Merge pull request #4549 from YosysHQ/emil/macos-max-mem-usage

driver: print maximum memory usage on macOS

kernel/driver.cc

@@ -721,13 +721,17 @@ int main(int argc, char **argv)
 			ru_buffer.ru_utime.tv_usec += ru_buffer_children.ru_utime.tv_usec;
 			ru_buffer.ru_stime.tv_sec += ru_buffer_children.ru_stime.tv_sec;
 			ru_buffer.ru_stime.tv_usec += ru_buffer_children.ru_stime.tv_usec;
-#if defined(__linux__) || defined(__FreeBSD__)
+#if defined(__linux__) || defined(__FreeBSD__) || defined(__APPLE__)
 			ru_buffer.ru_maxrss = std::max(ru_buffer.ru_maxrss, ru_buffer_children.ru_maxrss);
 #endif
 		}
 #if defined(__linux__) || defined(__FreeBSD__)
 		meminfo = stringf(", MEM: %.2f MB peak",
 				ru_buffer.ru_maxrss / 1024.0);
+#elif defined(__APPLE__)
+// https://stackoverflow.com/questions/59913657/strange-values-of-get-rusage-maxrss-on-macos-and-linux
+		meminfo = stringf(", MEM: %.2f MB peak",
+				ru_buffer.ru_maxrss / (1024.0 * 1024.0));
 #endif
 		log("End of script. Logfile hash: %s%sCPU: user %.2fs system %.2fs%s\n", hash.c_str(),
 				stats_divider.c_str(), ru_buffer.ru_utime.tv_sec + 1e-6 * ru_buffer.ru_utime.tv_usec,