base.runtextpos;int[]runtrack=base.runtrack!;intruntrackpos=base.runtrackpos;int[]runstack=base.runstack!;intrunstackpos=base.runstackpos;inttmp1,tmp2,ch;// 000000 *Lazybranch addr = 29L0:runtrack[--runtrackpos]=runtextpos;runtrack[--runtrackpos]=0;// 000002 *SetmarkL1:runstack[--runstackpos]=runtextpos;runtrack[--runtrackpos]=1;// 000003 Setrep [+-.\\w], rep = 1L2:if(runtextend-runtextpos<1){gotoBacktrack;}for(inti=0;i<1;i++){if(!((ch=runtext[runtextpos+i])<128?("\0\0栀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0004\n+,-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){gotoBacktrack;}}runtextpos++;// 000006 Setloopatomic [+-.\\w], rep = infL3:tmp1=runtextend-runtextpos;// lengthtmp2=tmp1+1;while(--tmp2>0){if(!((ch=runtext[runtextpos++])<128?("\0\0栀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0004\n+,-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){runtextpos--;break;}}// 000009 UpdateBumpalongL4:runtrack[^1]=runtextpos;// 000010 One '@'L5:if(runtextpos>=runtextend||runtext[runtextpos++]!=64){gotoBacktrack;}// 000012 Setrep [-.\\w], rep = 1L6:if(runtextend-runtextpos<1){gotoBacktrack;}for(inti=0;i<1;i++){if(!((ch=runtext[runtextpos+i])<128?("\0\0怀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0002\n-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){gotoBacktrack;}}runtextpos++;// 000015 *Setloop [-.\\w], rep = infL7:tmp1=runtextend-runtextpos;// lengthtmp2=tmp1+1;while(--tmp2>0){if(!((ch=runtext[runtextpos++])<128?("\0\0怀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0002\n-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){runtextpos--;break;}}if(tmp2>=tmp1){gotoL8;}runtrack[--runtrackpos]=tmp1-tmp2-1;runtrack[--runtrackpos]=runtextpos-1;runtrack[--runtrackpos]=2;// 000018 One '.'L8:if(runtextpos>=runtextend||runtext[runtextpos++]!=46){gotoBacktrack;}// 000020 Setrep [-.\\w], rep = 1L9:if(runtextend-runtextpos<1){gotoBacktrack;}for(inti=0;i<1;i++){if(!((ch=runtext[runtextpos+i])<128?("\0\0怀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0002\n-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){gotoBacktrack;}}runtextpos++;// 000023 Setloopatomic [-.\\w], rep = infL10:tmp1=runtextend-runtextpos;// lengthtmp2=tmp1+1;while(--tmp2>0){if(!((ch=runtext[runtextpos++])<128?("\0\0怀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0002\n-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){runtextpos--;break;}}// 000026 *Capturemark index = 0L11:tmp1=runstack[runstackpos++];base.Capture(0,tmp1,runtextpos);runtrack[--runtrackpos]=tmp1;runtrack[--runtrackpos]=3;// 000029 StopL12:base.runtextpos=runtextpos;return;Backtrack:intlimit=base.runtrackcount*4;if(runstackpos<limit){base.runstackpos=runstackpos;base.DoubleStack();// might change runstackpos and runstackrunstackpos=base.runstackpos;runstack=base.runstack!;}if(runtrackpos<limit){base.runtrackpos=runtrackpos;base.DoubleTrack();// might change runtrackpos and runtrackruntrackpos=base.runtrackpos;runtrack=base.runtrack!;}switch(runtrack[runtrackpos++]){case0:{// 000000 *Lazybranch addr = 29runtextpos=runtrack[runtrackpos++];gotoL12;}case1:{// 000002 *Setmarkrunstackpos++;gotoBacktrack;}case2:{// 000015 *Setloop [-.\\w], rep = infruntextpos=runtrack[runtrackpos++];tmp1=runtrack[runtrackpos++];// positionif(tmp1>0){runtrack[--runtrackpos]=tmp1-1;runtrack[--runtrackpos]=runtextpos-1;runtrack[--runtrackpos]=2;}gotoL8;}case3:{// 000026 *Capturemark index = 0runstack[--runstackpos]=runtrack[runtrackpos++];base.Uncapture();gotoBacktrack;}default:{global::System.Diagnostics.Debug.Fail($"Unexpected backtracking state {runtrack[runtrackpos-1]}");break;}}}

After

protectedoverridevoidGo(){stringruntext=base.runtext!;intruntextpos=base.runtextpos;intruntextend=base.runtextend;intoriginalruntextpos=runtextpos;global::System.ReadOnlySpan<byte>byteSpan;charch;global::System.ReadOnlySpan<char>textSpan=global::System.MemoryExtensions.AsSpan(runtext,runtextpos,runtextend-runtextpos);// Concatenate//{// Setloopatomic [+-.\\w]+{inti0=0;while((uint)i0<(uint)textSpan.Length&&((ch=textSpan[i0])<128?("\0\0栀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0004\n+,-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){i0++;}if(i0<1){gotoNoMatch;}textSpan=textSpan.Slice(i0);runtextpos+=i0;}// UpdateBumpalong{base.runtextpos=runtextpos;}// One '@'{if((uint)textSpan.Length<1||textSpan[0]!='@'){gotoNoMatch;}}// Setloop [-.\\w]+//{runtextpos++;textSpan=textSpan.Slice(1);intstartingRunTextPos1=runtextpos;inti4=0;while((uint)i4<(uint)textSpan.Length&&((ch=textSpan[i4])<128?("\0\0怀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0002\n-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){i4++;}if(i4<1){gotoNoMatch;}textSpan=textSpan.Slice(i4);runtextpos+=i4;intendingRunTextPos2=runtextpos;intcrawlPos3=base.Crawlpos();startingRunTextPos1+=1;gotoEndLoop1;Backtrack0:if(startingRunTextPos1>=endingRunTextPos2){gotoNoMatch;}endingRunTextPos2=runtext.LastIndexOf('.',endingRunTextPos2-1,endingRunTextPos2-startingRunTextPos1);if(endingRunTextPos2<0){gotoNoMatch;}runtextpos=endingRunTextPos2;textSpan=global::System.MemoryExtensions.AsSpan(runtext,runtextpos,runtextend-runtextpos);EndLoop1://}// One '.'{if((uint)textSpan.Length<1||textSpan[0]!='.'){gotoBacktrack0;}}// Setloopatomic [-.\\w]+{runtextpos++;textSpan=textSpan.Slice(1);inti5=0;while((uint)i5<(uint)textSpan.Length&&((ch=textSpan[i5])<128?("\0\0怀Ͽ\ufffe蟿\ufffe\u07ff"[ch>>4]&(1<<(ch&0xF)))!=0:CharInClass((char)ch,"\0\u0002\n-/\0\u0002\u0004\u0005\u0003\u0001\u0006\t\u0013\0"))){i5++;}if(i5<1){gotoBacktrack0;}textSpan=textSpan.Slice(i5);runtextpos+=i5;}//}// Matchbase.runtextpos=runtextpos;base.Capture(0,originalruntextpos,runtextpos);return;// No matchNoMatch:return;}

Author:	stephentoub
Assignees:	-
Labels:	area-System.Text.RegularExpressions
Milestone:	7.0.0

[danmoseley]

Just curious, what does the generated code look like for this example? could you share?

[stephentoub]

Just curious, what does the generated code look like for this example? could you share?

It's already in the PR description. Expand the before/ after nodes.

[danmoseley]

It's surprisingly readable!

[stephentoub]

It's surprisingly readable!

😯 Oh ye of little faith 😄

[jeffhandley]

😯 Oh ye of little faith 😄

There's a joke here somewhere about the readability of goto statements (that is still respectful), but I don't know what it is. 😼

[stephentoub]

@BrzVlad, any idea why the Libraries Test Run release mono_interpreter Linux x64 Debug failed leg is failing here? It looks like it's getting a seg fault.

[BrzVlad]

@stephentoub Should get fixed by #60514

[stephentoub]

Thanks

[eerhardt]

Just a few questions - mostly for my learning.

[stephentoub]

@safern, some drawing tests have repeatedly failed on this PR. It's not clear to me how my changes here could have broken this, but it's failed multiple times.

 System.Drawing.Tests.PenTests.Ctor_Brush_Width<SolidBrush>(brush: SolidBrush { Color = Color [Red] }, width: 0, expectedPenType: SolidColor) [FAIL]
Assert.Equal() Failure
Expected: 0
Actual: 1
Stack Trace:
/_/src/libraries/System.Drawing.Common/tests/PenTests.cs(1384,0): at System.Drawing.Tests.PenTests.VerifyPen[T](Pen pen, PenType expectedPenType, Single expectedWidth)
/_/src/libraries/System.Drawing.Common/tests/PenTests.cs(62,0): at System.Drawing.Tests.PenTests.Ctor_Brush_Width[T](T brush, Single width, PenType expectedPenType)
System.Drawing.Tests.PenTests.Ctor_Brush_Width<SolidBrush>(brush: SolidBrush { Color = Color [Red] }, width: -1, expectedPenType: SolidColor) [FAIL]
Assert.Equal() Failure
Expected: -1
Actual: 1
Stack Trace:
/_/src/libraries/System.Drawing.Common/tests/PenTests.cs(1384,0): at System.Drawing.Tests.PenTests.VerifyPen[T](Pen pen, PenType expectedPenType, Single expectedWidth)
/_/src/libraries/System.Drawing.Common/tests/PenTests.cs(62,0): at System.Drawing.Tests.PenTests.Ctor_Brush_Width[T](T brush, Single width, PenType expectedPenType)
System.Drawing.Tests.PenTests.Ctor_Brush_Width<SolidBrush>(brush: SolidBrush { Color = Color [Red] }, width: -�, expectedPenType: SolidColor) [FAIL]
Assert.Equal() Failure
Expected: -�
Actual: 1
Stack Trace:
/_/src/libraries/System.Drawing.Common/tests/PenTests.cs(1384,0): at System.Drawing.Tests.PenTests.VerifyPen[T](Pen pen, PenType expectedPenType, Single expectedWidth)
/_/src/libraries/System.Drawing.Common/tests/PenTests.cs(62,0): at System.Drawing.Tests.PenTests.Ctor_Brush_Width[T](T brush, Single width, PenType expectedPenType)
System.Drawing.Tests.PenTests.Ctor_Color_Width(width: -1) [FAIL]
Assert.Equal() Failure
Expected: -1
Actual: 1
Stack Trace:
/_/src/libraries/System.Drawing.Common/tests/PenTests.cs(1384,0): at System.Drawing.Tests.PenTests.VerifyPen[T](Pen pen, PenType expectedPenType, Single expectedWidth)
/_/src/libraries/System.Drawing.Common/tests/PenTests.cs(116,0): at System.Drawing.Tests.PenTests.Ctor_Color_Width(Single width)
System.Drawing.Tests.PenTests.Ctor_Color_Width(width: 0) [FAIL]
Assert.Equal() Failure
Expected: 0
Actual: 1
Stack Trace:
/_/src/libraries/System.Drawing.Common/tests/PenTests.cs(1384,0): at System.Drawing.Tests.PenTests.VerifyPen[T](Pen pen, PenType expectedPenType, Single expectedWidth)
/_/src/libraries/System.Drawing.Common/tests/PenTests.cs(116,0): at System.Drawing.Tests.PenTests.Ctor_Color_Width(Single width)
System.Drawing.Tests.PenTests.Ctor_Color_Width(width: -�) [FAIL]
Assert.Equal() Failure
Expected: -�
Actual: 1
Stack Trace:
/_/src/libraries/System.Drawing.Common/tests/PenTests.cs(1384,0): at System.Drawing.Tests.PenTests.VerifyPen[T](Pen pen, PenType expectedPenType, Single expectedWidth)
/_/src/libraries/System.Drawing.Common/tests/PenTests.cs(116,0): at System.Drawing.Tests.PenTests.Ctor_Color_Width(Single width)

Is there any known issue here? I don't see any open issues for it.

[stephentoub]

Ah, I see #60731 was literally just created.

[safern]

Hmm interesting, I'll dig into what cause them to start failing and disable them. Thanks for the ping.

[kunalspathak]

Linux/x64 improvement - dotnet/perf-autofiling-issues#1975

[stephentoub]

Linux/x64 improvement

Excellent.