JIT should be able to elide zeroing of fields after allocations

[jakobbotsch]

using System;

class Program
{
    static void Main()
    {
        Program p = new();
        p.Test = false;
    }

    public bool Test;
}

Codegen:

       call     CORINFO_HELP_NEWSFAST
       mov      byte  ptr [rax+0x08], 0

Expected:

       call     CORINFO_HELP_NEWSFAST

I looked at representing this in VN once, but it seemed hard with how we represent memory in VN.

[ghost]

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Issue Details

---

using System;

class Program
{
    static void Main()
    {
        Program p = new();
        p.Test = false;
    }

    public bool Test;
}

Codegen:

       call     CORINFO_HELP_NEWSFAST
       mov      byte  ptr [rax+0x08], 0

Expected:

       call     CORINFO_HELP_NEWSFAST

I looked at representing this in VN once, but it seemed hard with how we represent memory in VN.

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

[EgorBo]

... and remove the allocation after it 🙂