[llvm] [llvm][docs] Note Windows on Arm setting in Visual Studio guide (PR #147710)

[David Spickett via llvm-commits]

https://github.com/DavidSpickett updated https://github.com/llvm/llvm-project/pull/147710

>From 5f389e15fd7de1acea2461368d7daa034f4270cf Mon Sep 17 00:00:00 2001
From: David Spickett <david.spickett at linaro.org>
Date: Wed, 9 Jul 2025 13:03:03 +0100
Subject: [PATCH] [llvm][docs] Note Windows on Arm setting in Visual Studio
 guide

As it very specifically wants ARM64 not what you'd guess which is
arm64.

This guide talks about VS2019 that probably has little or no
Windows on Arm support, but I don't have the bandwidth to follow
the whole thing and update it right now.

I think this small change will be enough for most people who
download the latest Visual Studio on a Windows on Arm machine.
---
 llvm/docs/GettingStartedVS.rst | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/llvm/docs/GettingStartedVS.rst b/llvm/docs/GettingStartedVS.rst
index bc5746df66e20..e65fd8fde829d 100644
--- a/llvm/docs/GettingStartedVS.rst
+++ b/llvm/docs/GettingStartedVS.rst
@@ -126,6 +126,15 @@ These instructions were tested with Visual Studio 2019 and Python 3.9.6:
        cmake -S llvm\llvm -B build -DLLVM_ENABLE_PROJECTS=clang -DLLVM_TARGETS_TO_BUILD=X86 -Thost=x64
        exit
 
+   .. note::
+     By default, the Visual Studio project files generated by CMake use the
+     32-bit toolset. If you are developing on a 64-bit version of Windows and
+     want to use the 64-bit toolset, pass the ``-Thost=x64`` flag when
+     generating the Visual Studio solution. This requires CMake 3.8.0 or later.
+
+     For Windows on Arm the equivalent is ``-Thost=ARM64``, but this the default
+     for those hosts, so you do not have to use this option.
+
    ``LLVM_ENABLE_PROJECTS`` specifies any additional LLVM projects you want to
    build while ``LLVM_TARGETS_TO_BUILD`` selects the compiler targets. If
    ``LLVM_TARGETS_TO_BUILD`` is omitted by default all targets are built
@@ -149,10 +158,6 @@ These instructions were tested with Visual Studio 2019 and Python 3.9.6:
    * CMake generates project files for all build types. To select a specific
      build type, use the Configuration manager from the VS IDE or the
      ``/property:Configuration`` command-line option when using MSBuild.
-   * By default, the Visual Studio project files generated by CMake use the
-     32-bit toolset. If you are developing on a 64-bit version of Windows and
-     want to use the 64-bit toolset, pass the ``-Thost=x64`` flag when
-     generating the Visual Studio solution. This requires CMake 3.8.0 or later.
 
 13. Start Visual Studio and select configuration: