Allocate boxed static structs on Frozen Object Heap

[EgorBo]

Contributes to #76151

All static fields of value types (non-primitive) are usually boxed and stored in the normal heap. This PR moves them to the Frozen Object Heap, it allows us to avoid an indirect load when we access them (we no longer need a pinned handle to the "movable" object).

Example:

staticDateTimeDate{get;set;}

Codegen for the getter:

; Assembly listing for method Proga:get_Date():System.DateTime
; Tier-1 compilation
- 48B8C01E00BDFC010000 mov rax, 0x1FCBD001EC0 ; box for Proga:<Date>k__BackingField- 488B00 mov rax, gword ptr [rax]- 488B4008 mov rax, qword ptr [rax+08H]+ 48B8C01EC0BC2B010000 mov rax, 0x12BBCC01EC0 ; data for Proga:<Date>k__BackingField+ 488B00 mov rax, qword ptr [rax]
C3 ret -; Total bytes of code 18+; Total bytes of code 14

Diffs for Libraries (jit-utils -f -pmi):

Summary of Code Size diffs:
(Lower is better)
Total bytes of base: 59050516
Total bytes of diff: 59014832
Total bytes of delta: -35684 (-0.06 % of base)
Total relative delta: -214.62
diff is an improvement.
relative diff is an improvement.
Total byte diff includes 0 bytes from reconciling methods
Base had 1 unique methods, 103 unique bytes
Diff had 1 unique methods, 103 unique bytes
Top file regressions (bytes):
339 : System.Data.Common.dasm (0.02% of base)
106 : System.Management.dasm (0.03% of base)
92 : System.Diagnostics.EventLog.dasm (0.07% of base)
21 : System.Threading.RateLimiting.dasm (0.01% of base)
4 : Newtonsoft.Json.dasm (0.00% of base)
Top file improvements (bytes):
-30685 : Microsoft.Diagnostics.Tracing.TraceEvent.dasm (-0.84% of base)
-2287 : FSharp.Core.dasm (-0.06% of base)
-863 : System.Private.Xml.dasm (-0.02% of base)
-503 : System.Reflection.DispatchProxy.dasm (-2.10% of base)
-396 : System.Data.OleDb.dasm (-0.12% of base)
-303 : Microsoft.CodeAnalysis.dasm (-0.02% of base)
-282 : System.Formats.Asn1.dasm (-0.29% of base)
-172 : Microsoft.Extensions.DependencyInjection.dasm (-0.27% of base)
-115 : System.Private.CoreLib.dasm (-0.01% of base)
-100 : Microsoft.CodeAnalysis.VisualBasic.dasm (-0.00% of base)
-56 : System.ComponentModel.TypeConverter.dasm (-0.02% of base)
-44 : System.Runtime.Caching.dasm (-0.07% of base)
-41 : System.Runtime.Numerics.dasm (-0.03% of base)
-38 : System.Transactions.Local.dasm (-0.02% of base)
-36 : OSExtensions.dasm (-0.35% of base)
-32 : System.Drawing.Common.dasm (-0.01% of base)
-28 : System.Private.DataContractSerialization.dasm (-0.00% of base)
-28 : Microsoft.Diagnostics.FastSerialization.dasm (-0.01% of base)
-26 : System.DirectoryServices.AccountManagement.dasm (-0.01% of base)
-24 : System.Net.Http.dasm (-0.00% of base)
-24 : System.Text.RegularExpressions.dasm (-0.00% of base)
-22 : Microsoft.Extensions.FileProviders.Physical.dasm (-0.13% of base)
-20 : System.Diagnostics.PerformanceCounter.dasm (-0.02% of base)
-20 : System.Linq.Expressions.dasm (-0.00% of base)
-17 : System.Net.Http.WinHttpHandler.dasm (-0.01% of base)
-15 : System.Net.HttpListener.dasm (-0.01% of base)
-14 : System.Reflection.Metadata.dasm (-0.00% of base)
-12 : System.Console.dasm (-0.02% of base)
-8 : Microsoft.CodeAnalysis.CSharp.dasm (-0.00% of base)
-8 : System.Text.Json.dasm (-0.00% of base)
41 total files with Code Size differences (36 improved, 5 regressed), 233 unchanged
4966 total methods with Code Size differences (4920 improved, 46 regressed), 356408 unchanged

TODO: Avoid allocating the pinned handle for the boxed structs.

[ghost]

Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch
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Issue Details

---

Contributes to #76151

All static fields of value types (non-primitive) are usually boxed and stored in the normal heap. This PR moves them to the Frozen Object Heap, it allows us to avoid an indirect load when we access them (we no longer need a pinned handle to the "movable" object).

Example:

staticDateTimeDate{get;set;}

Codegen for the getter:

; Assembly listing for method Proga:get_Date():System.DateTime
; Tier-1 compilation
- 48B8C01E00BDFC010000 mov rax, 0x1FCBD001EC0 ; box for Proga:<Date>k__BackingField+ 48B8E81C94C107020000 mov rax, 0x207C1941CE8 ; 'System.DateTime'- 488B00 mov rax, gword ptr [rax]
488B4008 mov rax, qword ptr [rax+08H]
C3 ret -; Total bytes of code 18+; Total bytes of code 15

Diffs for Libraries (jit-utils -f -pmi):

Total bytes of delta: -24086 (-0.04 % of base)
Total relative delta: -162.40
diff is an improvement.
relative diff is an improvement.
Total byte diff includes -206 bytes from reconciling methods
Base had 2 unique methods, 206 unique bytes
Diff had 0 unique methods, 0 unique bytes
Top file regressions (bytes):
49 : System.Threading.RateLimiting.dasm (0.03% of base)
20 : Newtonsoft.Json.dasm (0.00% of base)
Top file improvements (bytes):
-21844 : Microsoft.Diagnostics.Tracing.TraceEvent.dasm (-0.60% of base)
-510 : System.Private.Xml.dasm (-0.01% of base)
-393 : System.Reflection.DispatchProxy.dasm (-1.64% of base)
-244 : System.Data.Common.dasm (-0.01% of base)
-233 : Microsoft.CodeAnalysis.dasm (-0.01% of base)
-198 : System.Data.OleDb.dasm (-0.06% of base)
-141 : System.Formats.Asn1.dasm (-0.15% of base)
-117 : Microsoft.Extensions.DependencyInjection.dasm (-0.19% of base)
-83 : System.Private.CoreLib.dasm (-0.00% of base)
-42 : System.ComponentModel.TypeConverter.dasm (-0.01% of base)
-32 : System.Console.dasm (-0.06% of base)
-27 : Microsoft.CodeAnalysis.VisualBasic.dasm (-0.00% of base)
-27 : OSExtensions.dasm (-0.26% of base)
-21 : Microsoft.Diagnostics.FastSerialization.dasm (-0.01% of base)
-18 : System.Runtime.Numerics.dasm (-0.01% of base)
-18 : System.Speech.dasm (-0.00% of base)
-18 : System.DirectoryServices.AccountManagement.dasm (-0.00% of base)
-18 : System.Diagnostics.PerformanceCounter.dasm (-0.02% of base)
-15 : Microsoft.Extensions.FileProviders.Physical.dasm (-0.09% of base)
-15 : System.Text.RegularExpressions.dasm (-0.00% of base)
4887 total methods with Code Size differences (4870 improved, 17 regressed), 387406 unchanged

TODO: Avoid allocating the pinned handle for the boxed structs.

Author:	EgorBo
Assignees:	-
Labels:	area-CodeGen-coreclr
Milestone:	-

[EgorBo]

@jkotas do we want to avoid allocations of handles here and use that & 1 logic?

Looks like even large apps don't use statics that a lot to care about? the bingsnr ends up emitting 16kb of statics on FOH with this PR only. So it's only about a slightly better codegen.

[jkotas]

What is the handle you have in mind? I do not think there is any handle to save, without completely redoing how statics are allocated.

[EgorBo]

What is the handle you have in mind? I do not think there is any handle to save, without completely redoing how statics are allocated.

Alright, so then it's ok as is?

[MichalStrehovsky]

@MichalStrehovsky do you plan to resurrect your PR to improve statics in NativeAOT (as far as I understand even statics of primitive types currently require the helper call)? if not I can take a look 🙂 as we've got rid of getFieldAddress api completely

I was only looking at it because nobody else was and it bothers me :). You'll likely be able to come up with a much better fix and much faster than me. Thank you!

[EgorBo]

Had to fix an outerloop test that expected statics to change address after GC.Collect()

[EgorBo]

/azp run runtime-coreclr pgo, runtime-coreclr libraries-pgo

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).

[EgorBo]

note: I'm investigating a flaky NullReferenceException happening in System.Text.RegularExpression tests

 System.Text.RegularExpressions.Tests.AttRegexTests.Test(engine: SourceGenerated, options: None, pattern: "abc", input: "abc", expected: "(0,3)", skipNonBacktracking: False) [FAIL]
System.TypeInitializationException : The type initializer for 'System.Text.RegularExpressions.Generated.<RegexGenerator_g>F1__Get0_0' threw an exception.
---- System.TypeInitializationException : The type initializer for 'System.Text.RegularExpressions.Generated.<RegexGenerator_g>F1__Utilities' threw an exception.
-------- System.NullReferenceException : Object reference not set to an instance of an object.
Stack Trace:
System.Text.RegularExpressions.Generator\System.Text.RegularExpressions.Generator.RegexGenerator\RegexGenerator.g.cs(16,0): at C.Get0()
at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor)

[EgorBo]

Oops, bad rebase. I think I've found the reason, it was an incorrect fix to handle EqualityComparer.Default field (to remove it under GTF_CALL_M_HELPER_SPECIAL_DCE flag), fixed via 3db4522 it used to be able to drop any IR tree with IND(anything).
the rest of changes are untouched

[EgorBo]

llvmfullaot pipeline fails because of #78290