[libc++] Simplify definition of __libcpp_recursive_mutex_t

[hpoussin]

As it only depends of pointer size, use _WIN64 define to simplify conditions.

[llvmbot]

@llvm/pr-subscribers-libcxx

Author: Hervé Poussineau (hpoussin)

Changes

As it only depends of pointer size, use _WIN64 define to simplify conditions.

Original idea by @mstorsjo on #144272 (comment)

---

Full diff: https://github.com/llvm/llvm-project/pull/147385.diff

2 Files Affected:

• (modified) libcxx/include/__cxx03/__thread/support/windows.h (+2-4)
• (modified) libcxx/include/__thread/support/windows.h (+2-4)

diff --git a/libcxx/include/__cxx03/__thread/support/windows.h b/libcxx/include/__cxx03/__thread/support/windows.h
index 45252a57efaec..f9facbeefe4be 100644
--- a/libcxx/include/__cxx03/__thread/support/windows.h
+++ b/libcxx/include/__cxx03/__thread/support/windows.h
@@ -28,12 +28,10 @@ using __libcpp_timespec_t = ::timespec;
 typedef void* __libcpp_mutex_t;
 #define _LIBCPP_MUTEX_INITIALIZER 0
 
-#if defined(_M_IX86) || defined(__i386__) || defined(_M_ARM) || defined(__arm__)
-typedef void* __libcpp_recursive_mutex_t[6];
-#elif defined(_M_AMD64) || defined(__x86_64__) || defined(_M_ARM64) || defined(__aarch64__)
+#if defined(_WIN64)
 typedef void* __libcpp_recursive_mutex_t[5];
 #else
-#  error Unsupported architecture
+typedef void* __libcpp_recursive_mutex_t[6];
 #endif
 
 _LIBCPP_EXPORTED_FROM_ABI int __libcpp_recursive_mutex_init(__libcpp_recursive_mutex_t* __m);
diff --git a/libcxx/include/__thread/support/windows.h b/libcxx/include/__thread/support/windows.h
index 5dc4fa14f45b6..2921ed900e716 100644
--- a/libcxx/include/__thread/support/windows.h
+++ b/libcxx/include/__thread/support/windows.h
@@ -28,12 +28,10 @@ using __libcpp_timespec_t = ::timespec;
 typedef void* __libcpp_mutex_t;
 #define _LIBCPP_MUTEX_INITIALIZER 0
 
-#if defined(_M_IX86) || defined(__i386__) || defined(_M_ARM) || defined(__arm__)
-typedef void* __libcpp_recursive_mutex_t[6];
-#elif defined(_M_AMD64) || defined(__x86_64__) || defined(_M_ARM64) || defined(__aarch64__)
+#if defined(_WIN64)
 typedef void* __libcpp_recursive_mutex_t[5];
 #else
-#  error Unsupported architecture
+typedef void* __libcpp_recursive_mutex_t[6];
 #endif
 
 _LIBCPP_EXPORTED_FROM_ABI int __libcpp_recursive_mutex_init(__libcpp_recursive_mutex_t* __m);

[mstorsjo]

This looks reasonable to me, thanks! Btw, I'd prefer if you'd edit the commit message (the PR description) to omit the user name mention there (even though I appreciate the credit reference) - see https://discourse.llvm.org/t/forbidding-username-in-commits/86997.

[hpoussin]

This looks reasonable to me, thanks! Btw, I'd prefer if you'd edit the commit message (the PR description) to omit the user name mention there (even though I appreciate the credit reference) - see https://discourse.llvm.org/t/forbidding-username-in-commits/86997.

Removed your username in PR description.
It was not present in commit message.

[philnik777]

Mostly looks good. I like this approach a lot more than the old one. This doesn't mean we'll ever want to officially support a platform that hasn't been supported for like two decades, but I don't see a reason to not simplify our code. If that happens to make libc++ work on some platform I don't want to stay in the way of that.

[ldionne]

LGTM but I'd like @mstorsjo to stamp this.

[ldionne]

Ah, nevermind, @mstorsjo already saw this and was OK with the overall goal. Merging.