From 92d70f4167222b5d61728d9443e8d72207e96d50 Mon Sep 17 00:00:00 2001
From: nia <nia@NetBSD.org>
Date: Sun, 12 Nov 2023 20:22:23 +0100
Subject: [PATCH] cpuinfo: Fix detection of physical memory above 2GB on NetBSD

Rework the code to clearly prefer 64-bit sysctls first, then
legacy sysctls, and eliminate a second ifdef.

Signed-off-by: Nia Alarie <nia@NetBSD.org>
(cherry picked from commit 69cae07cc1c216e35ddf3df98048378ad7aeaf92)
---
 src/cpuinfo/SDL_cpuinfo.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/src/cpuinfo/SDL_cpuinfo.c b/src/cpuinfo/SDL_cpuinfo.c
index bdc6b3e0b..c5f1eb4a6 100644
--- a/src/cpuinfo/SDL_cpuinfo.c
+++ b/src/cpuinfo/SDL_cpuinfo.c
@@ -1079,16 +1079,19 @@ int SDL_GetSystemRAM(void)
 #endif
 #ifdef HAVE_SYSCTLBYNAME
         if (SDL_SystemRAM <= 0) {
-#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__NetBSD__) || defined(__DragonFly__)
-#ifdef HW_REALMEM
+#ifdef HW_PHYSMEM64
+            /* (64-bit): NetBSD since 2003, OpenBSD */
+            int mib[2] = { CTL_HW, HW_PHYSMEM64 };
+#elif defined(HW_REALMEM)
+            /* (64-bit): FreeBSD since 2005, DragonFly */
             int mib[2] = { CTL_HW, HW_REALMEM };
-#else
-            /* might only report up to 2 GiB */
-            int mib[2] = { CTL_HW, HW_PHYSMEM };
-#endif /* HW_REALMEM */
-#else
+#elif defined(HW_MEMSIZE)
+            /* (64-bit): Darwin */
             int mib[2] = { CTL_HW, HW_MEMSIZE };
-#endif /* __FreeBSD__ || __FreeBSD_kernel__ */
+#else
+            /* (32-bit): very old BSD, might only report up to 2 GiB */
+            int mib[2] = { CTL_HW, HW_PHYSMEM };
+#endif /* HW_PHYSMEM64 */
             Uint64 memsize = 0;
             size_t len = sizeof(memsize);