From 89ec998d5b561a780defc1694c2f1b718b91d637 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 28 May 2026 00:29:13 +0000
Subject: [PATCH 1/3] Initial plan


From abd63f9b08305203778e215992af8c5f6a808a93 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 28 May 2026 00:42:58 +0000
Subject: [PATCH 2/3] Add disasm regression test for SingleToInt32Bits span
 loop codegen

Co-authored-by: steveisok <471438+steveisok@users.noreply.github.com>
---
 .../JitBlue/Runtime_130999/Runtime_130999.cs  | 38 +++++++++++++++++++
 .../Runtime_130999/Runtime_130999.csproj      | 21 ++++++++++
 2 files changed, 59 insertions(+)
 create mode 100644 src/tests/JIT/Regression/JitBlue/Runtime_130999/Runtime_130999.cs
 create mode 100644 src/tests/JIT/Regression/JitBlue/Runtime_130999/Runtime_130999.csproj

diff --git a/src/tests/JIT/Regression/JitBlue/Runtime_130999/Runtime_130999.cs b/src/tests/JIT/Regression/JitBlue/Runtime_130999/Runtime_130999.cs
new file mode 100644
index 00000000000000..a49293f1a7d9a2
--- /dev/null
+++ b/src/tests/JIT/Regression/JitBlue/Runtime_130999/Runtime_130999.cs
@@ -0,0 +1,38 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Runtime.CompilerServices;
+using Xunit;
+
+namespace Runtime_130999;
+
+public static class Runtime_130999
+{
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static int SumBits(Span<float> input)
+    {
+        int acc = 0;
+
+        foreach (float f in input)
+        {
+            if (f < 0)
+            {
+                acc++;
+            }
+
+            // X64-FULL-LINE: vmovd [[REG:[a-z0-9]+]], xmm{{[0-9]+}}
+            // X64-NOT: movss dword ptr [rsp
+            acc += BitConverter.SingleToInt32Bits(f);
+        }
+
+        return acc;
+    }
+
+    [Fact]
+    public static void TestEntryPoint()
+    {
+        float[] input = new[] { 1.25f, -2.5f, 3.75f, 4.125f };
+        Assert.Equal(11796481, SumBits(input));
+    }
+}
diff --git a/src/tests/JIT/Regression/JitBlue/Runtime_130999/Runtime_130999.csproj b/src/tests/JIT/Regression/JitBlue/Runtime_130999/Runtime_130999.csproj
new file mode 100644
index 00000000000000..5abc405b9fcdd8
--- /dev/null
+++ b/src/tests/JIT/Regression/JitBlue/Runtime_130999/Runtime_130999.csproj
@@ -0,0 +1,21 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <!-- Needed for CLRTestEnvironmentVariable -->
+    <RequiresProcessIsolation>true</RequiresProcessIsolation>
+  </PropertyGroup>
+  <PropertyGroup>
+    <Optimize>True</Optimize>
+    <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="$(MSBuildProjectName).cs">
+      <HasDisasmCheck>true</HasDisasmCheck>
+    </Compile>
+
+    <CLRTestEnvironmentVariable Include="DOTNET_TieredCompilation" Value="0" />
+    <CLRTestEnvironmentVariable Include="DOTNET_JITMinOpts" Value="0" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="$(TestLibraryProjectPath)" />
+  </ItemGroup>
+</Project>

From 28a3db19e321a5ad1bcbd4cdda119cbb69fe880f Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 28 May 2026 00:45:05 +0000
Subject: [PATCH 3/3] Refine SingleToInt32Bits disasm regression coverage

Co-authored-by: steveisok <471438+steveisok@users.noreply.github.com>
---
 .../JitBlue/Runtime_130999/Runtime_130999.cs  | 32 +++++++++++++++++--
 .../Runtime_130999/Runtime_130999.csproj      |  1 +
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/src/tests/JIT/Regression/JitBlue/Runtime_130999/Runtime_130999.cs b/src/tests/JIT/Regression/JitBlue/Runtime_130999/Runtime_130999.cs
index a49293f1a7d9a2..5b042dcb85e60d 100644
--- a/src/tests/JIT/Regression/JitBlue/Runtime_130999/Runtime_130999.cs
+++ b/src/tests/JIT/Regression/JitBlue/Runtime_130999/Runtime_130999.cs
@@ -9,6 +9,23 @@ namespace Runtime_130999;
 
 public static class Runtime_130999
 {
+    private static int Expected(float[] input)
+    {
+        int acc = 0;
+
+        foreach (float f in input)
+        {
+            if (f < 0)
+            {
+                acc++;
+            }
+
+            acc += BitConverter.SingleToInt32Bits(f);
+        }
+
+        return acc;
+    }
+
     [MethodImpl(MethodImplOptions.NoInlining)]
     private static int SumBits(Span<float> input)
     {
@@ -22,17 +39,26 @@ private static int SumBits(Span<float> input)
             }
 
             // X64-FULL-LINE: vmovd [[REG:[a-z0-9]+]], xmm{{[0-9]+}}
+            // X64-FULL-LINE-NEXT: add {{[a-z0-9]+}}, [[REG]]
             // X64-NOT: movss dword ptr [rsp
             acc += BitConverter.SingleToInt32Bits(f);
         }
 
+        // X64-FULL-LINE: ret
         return acc;
     }
 
     [Fact]
-    public static void TestEntryPoint()
+    public static void Test()
     {
-        float[] input = new[] { 1.25f, -2.5f, 3.75f, 4.125f };
-        Assert.Equal(11796481, SumBits(input));
+        float[] empty = Array.Empty<float>();
+        float[] single = new[] { -2.5f };
+        float[] mixed = new[] { 1.25f, -2.5f, 3.75f, 4.125f };
+        float[] edge = new[] { float.NaN, float.PositiveInfinity, float.NegativeInfinity, float.Epsilon, -float.Epsilon };
+
+        Assert.Equal(Expected(empty), SumBits(empty));
+        Assert.Equal(Expected(single), SumBits(single));
+        Assert.Equal(Expected(mixed), SumBits(mixed));
+        Assert.Equal(Expected(edge), SumBits(edge));
     }
 }
diff --git a/src/tests/JIT/Regression/JitBlue/Runtime_130999/Runtime_130999.csproj b/src/tests/JIT/Regression/JitBlue/Runtime_130999/Runtime_130999.csproj
index 5abc405b9fcdd8..a80dd6fcfafc78 100644
--- a/src/tests/JIT/Regression/JitBlue/Runtime_130999/Runtime_130999.csproj
+++ b/src/tests/JIT/Regression/JitBlue/Runtime_130999/Runtime_130999.csproj
@@ -9,6 +9,7 @@
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="$(MSBuildProjectName).cs">
+      <!-- Enable FileCheck verification of X64-* disasm directives in the test source. -->
       <HasDisasmCheck>true</HasDisasmCheck>
     </Compile>