From: Michal Strehovský <MichalStrehovsky@users.noreply.github.com>
Date: Sat, 22 Jul 2023 12:54:19 +0000 (+0900)
Subject: Set BaseSize of interfaces to 0 (#89343)
X-Git-Tag: accepted/tizen/unified/riscv/20231226.055536~835
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a2ce8773521a111154e30ab0abe292d9f38d13e6;p=platform%2Fupstream%2Fdotnet%2Fruntime.git

Set BaseSize of interfaces to 0 (#89343)

We were computing these as the minimum object size. This number is meaningless because they don't get allocated on the GC heap. A zero compresses better. Surprisingly saves like 0.1% on Hello World despite being such an insignificant thing.
---

diff --git a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/EETypeNode.cs b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/EETypeNode.cs
index c3a5061..1e9f767 100644
--- a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/EETypeNode.cs
+++ b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/EETypeNode.cs
@@ -790,7 +790,13 @@ namespace ILCompiler.DependencyAnalysis
                 int pointerSize = _type.Context.Target.PointerSize;
                 int objectSize;
 
-                if (_type.IsDefType)
+                if (_type.IsInterface)
+                {
+                    // Interfaces don't live on the GC heap. Don't bother computing a number.
+                    // Zero compresses better than any useless number we would come up with.
+                    return 0;
+                }
+                else if (_type.IsDefType)
                 {
                     LayoutInt instanceByteCount = ((DefType)_type).InstanceByteCount;