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40 
41 /*
42 //  Purpose:
43 //     Intel(R) Integrated Performance Primitives. Cryptography Primitives.
44 //     Unsigned internal BNU32 misc functionality
45 //
46 //  Contents:
47 //     cpNLZ_BNU32()
48 //
49 */
50 
51 #include "owncp.h"
52 #include "pcpbnuimpl.h"
53 #include "pcpbnumisc.h"
54 #include "pcpbnu32misc.h"
55 
56 /*F*
57 //    Name: cpNLZ_BNU32
58 //
59 // Purpose: Returns number of leading zeros of the 32-bit BN chunk.
60 //
61 // Returns:
62 //       number of leading zeros of the 32-bit BN chunk
63 //
64 // Parameters:
65 //    x         BigNum x
66 //
67 *F*/
68 
cpNLZ_BNU32(Ipp32u x)69 cpSize cpNLZ_BNU32(Ipp32u x)
70 {
71    cpSize nlz = BITSIZE(Ipp32u);
72    if(x) {
73       nlz = 0;
74       if( 0==(x & 0xFFFF0000) ) { nlz +=16; x<<=16; }
75       if( 0==(x & 0xFF000000) ) { nlz += 8; x<<= 8; }
76       if( 0==(x & 0xF0000000) ) { nlz += 4; x<<= 4; }
77       if( 0==(x & 0xC0000000) ) { nlz += 2; x<<= 2; }
78       if( 0==(x & 0x80000000) ) { nlz++; }
79    }
80    return nlz;
81 }
82