Merge pull request #560 from czurnieden/mp_isone

Added macro mp_isone

Author: sjaeckel

doc/bn.tex

@@ -2658,6 +2658,12 @@ \section{Function Macros}
 \end{alltt}
 Checks if $a = 0$. It does not check if the amount of memory allocated for $a$ is also minimal.
 
+\index{mp\_isone}
+\begin{alltt}
+bool mp_isone(mp_int *a)
+\end{alltt}
+Checks if $a = 1$.
+
 Other macros which are either shortcuts to normal functions or just other names for them do have
 their place in a programmer's life, too!
 

tommath.h

@@ -208,6 +208,7 @@ mp_err mp_init_size(mp_int *a, int size) MP_WUR;
 
 /* ---> Basic Manipulations <--- */
 #define mp_iszero(a) ((a)->used == 0)
+#define mp_isone(a)  ( ((a)->sign == MP_ZPOS) && ((a)->used == 1u) && ((a)->dp[0] == 1u) )
 #define mp_isneg(a)  ((a)->sign == MP_NEG)
 #define mp_iseven(a) (((a)->used == 0) || (((a)->dp[0] & 1u) == 0u))
 #define mp_isodd(a)  (!mp_iseven(a))