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JIT: boost inlining for methods that may return small arrays #114806

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Merged
merged 3 commits into from
Apr 24, 2025
Merged

JIT: boost inlining for methods that may return small arrays #114806

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5d4a574
JIT: boost inlining for methods that may return small arrays
AndyAyersMS Apr 17, 2025
fa67ccb
Merge branch 'main' into InlineeAllocatesSmallFixedSizedArrayAndRetur…
AndyAyersMS Apr 24, 2025
ee7fe32
fix
AndyAyersMS Apr 24, 2025
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44 changes: 38 additions & 6 deletions src/coreclr/jit/fgbasic.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -915,12 +915,14 @@ void Compiler::fgFindJumpTargets(const BYTE* codeAddr, IL_OFFSET codeSize, Fixed
var_types varType = DUMMY_INIT(TYP_UNDEF); // TYP_ type
bool typeIsNormed = false;
FgStack pushedStack;
const bool isForceInline = (info.compFlags & CORINFO_FLG_FORCEINLINE) != 0;
const bool isInlining = compIsForInlining();
unsigned retBlocks = 0;
int prefixFlags = 0;
bool preciseScan = makeInlineObservations && compInlineResult->GetPolicy()->RequiresPreciseScan();
const bool resolveTokens = preciseScan;
const bool isForceInline = (info.compFlags & CORINFO_FLG_FORCEINLINE) != 0;
const bool isInlining = compIsForInlining();
unsigned retBlocks = 0;
int prefixFlags = 0;
bool preciseScan = makeInlineObservations && compInlineResult->GetPolicy()->RequiresPreciseScan();
const bool resolveTokens = preciseScan;
bool isReturnsArrayKnown = false;
bool returnsArray = false;

// Track offsets where IL instructions begin in DEBUG builds. Used to
// validate debug info generated by the JIT.
Expand Down Expand Up @@ -2441,6 +2443,36 @@ void Compiler::fgFindJumpTargets(const BYTE* codeAddr, IL_OFFSET codeSize, Fixed
retBlocks++;
break;

case CEE_NEWARR:

if (makeInlineObservations)
{
if (!isReturnsArrayKnown)
{
if (info.compRetType == TYP_REF)
{
CORINFO_CLASS_HANDLE retClass = info.compMethodInfo->args.retTypeClass;
if (retClass != NO_CLASS_HANDLE)
{
uint32_t retClassAttribs = info.compCompHnd->getClassAttribs(retClass);
returnsArray = (retClassAttribs & CORINFO_FLG_ARRAY) != 0;
}
}
isReturnsArrayKnown = true;
}

if (returnsArray && pushedStack.IsStackAtLeastOneDeep())
{
FgStack::FgSlot slot0 = pushedStack.GetSlot0();

if (FgStack::IsConstantOrConstArg(slot0, impInlineInfo))
{
compInlineResult->Note(InlineObservation::CALLEE_MAY_RETURN_SMALL_ARRAY);
}
}
}
break;

default:
break;
}
Expand Down
1 change: 1 addition & 0 deletions src/coreclr/jit/inline.def
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Expand Up @@ -101,6 +101,7 @@ INLINE_OBSERVATION(IS_SIZE_DECREASING_INLINE, bool, "size decreasing inline",
INLINE_OBSERVATION(LOG_REPLAY_ACCEPT, bool, "accepted by log replay", INFORMATION, CALLEE)
INLINE_OBSERVATION(LOOKS_LIKE_WRAPPER, bool, "thin wrapper around a call", INFORMATION, CALLEE)
INLINE_OBSERVATION(MAXSTACK, int, "maxstack", INFORMATION, CALLEE)
INLINE_OBSERVATION(MAY_RETURN_SMALL_ARRAY, bool, "may return a small new array", INFORMATION, CALLEE)
INLINE_OBSERVATION(OPCODE, int, "next opcode in IL stream", INFORMATION, CALLEE)
INLINE_OBSERVATION(OPCODE_NORMED, int, "next opcode in IL stream", INFORMATION, CALLEE)
INLINE_OBSERVATION(NUMBER_OF_ARGUMENTS, int, "number of arguments", INFORMATION, CALLEE)
Expand Down
11 changes: 11 additions & 0 deletions src/coreclr/jit/inlinepolicy.cpp
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Expand Up @@ -1341,6 +1341,10 @@ void ExtendedDefaultPolicy::NoteBool(InlineObservation obs, bool value)
m_ArgUnboxExact++;
break;

case InlineObservation::CALLEE_MAY_RETURN_SMALL_ARRAY:
m_MayReturnSmallArray = true;
break;

default:
DefaultPolicy::NoteBool(obs, value);
break;
Expand Down Expand Up @@ -1776,6 +1780,12 @@ double ExtendedDefaultPolicy::DetermineMultiplier()
}
}

if (m_MayReturnSmallArray)
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Copilot AI Apr 24, 2025

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It might help maintainability to add a comment explaining why the multiplier is increased by 4.0 when a small array return is observed.

Copilot uses AI. Check for mistakes.

{
multiplier += 4.0;
JITDUMP("\nInline candidate may return small known-size array. Multiplier increased to %g.", multiplier);
}

if (m_HasProfileWeights)
{
// There are cases when Profile Data can be misleading or polluted:
Expand Down Expand Up @@ -1889,6 +1899,7 @@ void ExtendedDefaultPolicy::OnDumpXml(FILE* file, unsigned indent) const
XATTR_B(m_IsCallsiteInNoReturnRegion)
XATTR_B(m_HasProfileWeights)
XATTR_B(m_InsideThrowBlock)
XATTR_B(m_MayReturnSmallArray)
}
#endif

Expand Down
2 changes: 2 additions & 0 deletions src/coreclr/jit/inlinepolicy.h
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Expand Up @@ -226,6 +226,7 @@ class ExtendedDefaultPolicy : public DefaultPolicy
, m_NonGenericCallsGeneric(false)
, m_IsCallsiteInNoReturnRegion(false)
, m_HasProfileWeights(false)
, m_MayReturnSmallArray(false)
{
// Empty
}
Expand Down Expand Up @@ -281,6 +282,7 @@ class ExtendedDefaultPolicy : public DefaultPolicy
bool m_NonGenericCallsGeneric : 1;
bool m_IsCallsiteInNoReturnRegion : 1;
bool m_HasProfileWeights : 1;
bool m_MayReturnSmallArray : 1;
};

// DiscretionaryPolicy is a variant of the default policy. It
Expand Down
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