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Merged
jakobbotsch merged 7 commits into from
Sep 10, 2021
Merged

Add cast when replacing promoted struct with field in lowering #58589

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960be87
Add cast when replacing promoted struct with field in lowering
jakobbotsch Sep 2, 2021
aabdb12
Add test
jakobbotsch Sep 2, 2021
7a55f1e
Fix formatting
jakobbotsch Sep 2, 2021
48c8474
Fix test cases
jakobbotsch Sep 3, 2021
5ce3a0f
Type returned-struct-as-primitive correctly for normalization
jakobbotsch Sep 9, 2021
72d0c9d
Fix assertion
jakobbotsch Sep 9, 2021
5250719
Run jit-format
jakobbotsch Sep 9, 2021
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Add test
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@jakobbotsch
jakobbotsch committed Sep 2, 2021
commit aabdb1200507602f691736dda12c46de65170dc2
29 changes: 29 additions & 0 deletions src/tests/JIT/Regression/JitBlue/Runtime_58373/Runtime_58373.cs
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// Licensed to the .NET Foundation under one or more agreements.
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@sandreenko sandreenko Sep 3, 2021

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could you please tell me which complus are needed to repro it on x64 windows?

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@jakobbotsch jakobbotsch Sep 3, 2021

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I must have made a blunder somewhere, this test does not repro it for me either. It seems on x64 we normalize when we move the arg to the outgoing arg area/into arg register. So we need a little bit more. This exposes it on x64:

using System;
using System.Runtime.CompilerServices;

public unsafe class Runtime_58373
{
    public static int Main()
    {
        short halfValue = HalfToInt16Bits(MakeHalf());
        int x = halfValue;
        short val2 = HalfToInt16Bits(*(Half*)&x);

        return halfValue == val2 ? 100 : -1;
    }

    [MethodImpl(MethodImplOptions.NoInlining)]
    static Half MakeHalf()
    {
        return (Half)(-1.0f);
    }

    [MethodImpl(MethodImplOptions.NoInlining)]
    static short HalfToInt16Bits(Half h)
    {
        return *(short*)&h;
    }
}

This one exposes it on x86 without unsafe except for the reinterp:

using System;
using System.Runtime.CompilerServices;

public unsafe class Runtime_58373
{
    public static int Main()
    {
        // Use up a lot of registers
        int a = GetVal();
        int b = GetVal();
        int c = GetVal();
        int d = GetVal();
        int e = GetVal();
        int f = GetVal();
        int g = GetVal();
        int h = GetVal();
        int i = GetVal();

        short val1 = HalfToInt16Bits(MakeHalf());
        Half half = MakeHalf();
        MakeHalf(); // This will spill lower 16 bits of 'half' to memory
        short val2 = HalfToInt16Bits(half); // This will pass 32 bits as arg with upper 16 bits undefined

        return val1 == val2 ? 100 + a + b + c + d + e + f + g + h + i : -1;
    }

    [MethodImpl(MethodImplOptions.NoInlining)]
    static int GetVal()
    {
        return 0;
    }

    [MethodImpl(MethodImplOptions.NoInlining)]
    static Half MakeHalf()
    {
        return default;
    }

    [MethodImpl(MethodImplOptions.NoInlining)]
    static short HalfToInt16Bits(Half h)
    {
        return *(short*)&h;
    }
}

I will change the test to use these cases.

// The .NET Foundation licenses this file to you under the MIT license.

using System;
using System.Runtime.CompilerServices;

public unsafe class Runtime_58373
{
public static int Main()
{
FillStack(0, 0, 0, 0, 0, 0, 0xdeadbeef);
short val1 = HalfToInt16Bits(0, 0, 0, 0, 0, 0, (Half)42f);
FillStack(0, 0, 0, 0, 0, 0, 0xf000baaa);
short val2 = HalfToInt16Bits(0, 0, 0, 0, 0, 0, (Half)42f);

return val1 == val2 ? 100 : -1;
}

[MethodImpl(MethodImplOptions.NoInlining)]
static void FillStack(int a0, int a1, int a2, int a3, int a4, int a5, uint onStack)
{
}

[MethodImpl(MethodImplOptions.NoInlining)]
static short HalfToInt16Bits(int a0, int a1, int a2, int a3, int a4, int a5, Half h)
{
return *(short*)&h;
}
}
13 changes: 13 additions & 0 deletions src/tests/JIT/Regression/JitBlue/Runtime_58373/Runtime_58373.csproj
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<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<OutputType>Exe</OutputType>
</PropertyGroup>
<PropertyGroup>
<DebugType>None</DebugType>
<Optimize>True</Optimize>
<AllowUnsafeBlocks>True</AllowUnsafeBlocks>
</PropertyGroup>
<ItemGroup>
<Compile Include="$(MSBuildProjectName).cs" />
</ItemGroup>
</Project>