From c9a31a6c499cc7629b3aca76bacf5ec2a6c4df45 Mon Sep 17 00:00:00 2001
From: Chuck Walbourn <walbourn@users.noreply.github.com>
Date: Fri, 2 Feb 2024 17:35:29 -0800
Subject: [PATCH] float_control pragma applies to clang (#183)

---
 Inc/DirectXMathMatrix.inl |  4 ++--
 Inc/DirectXMathVector.inl | 20 ++++++++++----------
 README.md                 |  4 ++++
 3 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/Inc/DirectXMathMatrix.inl b/Inc/DirectXMathMatrix.inl
index 1c579a1..f063a61 100644
--- a/Inc/DirectXMathMatrix.inl
+++ b/Inc/DirectXMathMatrix.inl
@@ -21,7 +21,7 @@
 
  //------------------------------------------------------------------------------
 
-#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__clang__) && !defined(__INTEL_COMPILER)
+#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__INTEL_COMPILER)
 #pragma float_control(push)
 #pragma float_control(precise, on)
 #endif
@@ -89,7 +89,7 @@ inline bool XM_CALLCONV XMMatrixIsNaN(FXMMATRIX M) noexcept
 #endif
 }
 
-#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__clang__) && !defined(__INTEL_COMPILER)
+#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__INTEL_COMPILER)
 #pragma float_control(pop)
 #endif
 
diff --git a/Inc/DirectXMathVector.inl b/Inc/DirectXMathVector.inl
index e3db56a..0394b37 100644
--- a/Inc/DirectXMathVector.inl
+++ b/Inc/DirectXMathVector.inl
@@ -2154,7 +2154,7 @@ inline XMVECTOR XM_CALLCONV XMVectorInBoundsR
 
 //------------------------------------------------------------------------------
 
-#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__clang__) && !defined(__INTEL_COMPILER)
+#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__INTEL_COMPILER)
 #pragma float_control(push)
 #pragma float_control(precise, on)
 #endif
@@ -2182,7 +2182,7 @@ inline XMVECTOR XM_CALLCONV XMVectorIsNaN(FXMVECTOR V) noexcept
 #endif
 }
 
-#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__clang__) && !defined(__INTEL_COMPILER)
+#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__INTEL_COMPILER)
 #pragma float_control(pop)
 #endif
 
@@ -2296,7 +2296,7 @@ namespace Internal
     }
 }
 
-#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__clang__) && !defined(__INTEL_COMPILER)
+#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__INTEL_COMPILER)
 #pragma float_control(push)
 #pragma float_control(precise, on)
 #endif
@@ -2341,7 +2341,7 @@ inline XMVECTOR XM_CALLCONV XMVectorRound(FXMVECTOR V) noexcept
 #endif
 }
 
-#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__clang__) && !defined(__INTEL_COMPILER)
+#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__INTEL_COMPILER)
 #pragma float_control(pop)
 #endif
 
@@ -6608,7 +6608,7 @@ inline bool XM_CALLCONV XMVector2InBounds
 
 //------------------------------------------------------------------------------
 
-#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__clang__) && !defined(__INTEL_COMPILER)
+#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__INTEL_COMPILER)
 #pragma float_control(push)
 #pragma float_control(precise, on)
 #endif
@@ -6632,7 +6632,7 @@ inline bool XM_CALLCONV XMVector2IsNaN(FXMVECTOR V) noexcept
 #endif
 }
 
-#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__clang__) && !defined(__INTEL_COMPILER)
+#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__INTEL_COMPILER)
 #pragma float_control(pop)
 #endif
 
@@ -9360,7 +9360,7 @@ inline bool XM_CALLCONV XMVector3InBounds
 
 //------------------------------------------------------------------------------
 
-#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__clang__) && !defined(__INTEL_COMPILER)
+#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__INTEL_COMPILER)
 #pragma float_control(push)
 #pragma float_control(precise, on)
 #endif
@@ -9388,7 +9388,7 @@ inline bool XM_CALLCONV XMVector3IsNaN(FXMVECTOR V) noexcept
 #endif
 }
 
-#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__clang__) && !defined(__INTEL_COMPILER)
+#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__INTEL_COMPILER)
 #pragma float_control(pop)
 #endif
 
@@ -13242,7 +13242,7 @@ inline bool XM_CALLCONV XMVector4InBounds
 
 //------------------------------------------------------------------------------
 
-#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__clang__) && !defined(__INTEL_COMPILER)
+#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__INTEL_COMPILER)
 #pragma float_control(push)
 #pragma float_control(precise, on)
 #endif
@@ -13269,7 +13269,7 @@ inline bool XM_CALLCONV XMVector4IsNaN(FXMVECTOR V) noexcept
 #endif
 }
 
-#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__clang__) && !defined(__INTEL_COMPILER)
+#if !defined(_XM_NO_INTRINSICS_) && defined(_MSC_VER) && !defined(__INTEL_COMPILER)
 #pragma float_control(pop)
 #endif
 
diff --git a/README.md b/README.md
index 02e5b17..4c3baa9 100644
--- a/README.md
+++ b/README.md
@@ -80,6 +80,10 @@ All content and source code for this package are subject to the terms of the [MI
 
 For the latest version of DirectXMath, bug reports, etc. please visit the project site on [GitHub](https://github.com/microsoft/DirectXMath).
 
+## Release Notes
+
+* The clang/LLVM toolset currently does not respect the ``float_control`` pragma for SSE instrinsics. Therefore, the use of ``/fp:fast`` is not recommended on clang/LLVM until this issue is fixed. See [55713](https://github.com/llvm/llvm-project/issues/55713).
+
 ## Support
 
 For questions, consider using [Stack Overflow](https://stackoverflow.com/questions/tagged/directxmath) with the *directxmath* tag, or the [DirectX Discord Server](https://discord.gg/directx) in the *dx12-developers* or *dx9-dx11-developers* channel.