Fix and improve coroutines for Darwin (macOS) ppc/ppc64. (#5975)

1 files changed, 21 insertions, 0 deletions

diff --git a/gc.c b/gc.c
index 7373bcfd67..ffc610dcc7 100644
--- a/gc.c
+++ b/gc.c
@@ -1359,6 +1359,27 @@ tick(void)
     return val;
 }
 
+/* Implementation for macOS PPC by @nobu
+ * See: https://github.com/ruby/ruby/pull/5975#discussion_r890045558
+ */
+#elif defined(__POWERPC__) && defined(__APPLE__)
+typedef unsigned long long tick_t;
+#define PRItick "llu"
+
+static __inline__ tick_t
+tick(void)
+{
+    unsigned long int upper, lower, tmp;
+    # define mftbu(r) __asm__ volatile("mftbu   %0" : "=r"(r))
+    # define mftb(r)  __asm__ volatile("mftb    %0" : "=r"(r))
+        do {
+            mftbu(upper);
+            mftb(lower);
+            mftbu(tmp);
+        } while (tmp != upper);
+    return ((tick_t)upper << 32) | lower;
+}
+
 #elif defined(__aarch64__) &&  defined(__GNUC__)
 typedef unsigned long tick_t;
 #define PRItick "lu"