add s32int, s64int, s16int
diff --git a/include/u.h b/include/u.h
index 4716ce4..515072c 100644
--- a/include/u.h
+++ b/include/u.h
@@ -64,6 +64,8 @@
 
 typedef signed char schar;
 typedef unsigned int u32int;
+typedef int s32int;
+
 #ifdef _NEEDUCHAR
 	typedef unsigned char uchar;
 #endif
@@ -79,8 +81,11 @@
 typedef unsigned long long uvlong;
 typedef long long vlong;
 typedef uvlong u64int;
+typedef vlong s64int;
 typedef uchar u8int;
+typedef schar s8int;
 typedef ushort u16int;
+typedef short s16int;
 
 #undef _NEEDUCHAR
 #undef _NEEDUSHORT