Improve wiring macros

https://forum.pjrc.com/threads/27803-Serial-paresInt-not-working-as-expected-with-Teensy-3-1

teensy3/wiring.h

@@ -57,15 +57,36 @@ extern "C"{
 #undef abs
 #endif
 
-#define min(a,b) ((a)<(b)?(a):(b))
-#define max(a,b) ((a)>(b)?(a):(b))
-#define abs(x) ((x)>0?(x):-(x))
-#define constrain(amt,low,high) ((amt)<(low)?(low):((amt)>(high)?(high):(amt)))
-#define round(x)     ((x)>=0?(long)((x)+0.5):(long)((x)-0.5))
+#define min(a, b) ({ \
+  typeof(a) _a = (a); \
+  typeof(b) _b = (b); \
+  (_a < _b) ? _a : _b; \
+})
+#define max(a, b) ({ \
+  typeof(a) _a = (a); \
+  typeof(b) _b = (b); \
+  (_a > _b) ? _a : _b; \
+})
+#define abs(x) ({ \
+  typeof(x) _x = (x); \
+  (_x > 0) ? _x : -_x; \
+})
+#define constrain(amt, low, high) ({ \
+  typeof(amt) _amt = (amt); \
+  typeof(low) _low = (low); \
+  typeof(high) _high = (high); \
+  (_amt < _low) ? _low : ((_amt > _high) ? _high : _amt); \
+})
+#define round(x) ({ \
+  typeof(x) _x = (x); \
+  (_x>=0) ? (long)(_x+0.5) : (long)(_x-0.5); \
+})
 #define radians(deg) ((deg)*DEG_TO_RAD)
 #define degrees(rad) ((rad)*RAD_TO_DEG)
-#define sq(x) ((x)*(x))
-
+#define sq(x) ({ \
+  typeof(x) _x = (x); \
+  _x * _x; \
+})
 #define sei() __enable_irq()
 #define cli() __disable_irq()
 #define interrupts() __enable_irq()