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Merged
siegfriedpammer merged 2 commits into from
Sep 10, 2025
+277 −0
Merged

Copy-propagate the stack slot for collection initializers #3554

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c0f50a1
Copy-propagate the stack slot for collection initializers
ds5678 Sep 8, 2025
b2ca674
Use pattern matching
ds5678 Sep 8, 2025
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2 changes: 2 additions & 0 deletions ICSharpCode.Decompiler.Tests/ICSharpCode.Decompiler.Tests.csproj
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Expand Up @@ -105,6 +105,7 @@
<None Include="TestCases\ILPretty\Issue3466.il" />
<None Include="testcases\ilpretty\Issue3504.il" />
<None Include="testcases\ilpretty\Issue3524.il" />
<None Include="testcases\ilpretty\Issue3552.il" />
<None Include="TestCases\ILPretty\MonoFixed.il" />
<None Include="TestCases\Correctness\NonGenericConstrainedCallVirt.il" />
<None Include="TestCases\ILPretty\UnknownTypes.cs" />
Expand Down Expand Up @@ -150,6 +151,7 @@
<Compile Include="TestCases\ILPretty\Issue3442.cs" />
<Compile Include="TestCases\ILPretty\Issue3466.cs" />
<Compile Include="TestCases\ILPretty\Issue3524.cs" />
<Compile Include="TestCases\ILPretty\Issue3552.cs" />
<Compile Include="TestCases\Pretty\ExpandParamsArgumentsDisabled.cs" />
<Compile Include="TestCases\Pretty\ExtensionProperties.cs" />
<None Include="TestCases\ILPretty\Issue3504.cs" />
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6 changes: 6 additions & 0 deletions ICSharpCode.Decompiler.Tests/ILPrettyTestRunner.cs
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Expand Up @@ -249,6 +249,12 @@ public async Task Issue3524()
await Run();
}

[Test]
public async Task Issue3552()
{
await Run();
}

[Test]
public async Task Issue2260SwitchString()
{
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66 changes: 66 additions & 0 deletions ICSharpCode.Decompiler.Tests/TestCases/ILPretty/Issue3552.cs
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@@ -0,0 +1,66 @@
using System;
using System.Collections;
using System.Collections.Generic;

namespace ICSharpCode.Decompiler.Tests.TestCases.ILPretty
{
public static class Issue3552
{
public static Issue3552_IntegerPair MakePair1(int x, int y)
{
Issue3552_IntegerPairBuilder issue3552_IntegerPairBuilder = new Issue3552_IntegerPairBuilder { x, y };
return issue3552_IntegerPairBuilder.ToPair();
}
public static Issue3552_IntegerPair MakePair2(int x, int y)
{
Issue3552_IntegerPairBuilder issue3552_IntegerPairBuilder = new Issue3552_IntegerPairBuilder { x, y };
return issue3552_IntegerPairBuilder.ToPair();
}
public static Issue3552_IntegerPair MakePair3(int x, int y)
{
Issue3552_IntegerPairBuilder issue3552_IntegerPairBuilder = new Issue3552_IntegerPairBuilder { x, y };
return issue3552_IntegerPairBuilder.ToPair();
}
}
public struct Issue3552_IntegerPair
{
public int X;
public int Y;
}
public struct Issue3552_IntegerPairBuilder : IEnumerable<int>, IEnumerable
{
private int index;
private Issue3552_IntegerPair pair;

public readonly Issue3552_IntegerPair ToPair()
{
return pair;
}

public void Add(int value)
{
switch (index)
{
case 0:
pair.X = value;
break;
case 1:
pair.Y = value;
break;
default:
throw new IndexOutOfRangeException();
}
index++;
}

public IEnumerator<int> GetEnumerator()
{
return null;
}

IEnumerator IEnumerable.GetEnumerator()
{
return GetEnumerator();
}
}
}
198 changes: 198 additions & 0 deletions ICSharpCode.Decompiler.Tests/TestCases/ILPretty/Issue3552.il
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@@ -0,0 +1,198 @@
.class public auto ansi abstract sealed beforefieldinit ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552
extends [System.Runtime]System.Object
{
// Methods
.method public hidebysig static
valuetype ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPair MakePair1 (
int32 x,
int32 y
) cil managed
{
// Method begins at RVA 0x2050
// Header size: 12
// Code size: 34 (0x22)
.maxstack 2
.locals init (
[0] valuetype ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder
)

IL_0000: ldloca.s 0
IL_0002: initobj ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder
IL_0008: ldloca.s 0
IL_000a: ldarg.0
IL_000b: call instance void ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder::Add(int32)
IL_0010: ldloca.s 0
IL_0012: ldarg.1
IL_0013: call instance void ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder::Add(int32)
IL_0015: ldloca.s 0
IL_001c: call instance valuetype ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPair ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder::ToPair()
IL_0021: ret
} // end of method Issue3552::MakePair1

.method public hidebysig static
valuetype ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPair MakePair2 (
int32 x,
int32 y
) cil managed
{
// Method begins at RVA 0x2050
// Header size: 12
// Code size: 34 (0x22)
.maxstack 2
.locals init (
[0] valuetype ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder
)

IL_0000: ldloca.s 0
IL_0001: dup
IL_0002: initobj ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder
IL_0008: dup
IL_000a: ldarg.0
IL_000b: call instance void ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder::Add(int32)
IL_0012: ldarg.1
IL_0013: call instance void ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder::Add(int32)
IL_0015: ldloca.s 0
IL_001c: call instance valuetype ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPair ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder::ToPair()
IL_0021: ret
} // end of method Issue3552::MakePair2

.method public hidebysig static
valuetype ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPair MakePair3 (
int32 x,
int32 y
) cil managed
{
// Method begins at RVA 0x2050
// Header size: 12
// Code size: 34 (0x22)
.maxstack 2
.locals init (
[0] valuetype ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder
)

IL_0000: ldloca.s 0
IL_0001: dup
IL_0002: initobj ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder
IL_0008: dup
IL_000a: ldarg.0
IL_000b: call instance void ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder::Add(int32)
IL_0010: dup
IL_0012: ldarg.1
IL_0013: call instance void ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder::Add(int32)
IL_001c: call instance valuetype ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPair ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder::ToPair()
IL_0021: ret
} // end of method Issue3552::MakePair3

} // end of class ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552

.class public sequential ansi sealed beforefieldinit ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPair
extends [System.Runtime]System.ValueType
{
// Fields
.field public int32 X
.field public int32 Y

} // end of class ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPair

.class public sequential ansi sealed beforefieldinit ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder
extends [System.Runtime]System.ValueType
implements class [System.Runtime]System.Collections.Generic.IEnumerable`1<int32>,
[System.Runtime]System.Collections.IEnumerable
{
// Fields
.field private int32 index
.field private valuetype ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPair pair

// Methods
.method public hidebysig
instance valuetype ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPair ToPair () cil managed
{
.custom instance void [System.Runtime]System.Runtime.CompilerServices.IsReadOnlyAttribute::.ctor() = (
01 00 00 00
)
// Method begins at RVA 0x207e
// Header size: 1
// Code size: 7 (0x7)
.maxstack 8

IL_0000: ldarg.0
IL_0001: ldfld valuetype ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPair ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder::pair
IL_0006: ret
} // end of method Issue3552_IntegerPairBuilder::ToPair

.method public hidebysig
instance void Add (
int32 'value'
) cil managed
{
// Method begins at RVA 0x2088
// Header size: 12
// Code size: 65 (0x41)
.maxstack 3
.locals init (
[0] int32
)

IL_0000: ldarg.0
IL_0001: ldfld int32 ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder::index
IL_0006: stloc.0
IL_0007: ldloc.0
IL_0008: brfalse.s IL_0010

IL_000a: ldloc.0
IL_000b: ldc.i4.1
IL_000c: beq.s IL_001e

IL_000e: br.s IL_002c

IL_0010: ldarg.0
IL_0011: ldflda valuetype ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPair ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder::pair
IL_0016: ldarg.1
IL_0017: stfld int32 ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPair::X
IL_001c: br.s IL_0032

IL_001e: ldarg.0
IL_001f: ldflda valuetype ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPair ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder::pair
IL_0024: ldarg.1
IL_0025: stfld int32 ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPair::Y
IL_002a: br.s IL_0032

IL_002c: newobj instance void [System.Runtime]System.IndexOutOfRangeException::.ctor()
IL_0031: throw

IL_0032: ldarg.0
IL_0033: ldarg.0
IL_0034: ldfld int32 ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder::index
IL_0039: ldc.i4.1
IL_003a: add
IL_003b: stfld int32 ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder::index
IL_0040: ret
} // end of method Issue3552_IntegerPairBuilder::Add

.method public final hidebysig newslot virtual
instance class [System.Runtime]System.Collections.Generic.IEnumerator`1<int32> GetEnumerator () cil managed
{
// Method begins at RVA 0x20d5
// Header size: 1
// Code size: 2 (0x2)
.maxstack 8

IL_0000: ldnull
IL_0001: ret
} // end of method Issue3552_IntegerPairBuilder::GetEnumerator

.method private final hidebysig newslot virtual
instance class [System.Runtime]System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator () cil managed
{
.override method instance class [System.Runtime]System.Collections.IEnumerator [System.Runtime]System.Collections.IEnumerable::GetEnumerator()
// Method begins at RVA 0x20d8
// Header size: 1
// Code size: 7 (0x7)
.maxstack 8

IL_0000: ldarg.0
IL_0001: call instance class [System.Runtime]System.Collections.Generic.IEnumerator`1<int32> ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder::GetEnumerator()
IL_0006: ret
} // end of method Issue3552_IntegerPairBuilder::System.Collections.IEnumerable.GetEnumerator

} // end of class ICSharpCode.Decompiler.Tests.TestCases.ILPretty.Issue3552_IntegerPairBuilder
5 changes: 5 additions & 0 deletions ICSharpCode.Decompiler/IL/Transforms/TransformCollectionAndObjectInitializers.cs
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Expand Up @@ -97,6 +97,11 @@ void IStatementTransform.Run(Block block, int pos, StatementTransformContext con
}
return;
}
// Copy-propagate stack slot holding an 'ldloca' of the variable
if (pos < block.Instructions.Count && block.Instructions[pos + 1] is StLoc { Variable: { Kind: VariableKind.StackSlot, IsSingleDefinition: true }, Value: LdLoca ldLoca } stLocStack && ldLoca.Variable == v)
{
CopyPropagation.Propagate(stLocStack, context);
}
int initializerItemsCount = 0;
bool initializerContainsInitOnlyItems = false;
possibleIndexVariables.Clear();
Expand Down
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