Address PR comment to use PreferredToolArchitecture

Author: savannahostrowski

.github/workflows/jit.yml

@@ -99,6 +99,7 @@ jobs:
         with:
           python-version: '3.11'
 
+      # test comment to trigger JIT CI
       # PCbuild downloads LLVM automatically:
       - name: Windows
         if: runner.os == 'Windows'

PCbuild/get_external.py

@@ -45,10 +45,11 @@ def fetch_zip(commit_hash, zip_dir, *, org='python', binary=False, verbose):
 
 
 def fetch_release(tag, tarball_dir, *, org='python', verbose=False):
-    arch = platform.machine()
-    # i686 (32-bit) builds can use x64 LLVM for cross-compilation
-    if arch == 'x86':
-        arch = 'AMD64'
+    # Use PreferredToolArchitecture if set, otherwise fall back to platform.machine()
+    arch = os.environ.get('PreferredToolArchitecture')
+    if not arch:
+        arch = platform.machine()
+    arch = {'AMD64': 'x64', 'x86': 'x64'}.get(arch, arch)
     reporthook = None
     if verbose:
         reporthook = print

Tools/jit/jit_infra.md

@@ -14,7 +14,7 @@ To update the LLVM release artifact for Windows builds, follow these steps:
    # For x86_64 (AMD64)
    tar -xf clang+llvm-21.1.4-x86_64-pc-windows-msvc.tar.xz
    mv clang+llvm-21.1.4-x86_64-pc-windows-msvc llvm-21.1.4.0
-   tar -cf - llvm-21.1.4.0 | pv | xz > llvm-21.1.4.0-AMD64.tar.xz
+   tar -cf - llvm-21.1.4.0 | pv | xz > llvm-21.1.4.0-x64.tar.xz
    rm -rf llvm-21.1.4.0
 
    # For ARM64
@@ -31,5 +31,5 @@ To update the LLVM release artifact for Windows builds, follow these steps:
 
 ### Other notes
 - You must make sure that the name of the artifact matches exactly what is expected in `Tools/jit/_llvm.py` and `PCbuild/get_externals.py`.
-- The artifact filename must include the architecture suffix (e.g. `llvm-21.1.4.0-AMD64.tar.xz`, `llvm-21.1.4.0-ARM64.tar.xz`).
+- The artifact filename must include the architecture suffix (e.g. `llvm-21.1.4.0-x64.tar.xz`, `llvm-21.1.4.0-ARM64.tar.xz`).
 - You must have permissions to create releases in the `cpython-bin-deps` repository. If you don't have permissions, you should contact one of the organization admins.