JIT: save pgo data in inline context, use it for call optimization#116241
JIT: save pgo data in inline context, use it for call optimization#116241AndyAyersMS merged 3 commits intodotnet:mainfrom
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Fix dotnet#116223 Save profile data (schema, schema size, and data) in the inline context. Always store the inline context in GT_CALL nodes. Use this to find the correct PGO data to consult when optimizing a call (in particular, for late cast expansions).
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Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch |
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Pull Request Overview
This PR enhances PGO-driven inlining by storing per-method profile data in the inline context and leveraging it during call optimization (especially for late cast expansions), and also refines dump logging.
- Introduce
PgoInfoand store PGO data insideInlineContext - Propagate PGO info into calls and update
pickGDVto consume it with a newverboseLoggingflag - Enable dumping of PGO-driven type guesses in
gtDispTreefor cast helpers
Reviewed Changes
Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.
Show a summary per file
| File | Description |
|---|---|
| src/coreclr/jit/inline.h | Define PgoInfo and add Get/Set/HasPgoInfo to InlineContext |
| src/coreclr/jit/inline.cpp | Implement PgoInfo constructors |
| src/coreclr/jit/importercalls.cpp | Use InlineContext PGO data in pickGDV and add verboseLogging |
| src/coreclr/jit/helperexpansion.cpp | Switch cast-expansion arrays from MAX_CAST_GUESSES to MAX_GDV_TYPE_CHECKS |
| src/coreclr/jit/gentree.h | Make gtInlineContext unconditionally available |
| src/coreclr/jit/gentree.cpp | Assign gtInlineContext on new/clone calls and dump PGO data for cast helpers |
| src/coreclr/jit/compiler.h | Add verboseLogging parameter (default true) to pickGDV signature |
| src/coreclr/jit/compiler.cpp | Call SetPgoInfo on compInlineContext during initialization |
Comments suppressed due to low confidence (2)
src/coreclr/jit/helperexpansion.cpp:2160
- The call to
pickGDVis missing the newverboseLoggingargument, leading to a signature mismatch. Add abool verboseLoggingparameter (e.g.,trueorfalse) to match the updated signature.
comp->pickGDV(castHelper, castHelper->gtCastHelperILOffset, false, likelyClasses, nullptr, &likelyClassCount, likelyLikelihoods);
src/coreclr/jit/compiler.cpp:2557
- Add tests to verify that
SetPgoInfocorrectly stores PGO schema, count, and data, and thatHasPgoInfo/GetPgoInforeturn the expected values in inlined contexts.
compInlineContext->SetPgoInfo(PgoInfo(this));
| } | ||
| #endif | ||
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| const PgoInfo& GetPgoInfo() |
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[nitpick] Consider adding a brief doc comment explaining what GetPgoInfo, SetPgoInfo, and HasPgoInfo do, and how PgoInfo is intended to be used within inlining.
| int* candidatesCount, | ||
| unsigned* likelihoods); | ||
| unsigned* likelihoods, | ||
| bool verboseLogging = true); |
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[nitpick] The pickGDV parameter list is growing; consider grouping related flags (like verboseLogging) and PGO inputs into a struct to simplify calls and reduce maintenance risk.
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@dotnet/jit-contrib FYI Makes GT_CALL nodes bigger. Should fix a number of inlining-related perf issues, like #113913. Reasonble number of diffs. For one benchmark there I have locally
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@EgorBot -amd -arm using System.Runtime.CompilerServices;
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;
BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);
public class Benchmarks
{
int class1 = 0;
int class2 = 0;
BaseClass b1 = new DerivedClass1();
BaseClass b2 = new DerivedClass2();
[Benchmark]
public void Bench()
{
for (int i = 0; i < 10000; i++)
Problem(i);
}
[MethodImpl(MethodImplOptions.NoInlining)]
public void Problem(int i)
{
BaseClass b = i % 3 == 0 ? b1 : b2;
if (b is DerivedClass1)
class1++;
else if (IsDerivedClass2(b))
class2++;
}
public bool IsDerivedClass2(BaseClass b) => b is DerivedClass2;
public class BaseClass { }
public class DerivedClass1 : BaseClass { }
public class DerivedClass2 : BaseClass { }
} |
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hm.. @AndyAyersMS any idea why your initial repro snippet regresses with your PR? EgorBot/runtime-utils#376 It looks like the casts no longer expand with PGO at all there |
Odd. It was working ok for me locally. Let me double-check. |
It works with checked builds -- there is a misplaced #endif preventing profile capture. |
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@EgorBot -amd -arm using System.Runtime.CompilerServices;
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;
BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);
public class Benchmarks
{
int class1 = 0;
int class2 = 0;
BaseClass b1 = new DerivedClass1();
BaseClass b2 = new DerivedClass2();
[Benchmark]
public void Bench()
{
for (int i = 0; i < 10000; i++)
Problem(i);
}
[MethodImpl(MethodImplOptions.NoInlining)]
public void Problem(int i)
{
BaseClass b = i % 3 == 0 ? b1 : b2;
if (b is DerivedClass1)
class1++;
else if (IsDerivedClass2(b))
class2++;
}
public bool IsDerivedClass2(BaseClass b) => b is DerivedClass2;
public class BaseClass { }
public class DerivedClass1 : BaseClass { }
public class DerivedClass2 : BaseClass { }
} |
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Results look better now BenchmarkDotNet v0.14.0, Ubuntu 24.04.2 LTS (Noble Numbat)
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/ba-g unrelated failure with no helix log |
Fix #116223
Save profile data (schema, schema size, and data) in the inline context.
Always store the inline context in GT_CALL nodes. Use this to find
the correct PGO data to consult when optimizing a call (in particular,
for late cast expansions).
Also pick up the dumping improvements from #116231.