From 50e8affb5bcb3f6a50a223053fc92145a5709e82 Mon Sep 17 00:00:00 2001
From: Niyas Sait <niyas.sait@linaro.org>
Date: Fri, 16 Dec 2022 10:45:56 +0000
Subject: [PATCH v7] Enable postgres native build for windows-arm64 platform

- Add support for meson build
- Add arm64 definition of spin_delay function
- Exclude arm_acle.h import for MSVC
---
 doc/src/sgml/install-windows.sgml |  3 ++-
 meson.build                       | 33 +++++++++++++++++++------------
 src/include/storage/s_lock.h      | 20 +++++++++++++++++--
 src/port/pg_crc32c_armv8.c        |  2 ++
 src/tools/msvc/gendef.pl          |  8 ++++----
 5 files changed, 46 insertions(+), 20 deletions(-)

diff --git a/doc/src/sgml/install-windows.sgml b/doc/src/sgml/install-windows.sgml
index bbd4960e7b..3f865d7d3b 100644
--- a/doc/src/sgml/install-windows.sgml
+++ b/doc/src/sgml/install-windows.sgml
@@ -352,7 +352,8 @@ $ENV{MSBFLAGS}="/m";
   <title>Special Considerations for 64-Bit Windows</title>
 
   <para>
-   PostgreSQL will only build for the x64 architecture on 64-bit Windows.
+   PostgreSQL will only build for the x64 and ARM64 architectures on 64-bit
+   Windows.
   </para>
 
   <para>
diff --git a/meson.build b/meson.build
index 725e10d815..e354ad7650 100644
--- a/meson.build
+++ b/meson.build
@@ -1944,7 +1944,13 @@ int main(void)
 
 elif host_cpu == 'arm' or host_cpu == 'aarch64'
 
-  prog = '''
+  if cc.get_id() == 'msvc'
+    cdata.set('USE_ARMV8_CRC32C', false)
+    cdata.set('USE_ARMV8_CRC32C_WITH_RUNTIME_CHECK', 1)
+    have_optimized_crc = true
+  else
+
+    prog = '''
 #include <arm_acle.h>
 
 int main(void)
@@ -1960,18 +1966,19 @@ int main(void)
 }
 '''
 
-  if cc.links(prog, name: '__crc32cb, __crc32ch, __crc32cw, and __crc32cd without -march=armv8-a+crc',
-      args: test_c_args)
-    # Use ARM CRC Extension unconditionally
-    cdata.set('USE_ARMV8_CRC32C', 1)
-    have_optimized_crc = true
-  elif cc.links(prog, name: '__crc32cb, __crc32ch, __crc32cw, and __crc32cd with -march=armv8-a+crc',
-      args: test_c_args + ['-march=armv8-a+crc'])
-    # Use ARM CRC Extension, with runtime check
-    cflags_crc += '-march=armv8-a+crc'
-    cdata.set('USE_ARMV8_CRC32C', false)
-    cdata.set('USE_ARMV8_CRC32C_WITH_RUNTIME_CHECK', 1)
-    have_optimized_crc = true
+    if cc.links(prog, name: '__crc32cb, __crc32ch, __crc32cw, and __crc32cd without -march=armv8-a+crc',
+        args: test_c_args)
+      # Use ARM CRC Extension unconditionally
+      cdata.set('USE_ARMV8_CRC32C', 1)
+      have_optimized_crc = true
+    elif cc.links(prog, name: '__crc32cb, __crc32ch, __crc32cw, and __crc32cd with -march=armv8-a+crc',
+        args: test_c_args + ['-march=armv8-a+crc'])
+      # Use ARM CRC Extension, with runtime check
+      cflags_crc += '-march=armv8-a+crc'
+      cdata.set('USE_ARMV8_CRC32C', false)
+      cdata.set('USE_ARMV8_CRC32C_WITH_RUNTIME_CHECK', 1)
+      have_optimized_crc = true
+    endif
   endif
 endif
 
diff --git a/src/include/storage/s_lock.h b/src/include/storage/s_lock.h
index 8b19ab160f..94d2380393 100644
--- a/src/include/storage/s_lock.h
+++ b/src/include/storage/s_lock.h
@@ -707,15 +707,31 @@ typedef LONG slock_t;
 
 #define SPIN_DELAY() spin_delay()
 
-/* If using Visual C++ on Win64, inline assembly is unavailable.
- * Use a _mm_pause intrinsic instead of rep nop.
+/*
+ * If using Visual C++ on Win64, inline assembly is unavailable.
+ * Use architecture specific intrinsics.
  */
 #if defined(_WIN64)
+/*
+ * For Arm64, use __isb intrinsic. See aarch64 inline assembly definition for details.
+ */
+#ifdef _M_ARM64
+static __forceinline void
+spin_delay(void)
+{
+	 /* Reference: https://learn.microsoft.com/en-us/cpp/intrinsics/arm64-intrinsics#BarrierRestrictions */
+	__isb(_ARM64_BARRIER_SY);
+}
+#else
+/*
+ * For x64, use _mm_pause intrinsic instead of rep nop.
+ */
 static __forceinline void
 spin_delay(void)
 {
 	_mm_pause();
 }
+#endif
 #else
 static __forceinline void
 spin_delay(void)
diff --git a/src/port/pg_crc32c_armv8.c b/src/port/pg_crc32c_armv8.c
index 9e301f96f6..981718752f 100644
--- a/src/port/pg_crc32c_armv8.c
+++ b/src/port/pg_crc32c_armv8.c
@@ -14,7 +14,9 @@
  */
 #include "c.h"
 
+#ifndef _MSC_VER
 #include <arm_acle.h>
+#endif
 
 #include "port/pg_crc32c.h"
 
diff --git a/src/tools/msvc/gendef.pl b/src/tools/msvc/gendef.pl
index d6bed1ce15..4882d37faf 100644
--- a/src/tools/msvc/gendef.pl
+++ b/src/tools/msvc/gendef.pl
@@ -120,9 +120,9 @@ sub writedef
 	{
 		my $isdata = $def->{$f} eq 'data';
 
-		# Strip the leading underscore for win32, but not x64
+		# Strip the leading underscore for win32, but not x64 and aarch64
 		$f =~ s/^_//
-		  unless ($arch eq "x86_64");
+		  unless ($arch eq "x86_64" || $arch eq "aarch64");
 
 		# Emit just the name if it's a function symbol, or emit the name
 		# decorated with the DATA option for variables.
@@ -143,7 +143,7 @@ sub writedef
 sub usage
 {
 	die("Usage: gendef.pl --arch <arch> --deffile <deffile> --tempdir <tempdir> files-or-directories\n"
-		  . "    arch: x86 | x86_64\n"
+		  . "    arch: x86 | x86_64 | aarch64\n"
 		  . "    deffile: path of the generated file\n"
 		  . "    tempdir: directory for temporary files\n"
 		  . "    files or directories: object files or directory containing object files\n"
@@ -160,7 +160,7 @@ GetOptions(
 	'tempdir:s' => \$tempdir,) or usage();
 
 usage("arch: $arch")
-  unless ($arch eq 'x86' || $arch eq 'x86_64');
+  unless ($arch eq 'x86' || $arch eq 'x86_64' || $arch eq 'aarch64');
 
 my @files;
 
-- 
2.38.1.windows.1