Optimization for 'n^2'

roberto-ieru · roberto-ieru · commit 9d067ab73b6b · 2020-11-13T09:59:07.000-03:00
Squares are much more common than other exponentiations, and 'n*n' is
much more efficient than 'pow'.
diff --git a/llimits.h b/llimits.h
@@ -326,7 +326,8 @@ typedef l_uint32 Instruction;
 
 /* exponentiation */
 #if !defined(luai_numpow)
-#define luai_numpow(L,a,b)      ((void)L, l_mathop(pow)(a,b))
+#define luai_numpow(L,a,b)  \
+  ((void)L, (b == 2) ? (a)*(a) : l_mathop(pow)(a,b))
 #endif
 
 /* the others are quite standard operations */
