[Support] computeHostNumPhysicalCores: use sched_getaffinity for all non-Android...

Make the sched_getaffinity based implementation available to all architectures
(except s390x/x86 which have a custom implementation). The `CPU_ALLOC(2048)`
code supports all `CONFIG_NR_CPUS` values in Linux kernel `arch/*/configs/`.

The function is mainly used by in-process ThinLTO to decide the default number
of threads. Returning -1 will use just one thread.

Android is excluded because of the higher API level requirement:
`sched_getaffinity; # introduced-arm=12 introduced-arm64=21 introduced-x86=12 introduced-x86_64=21`

diff --git a/llvm/lib/Support/Host.cpp b/llvm/lib/Support/Host.cpp
index f67acd7..f163c82 100644 (file)
--- a/llvm/lib/Support/Host.cpp
+++ b/llvm/lib/Support/Host.cpp
@@ -1586,7 +1586,9 @@ int computeHostNumPhysicalCores() {
   }
   return CPU_COUNT(&Enabled);
 }
-#elif defined(__linux__) && defined(__powerpc__)
+#elif defined(__linux__) && defined(__s390x__)
+int computeHostNumPhysicalCores() { return sysconf(_SC_NPROCESSORS_ONLN); }
+#elif defined(__linux__) && !defined(__ANDROID__)
 int computeHostNumPhysicalCores() {
   cpu_set_t Affinity;
   if (sched_getaffinity(0, sizeof(Affinity), &Affinity) == 0)
@@ -1605,8 +1607,6 @@ int computeHostNumPhysicalCores() {
   }
   return -1;
 }
-#elif defined(__linux__) && defined(__s390x__)
-int computeHostNumPhysicalCores() { return sysconf(_SC_NPROCESSORS_ONLN); }
 #elif defined(__APPLE__)
 // Gets the number of *physical cores* on the machine.
 int computeHostNumPhysicalCores() {