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40
41 /*
42 // Purpose:
43 // Intel(R) Integrated Performance Primitives. Cryptography Primitives.
44 // Internal Unsigned BNU misc functionality
45 //
46 // Contents:
47 // cpMSBit_BNU()
48 //
49 */
50
51 #include "owncp.h"
52 #include "pcpbnumisc.h"
53
54 /*F*
55 // Name: cpMSBit_BNU
56 //
57 // Purpose: Returns Most Significant Bit of the BNU.
58 //
59 // Returns:
60 // Most Significant Bit of the BNU
61 //
62 // Parameters:
63 // pA BigNum A
64 // nsA size of A
65 //
66 // Note:
67 // if BNU==0, -1 will return
68 *F*/
69
cpMSBit_BNU(const BNU_CHUNK_T * pA,cpSize nsA)70 int cpMSBit_BNU(const BNU_CHUNK_T* pA, cpSize nsA)
71 {
72 int msb;
73 FIX_BNU(pA, nsA);
74 msb = nsA*BNU_CHUNK_BITS - cpNLZ_BNU(pA[nsA-1]) -1;
75 return msb;
76 }
77