|  | 
 | /* | 
 | =============================================================================== | 
 |  | 
 | This C source fragment is part of the SoftFloat IEC/IEEE Floating-point | 
 | Arithmetic Package, Release 2. | 
 |  | 
 | Written by John R. Hauser.  This work was made possible in part by the | 
 | International Computer Science Institute, located at Suite 600, 1947 Center | 
 | Street, Berkeley, California 94704.  Funding was partially provided by the | 
 | National Science Foundation under grant MIP-9311980.  The original version | 
 | of this code was written as part of a project to build a fixed-point vector | 
 | processor in collaboration with the University of California at Berkeley, | 
 | overseen by Profs. Nelson Morgan and John Wawrzynek.  More information | 
 | is available through the web page `http://HTTP.CS.Berkeley.EDU/~jhauser/ | 
 | arithmetic/softfloat.html'. | 
 |  | 
 | THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE.  Although reasonable effort | 
 | has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT | 
 | TIMES RESULT IN INCORRECT BEHAVIOR.  USE OF THIS SOFTWARE IS RESTRICTED TO | 
 | PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY | 
 | AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE. | 
 |  | 
 | Derivative works are acceptable, even for commercial purposes, so long as | 
 | (1) they include prominent notice that the work is derivative, and (2) they | 
 | include prominent notice akin to these three paragraphs for those parts of | 
 | this code that are retained. | 
 |  | 
 | =============================================================================== | 
 | */ | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Shifts `a' right by the number of bits given in `count'.  If any nonzero | 
 | bits are shifted off, they are ``jammed'' into the least significant bit of | 
 | the result by setting the least significant bit to 1.  The value of `count' | 
 | can be arbitrarily large; in particular, if `count' is greater than 32, the | 
 | result will be either 0 or 1, depending on whether `a' is zero or nonzero. | 
 | The result is stored in the location pointed to by `zPtr'. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE void shift32RightJamming( bits32 a, int16 count, bits32 *zPtr ) | 
 | { | 
 |     bits32 z; | 
 |     if ( count == 0 ) { | 
 |         z = a; | 
 |     } | 
 |     else if ( count < 32 ) { | 
 |         z = ( a>>count ) | ( ( a<<( ( - count ) & 31 ) ) != 0 ); | 
 |     } | 
 |     else { | 
 |         z = ( a != 0 ); | 
 |     } | 
 |     *zPtr = z; | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Shifts `a' right by the number of bits given in `count'.  If any nonzero | 
 | bits are shifted off, they are ``jammed'' into the least significant bit of | 
 | the result by setting the least significant bit to 1.  The value of `count' | 
 | can be arbitrarily large; in particular, if `count' is greater than 64, the | 
 | result will be either 0 or 1, depending on whether `a' is zero or nonzero. | 
 | The result is stored in the location pointed to by `zPtr'. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE void shift64RightJamming( bits64 a, int16 count, bits64 *zPtr ) | 
 | { | 
 |     bits64 z; | 
 |  | 
 |  __asm__("@shift64RightJamming -- start");    | 
 |     if ( count == 0 ) { | 
 |         z = a; | 
 |     } | 
 |     else if ( count < 64 ) { | 
 |         z = ( a>>count ) | ( ( a<<( ( - count ) & 63 ) ) != 0 ); | 
 |     } | 
 |     else { | 
 |         z = ( a != 0 ); | 
 |     } | 
 |  __asm__("@shift64RightJamming -- end");    | 
 |     *zPtr = z; | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Shifts the 128-bit value formed by concatenating `a0' and `a1' right by 64 | 
 | _plus_ the number of bits given in `count'.  The shifted result is at most | 
 | 64 nonzero bits; this is stored at the location pointed to by `z0Ptr'.  The | 
 | bits shifted off form a second 64-bit result as follows:  The _last_ bit | 
 | shifted off is the most-significant bit of the extra result, and the other | 
 | 63 bits of the extra result are all zero if and only if _all_but_the_last_ | 
 | bits shifted off were all zero.  This extra result is stored in the location | 
 | pointed to by `z1Ptr'.  The value of `count' can be arbitrarily large. | 
 |     (This routine makes more sense if `a0' and `a1' are considered to form a | 
 | fixed-point value with binary point between `a0' and `a1'.  This fixed-point | 
 | value is shifted right by the number of bits given in `count', and the | 
 | integer part of the result is returned at the location pointed to by | 
 | `z0Ptr'.  The fractional part of the result may be slightly corrupted as | 
 | described above, and is returned at the location pointed to by `z1Ptr'.) | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE void | 
 |  shift64ExtraRightJamming( | 
 |      bits64 a0, bits64 a1, int16 count, bits64 *z0Ptr, bits64 *z1Ptr ) | 
 | { | 
 |     bits64 z0, z1; | 
 |     int8 negCount = ( - count ) & 63; | 
 |  | 
 |     if ( count == 0 ) { | 
 |         z1 = a1; | 
 |         z0 = a0; | 
 |     } | 
 |     else if ( count < 64 ) { | 
 |         z1 = ( a0<<negCount ) | ( a1 != 0 ); | 
 |         z0 = a0>>count; | 
 |     } | 
 |     else { | 
 |         if ( count == 64 ) { | 
 |             z1 = a0 | ( a1 != 0 ); | 
 |         } | 
 |         else { | 
 |             z1 = ( ( a0 | a1 ) != 0 ); | 
 |         } | 
 |         z0 = 0; | 
 |     } | 
 |     *z1Ptr = z1; | 
 |     *z0Ptr = z0; | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Shifts the 128-bit value formed by concatenating `a0' and `a1' right by the | 
 | number of bits given in `count'.  Any bits shifted off are lost.  The value | 
 | of `count' can be arbitrarily large; in particular, if `count' is greater | 
 | than 128, the result will be 0.  The result is broken into two 64-bit pieces | 
 | which are stored at the locations pointed to by `z0Ptr' and `z1Ptr'. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE void | 
 |  shift128Right( | 
 |      bits64 a0, bits64 a1, int16 count, bits64 *z0Ptr, bits64 *z1Ptr ) | 
 | { | 
 |     bits64 z0, z1; | 
 |     int8 negCount = ( - count ) & 63; | 
 |  | 
 |     if ( count == 0 ) { | 
 |         z1 = a1; | 
 |         z0 = a0; | 
 |     } | 
 |     else if ( count < 64 ) { | 
 |         z1 = ( a0<<negCount ) | ( a1>>count ); | 
 |         z0 = a0>>count; | 
 |     } | 
 |     else { | 
 |         z1 = ( count < 64 ) ? ( a0>>( count & 63 ) ) : 0; | 
 |         z0 = 0; | 
 |     } | 
 |     *z1Ptr = z1; | 
 |     *z0Ptr = z0; | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Shifts the 128-bit value formed by concatenating `a0' and `a1' right by the | 
 | number of bits given in `count'.  If any nonzero bits are shifted off, they | 
 | are ``jammed'' into the least significant bit of the result by setting the | 
 | least significant bit to 1.  The value of `count' can be arbitrarily large; | 
 | in particular, if `count' is greater than 128, the result will be either 0 | 
 | or 1, depending on whether the concatenation of `a0' and `a1' is zero or | 
 | nonzero.  The result is broken into two 64-bit pieces which are stored at | 
 | the locations pointed to by `z0Ptr' and `z1Ptr'. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE void | 
 |  shift128RightJamming( | 
 |      bits64 a0, bits64 a1, int16 count, bits64 *z0Ptr, bits64 *z1Ptr ) | 
 | { | 
 |     bits64 z0, z1; | 
 |     int8 negCount = ( - count ) & 63; | 
 |  | 
 |     if ( count == 0 ) { | 
 |         z1 = a1; | 
 |         z0 = a0; | 
 |     } | 
 |     else if ( count < 64 ) { | 
 |         z1 = ( a0<<negCount ) | ( a1>>count ) | ( ( a1<<negCount ) != 0 ); | 
 |         z0 = a0>>count; | 
 |     } | 
 |     else { | 
 |         if ( count == 64 ) { | 
 |             z1 = a0 | ( a1 != 0 ); | 
 |         } | 
 |         else if ( count < 128 ) { | 
 |             z1 = ( a0>>( count & 63 ) ) | ( ( ( a0<<negCount ) | a1 ) != 0 ); | 
 |         } | 
 |         else { | 
 |             z1 = ( ( a0 | a1 ) != 0 ); | 
 |         } | 
 |         z0 = 0; | 
 |     } | 
 |     *z1Ptr = z1; | 
 |     *z0Ptr = z0; | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Shifts the 192-bit value formed by concatenating `a0', `a1', and `a2' right | 
 | by 64 _plus_ the number of bits given in `count'.  The shifted result is | 
 | at most 128 nonzero bits; these are broken into two 64-bit pieces which are | 
 | stored at the locations pointed to by `z0Ptr' and `z1Ptr'.  The bits shifted | 
 | off form a third 64-bit result as follows:  The _last_ bit shifted off is | 
 | the most-significant bit of the extra result, and the other 63 bits of the | 
 | extra result are all zero if and only if _all_but_the_last_ bits shifted off | 
 | were all zero.  This extra result is stored in the location pointed to by | 
 | `z2Ptr'.  The value of `count' can be arbitrarily large. | 
 |     (This routine makes more sense if `a0', `a1', and `a2' are considered | 
 | to form a fixed-point value with binary point between `a1' and `a2'.  This | 
 | fixed-point value is shifted right by the number of bits given in `count', | 
 | and the integer part of the result is returned at the locations pointed to | 
 | by `z0Ptr' and `z1Ptr'.  The fractional part of the result may be slightly | 
 | corrupted as described above, and is returned at the location pointed to by | 
 | `z2Ptr'.) | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE void | 
 |  shift128ExtraRightJamming( | 
 |      bits64 a0, | 
 |      bits64 a1, | 
 |      bits64 a2, | 
 |      int16 count, | 
 |      bits64 *z0Ptr, | 
 |      bits64 *z1Ptr, | 
 |      bits64 *z2Ptr | 
 |  ) | 
 | { | 
 |     bits64 z0, z1, z2; | 
 |     int8 negCount = ( - count ) & 63; | 
 |  | 
 |     if ( count == 0 ) { | 
 |         z2 = a2; | 
 |         z1 = a1; | 
 |         z0 = a0; | 
 |     } | 
 |     else { | 
 |         if ( count < 64 ) { | 
 |             z2 = a1<<negCount; | 
 |             z1 = ( a0<<negCount ) | ( a1>>count ); | 
 |             z0 = a0>>count; | 
 |         } | 
 |         else { | 
 |             if ( count == 64 ) { | 
 |                 z2 = a1; | 
 |                 z1 = a0; | 
 |             } | 
 |             else { | 
 |                 a2 |= a1; | 
 |                 if ( count < 128 ) { | 
 |                     z2 = a0<<negCount; | 
 |                     z1 = a0>>( count & 63 ); | 
 |                 } | 
 |                 else { | 
 |                     z2 = ( count == 128 ) ? a0 : ( a0 != 0 ); | 
 |                     z1 = 0; | 
 |                 } | 
 |             } | 
 |             z0 = 0; | 
 |         } | 
 |         z2 |= ( a2 != 0 ); | 
 |     } | 
 |     *z2Ptr = z2; | 
 |     *z1Ptr = z1; | 
 |     *z0Ptr = z0; | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Shifts the 128-bit value formed by concatenating `a0' and `a1' left by the | 
 | number of bits given in `count'.  Any bits shifted off are lost.  The value | 
 | of `count' must be less than 64.  The result is broken into two 64-bit | 
 | pieces which are stored at the locations pointed to by `z0Ptr' and `z1Ptr'. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE void | 
 |  shortShift128Left( | 
 |      bits64 a0, bits64 a1, int16 count, bits64 *z0Ptr, bits64 *z1Ptr ) | 
 | { | 
 |  | 
 |     *z1Ptr = a1<<count; | 
 |     *z0Ptr = | 
 |         ( count == 0 ) ? a0 : ( a0<<count ) | ( a1>>( ( - count ) & 63 ) ); | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Shifts the 192-bit value formed by concatenating `a0', `a1', and `a2' left | 
 | by the number of bits given in `count'.  Any bits shifted off are lost. | 
 | The value of `count' must be less than 64.  The result is broken into three | 
 | 64-bit pieces which are stored at the locations pointed to by `z0Ptr', | 
 | `z1Ptr', and `z2Ptr'. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE void | 
 |  shortShift192Left( | 
 |      bits64 a0, | 
 |      bits64 a1, | 
 |      bits64 a2, | 
 |      int16 count, | 
 |      bits64 *z0Ptr, | 
 |      bits64 *z1Ptr, | 
 |      bits64 *z2Ptr | 
 |  ) | 
 | { | 
 |     bits64 z0, z1, z2; | 
 |     int8 negCount; | 
 |  | 
 |     z2 = a2<<count; | 
 |     z1 = a1<<count; | 
 |     z0 = a0<<count; | 
 |     if ( 0 < count ) { | 
 |         negCount = ( ( - count ) & 63 ); | 
 |         z1 |= a2>>negCount; | 
 |         z0 |= a1>>negCount; | 
 |     } | 
 |     *z2Ptr = z2; | 
 |     *z1Ptr = z1; | 
 |     *z0Ptr = z0; | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Adds the 128-bit value formed by concatenating `a0' and `a1' to the 128-bit | 
 | value formed by concatenating `b0' and `b1'.  Addition is modulo 2^128, so | 
 | any carry out is lost.  The result is broken into two 64-bit pieces which | 
 | are stored at the locations pointed to by `z0Ptr' and `z1Ptr'. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE void | 
 |  add128( | 
 |      bits64 a0, bits64 a1, bits64 b0, bits64 b1, bits64 *z0Ptr, bits64 *z1Ptr ) | 
 | { | 
 |     bits64 z1; | 
 |  | 
 |     z1 = a1 + b1; | 
 |     *z1Ptr = z1; | 
 |     *z0Ptr = a0 + b0 + ( z1 < a1 ); | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Adds the 192-bit value formed by concatenating `a0', `a1', and `a2' to the | 
 | 192-bit value formed by concatenating `b0', `b1', and `b2'.  Addition is | 
 | modulo 2^192, so any carry out is lost.  The result is broken into three | 
 | 64-bit pieces which are stored at the locations pointed to by `z0Ptr', | 
 | `z1Ptr', and `z2Ptr'. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE void | 
 |  add192( | 
 |      bits64 a0, | 
 |      bits64 a1, | 
 |      bits64 a2, | 
 |      bits64 b0, | 
 |      bits64 b1, | 
 |      bits64 b2, | 
 |      bits64 *z0Ptr, | 
 |      bits64 *z1Ptr, | 
 |      bits64 *z2Ptr | 
 |  ) | 
 | { | 
 |     bits64 z0, z1, z2; | 
 |     int8 carry0, carry1; | 
 |  | 
 |     z2 = a2 + b2; | 
 |     carry1 = ( z2 < a2 ); | 
 |     z1 = a1 + b1; | 
 |     carry0 = ( z1 < a1 ); | 
 |     z0 = a0 + b0; | 
 |     z1 += carry1; | 
 |     z0 += ( z1 < carry1 ); | 
 |     z0 += carry0; | 
 |     *z2Ptr = z2; | 
 |     *z1Ptr = z1; | 
 |     *z0Ptr = z0; | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Subtracts the 128-bit value formed by concatenating `b0' and `b1' from the | 
 | 128-bit value formed by concatenating `a0' and `a1'.  Subtraction is modulo | 
 | 2^128, so any borrow out (carry out) is lost.  The result is broken into two | 
 | 64-bit pieces which are stored at the locations pointed to by `z0Ptr' and | 
 | `z1Ptr'. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE void | 
 |  sub128( | 
 |      bits64 a0, bits64 a1, bits64 b0, bits64 b1, bits64 *z0Ptr, bits64 *z1Ptr ) | 
 | { | 
 |  | 
 |     *z1Ptr = a1 - b1; | 
 |     *z0Ptr = a0 - b0 - ( a1 < b1 ); | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Subtracts the 192-bit value formed by concatenating `b0', `b1', and `b2' | 
 | from the 192-bit value formed by concatenating `a0', `a1', and `a2'. | 
 | Subtraction is modulo 2^192, so any borrow out (carry out) is lost.  The | 
 | result is broken into three 64-bit pieces which are stored at the locations | 
 | pointed to by `z0Ptr', `z1Ptr', and `z2Ptr'. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE void | 
 |  sub192( | 
 |      bits64 a0, | 
 |      bits64 a1, | 
 |      bits64 a2, | 
 |      bits64 b0, | 
 |      bits64 b1, | 
 |      bits64 b2, | 
 |      bits64 *z0Ptr, | 
 |      bits64 *z1Ptr, | 
 |      bits64 *z2Ptr | 
 |  ) | 
 | { | 
 |     bits64 z0, z1, z2; | 
 |     int8 borrow0, borrow1; | 
 |  | 
 |     z2 = a2 - b2; | 
 |     borrow1 = ( a2 < b2 ); | 
 |     z1 = a1 - b1; | 
 |     borrow0 = ( a1 < b1 ); | 
 |     z0 = a0 - b0; | 
 |     z0 -= ( z1 < borrow1 ); | 
 |     z1 -= borrow1; | 
 |     z0 -= borrow0; | 
 |     *z2Ptr = z2; | 
 |     *z1Ptr = z1; | 
 |     *z0Ptr = z0; | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Multiplies `a' by `b' to obtain a 128-bit product.  The product is broken | 
 | into two 64-bit pieces which are stored at the locations pointed to by | 
 | `z0Ptr' and `z1Ptr'. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE void mul64To128( bits64 a, bits64 b, bits64 *z0Ptr, bits64 *z1Ptr ) | 
 | { | 
 |     bits32 aHigh, aLow, bHigh, bLow; | 
 |     bits64 z0, zMiddleA, zMiddleB, z1; | 
 |  | 
 |     aLow = a; | 
 |     aHigh = a>>32; | 
 |     bLow = b; | 
 |     bHigh = b>>32; | 
 |     z1 = ( (bits64) aLow ) * bLow; | 
 |     zMiddleA = ( (bits64) aLow ) * bHigh; | 
 |     zMiddleB = ( (bits64) aHigh ) * bLow; | 
 |     z0 = ( (bits64) aHigh ) * bHigh; | 
 |     zMiddleA += zMiddleB; | 
 |     z0 += ( ( (bits64) ( zMiddleA < zMiddleB ) )<<32 ) + ( zMiddleA>>32 ); | 
 |     zMiddleA <<= 32; | 
 |     z1 += zMiddleA; | 
 |     z0 += ( z1 < zMiddleA ); | 
 |     *z1Ptr = z1; | 
 |     *z0Ptr = z0; | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Multiplies the 128-bit value formed by concatenating `a0' and `a1' by `b' to | 
 | obtain a 192-bit product.  The product is broken into three 64-bit pieces | 
 | which are stored at the locations pointed to by `z0Ptr', `z1Ptr', and | 
 | `z2Ptr'. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE void | 
 |  mul128By64To192( | 
 |      bits64 a0, | 
 |      bits64 a1, | 
 |      bits64 b, | 
 |      bits64 *z0Ptr, | 
 |      bits64 *z1Ptr, | 
 |      bits64 *z2Ptr | 
 |  ) | 
 | { | 
 |     bits64 z0, z1, z2, more1; | 
 |  | 
 |     mul64To128( a1, b, &z1, &z2 ); | 
 |     mul64To128( a0, b, &z0, &more1 ); | 
 |     add128( z0, more1, 0, z1, &z0, &z1 ); | 
 |     *z2Ptr = z2; | 
 |     *z1Ptr = z1; | 
 |     *z0Ptr = z0; | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Multiplies the 128-bit value formed by concatenating `a0' and `a1' to the | 
 | 128-bit value formed by concatenating `b0' and `b1' to obtain a 256-bit | 
 | product.  The product is broken into four 64-bit pieces which are stored at | 
 | the locations pointed to by `z0Ptr', `z1Ptr', `z2Ptr', and `z3Ptr'. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE void | 
 |  mul128To256( | 
 |      bits64 a0, | 
 |      bits64 a1, | 
 |      bits64 b0, | 
 |      bits64 b1, | 
 |      bits64 *z0Ptr, | 
 |      bits64 *z1Ptr, | 
 |      bits64 *z2Ptr, | 
 |      bits64 *z3Ptr | 
 |  ) | 
 | { | 
 |     bits64 z0, z1, z2, z3; | 
 |     bits64 more1, more2; | 
 |  | 
 |     mul64To128( a1, b1, &z2, &z3 ); | 
 |     mul64To128( a1, b0, &z1, &more2 ); | 
 |     add128( z1, more2, 0, z2, &z1, &z2 ); | 
 |     mul64To128( a0, b0, &z0, &more1 ); | 
 |     add128( z0, more1, 0, z1, &z0, &z1 ); | 
 |     mul64To128( a0, b1, &more1, &more2 ); | 
 |     add128( more1, more2, 0, z2, &more1, &z2 ); | 
 |     add128( z0, z1, 0, more1, &z0, &z1 ); | 
 |     *z3Ptr = z3; | 
 |     *z2Ptr = z2; | 
 |     *z1Ptr = z1; | 
 |     *z0Ptr = z0; | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Returns an approximation to the 64-bit integer quotient obtained by dividing | 
 | `b' into the 128-bit value formed by concatenating `a0' and `a1'.  The | 
 | divisor `b' must be at least 2^63.  If q is the exact quotient truncated | 
 | toward zero, the approximation returned lies between q and q + 2 inclusive. | 
 | If the exact quotient q is larger than 64 bits, the maximum positive 64-bit | 
 | unsigned integer is returned. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | static bits64 estimateDiv128To64( bits64 a0, bits64 a1, bits64 b ) | 
 | { | 
 |     bits64 b0, b1; | 
 |     bits64 rem0, rem1, term0, term1; | 
 |     bits64 z; | 
 |     if ( b <= a0 ) return LIT64( 0xFFFFFFFFFFFFFFFF ); | 
 |     b0 = b>>32;  /* hence b0 is 32 bits wide now */ | 
 |     if ( b0<<32 <= a0 ) { | 
 |         z = LIT64( 0xFFFFFFFF00000000 ); | 
 |     }  else { | 
 |         z = a0; | 
 |         do_div( z, b0 ); | 
 |         z <<= 32; | 
 |     } | 
 |     mul64To128( b, z, &term0, &term1 ); | 
 |     sub128( a0, a1, term0, term1, &rem0, &rem1 ); | 
 |     while ( ( (sbits64) rem0 ) < 0 ) { | 
 |         z -= LIT64( 0x100000000 ); | 
 |         b1 = b<<32; | 
 |         add128( rem0, rem1, b0, b1, &rem0, &rem1 ); | 
 |     } | 
 |     rem0 = ( rem0<<32 ) | ( rem1>>32 ); | 
 |     if ( b0<<32 <= rem0 ) { | 
 |         z |= 0xFFFFFFFF; | 
 |     } else { | 
 |         do_div( rem0, b0 ); | 
 |         z |= rem0; | 
 |     } | 
 |     return z; | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Returns an approximation to the square root of the 32-bit significand given | 
 | by `a'.  Considered as an integer, `a' must be at least 2^31.  If bit 0 of | 
 | `aExp' (the least significant bit) is 1, the integer returned approximates | 
 | 2^31*sqrt(`a'/2^31), where `a' is considered an integer.  If bit 0 of `aExp' | 
 | is 0, the integer returned approximates 2^31*sqrt(`a'/2^30).  In either | 
 | case, the approximation returned lies strictly within +/-2 of the exact | 
 | value. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | static bits32 estimateSqrt32( int16 aExp, bits32 a ) | 
 | { | 
 |     static const bits16 sqrtOddAdjustments[] = { | 
 |         0x0004, 0x0022, 0x005D, 0x00B1, 0x011D, 0x019F, 0x0236, 0x02E0, | 
 |         0x039C, 0x0468, 0x0545, 0x0631, 0x072B, 0x0832, 0x0946, 0x0A67 | 
 |     }; | 
 |     static const bits16 sqrtEvenAdjustments[] = { | 
 |         0x0A2D, 0x08AF, 0x075A, 0x0629, 0x051A, 0x0429, 0x0356, 0x029E, | 
 |         0x0200, 0x0179, 0x0109, 0x00AF, 0x0068, 0x0034, 0x0012, 0x0002 | 
 |     }; | 
 |     int8 index; | 
 |     bits32 z; | 
 |     bits64 A; | 
 |  | 
 |     index = ( a>>27 ) & 15; | 
 |     if ( aExp & 1 ) { | 
 |         z = 0x4000 + ( a>>17 ) - sqrtOddAdjustments[ index ]; | 
 |         z = ( ( a / z )<<14 ) + ( z<<15 ); | 
 |         a >>= 1; | 
 |     } | 
 |     else { | 
 |         z = 0x8000 + ( a>>17 ) - sqrtEvenAdjustments[ index ]; | 
 |         z = a / z + z; | 
 |         z = ( 0x20000 <= z ) ? 0xFFFF8000 : ( z<<15 ); | 
 |         if ( z <= a ) return (bits32) ( ( (sbits32) a )>>1 ); | 
 |     } | 
 |     A = ( (bits64) a )<<31; | 
 |     do_div( A, z ); | 
 |     return ( (bits32) A ) + ( z>>1 ); | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Returns the number of leading 0 bits before the most-significant 1 bit | 
 | of `a'.  If `a' is zero, 32 is returned. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | static int8 countLeadingZeros32( bits32 a ) | 
 | { | 
 |     static const int8 countLeadingZerosHigh[] = { | 
 |         8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, | 
 |         3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, | 
 |         2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, | 
 |         2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, | 
 |         1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | 
 |         1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | 
 |         1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | 
 |         1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, | 
 |         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | 
 |         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | 
 |         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | 
 |         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | 
 |         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | 
 |         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | 
 |         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, | 
 |         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 | 
 |     }; | 
 |     int8 shiftCount; | 
 |  | 
 |     shiftCount = 0; | 
 |     if ( a < 0x10000 ) { | 
 |         shiftCount += 16; | 
 |         a <<= 16; | 
 |     } | 
 |     if ( a < 0x1000000 ) { | 
 |         shiftCount += 8; | 
 |         a <<= 8; | 
 |     } | 
 |     shiftCount += countLeadingZerosHigh[ a>>24 ]; | 
 |     return shiftCount; | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Returns the number of leading 0 bits before the most-significant 1 bit | 
 | of `a'.  If `a' is zero, 64 is returned. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | static int8 countLeadingZeros64( bits64 a ) | 
 | { | 
 |     int8 shiftCount; | 
 |  | 
 |     shiftCount = 0; | 
 |     if ( a < ( (bits64) 1 )<<32 ) { | 
 |         shiftCount += 32; | 
 |     } | 
 |     else { | 
 |         a >>= 32; | 
 |     } | 
 |     shiftCount += countLeadingZeros32( a ); | 
 |     return shiftCount; | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Returns 1 if the 128-bit value formed by concatenating `a0' and `a1' | 
 | is equal to the 128-bit value formed by concatenating `b0' and `b1'. | 
 | Otherwise, returns 0. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE flag eq128( bits64 a0, bits64 a1, bits64 b0, bits64 b1 ) | 
 | { | 
 |  | 
 |     return ( a0 == b0 ) && ( a1 == b1 ); | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Returns 1 if the 128-bit value formed by concatenating `a0' and `a1' is less | 
 | than or equal to the 128-bit value formed by concatenating `b0' and `b1'. | 
 | Otherwise, returns 0. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE flag le128( bits64 a0, bits64 a1, bits64 b0, bits64 b1 ) | 
 | { | 
 |  | 
 |     return ( a0 < b0 ) || ( ( a0 == b0 ) && ( a1 <= b1 ) ); | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Returns 1 if the 128-bit value formed by concatenating `a0' and `a1' is less | 
 | than the 128-bit value formed by concatenating `b0' and `b1'.  Otherwise, | 
 | returns 0. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE flag lt128( bits64 a0, bits64 a1, bits64 b0, bits64 b1 ) | 
 | { | 
 |  | 
 |     return ( a0 < b0 ) || ( ( a0 == b0 ) && ( a1 < b1 ) ); | 
 |  | 
 | } | 
 |  | 
 | /* | 
 | ------------------------------------------------------------------------------- | 
 | Returns 1 if the 128-bit value formed by concatenating `a0' and `a1' is | 
 | not equal to the 128-bit value formed by concatenating `b0' and `b1'. | 
 | Otherwise, returns 0. | 
 | ------------------------------------------------------------------------------- | 
 | */ | 
 | INLINE flag ne128( bits64 a0, bits64 a1, bits64 b0, bits64 b1 ) | 
 | { | 
 |  | 
 |     return ( a0 != b0 ) || ( a1 != b1 ); | 
 |  | 
 | } | 
 |  |