softfloat/s_mul64To128.c

   1
   2 #include <stdint.h>
   3 #include "platform.h"
   4 #include "primitives.h"
   5
   6 struct uint128 softfloat_mul64To128( uint64_t a, uint64_t b )
   7 {
   8     uint32_t a32, a0, b32, b0;
   9     struct uint128 z;
  10     uint64_t mid1, mid2, mid;
  11
  12     a32 = a>>32;
  13     a0 = a;
  14     b32 = b>>32;
  15     b0 = b;
  16     z.v0 = (uint64_t) a0 * b0;
  17     mid1 = (uint64_t) a32 * b0;
  18     mid2 = (uint64_t) a0 * b32;
  19     z.v64 = (uint64_t) a32 * b32;
  20     mid = mid1 + mid2;
  21     z.v64 += ( (uint64_t) ( mid < mid1 ) )<<32 | mid>>32;
  22     mid <<= 32;
  23     z.v0 += mid;
  24     z.v64 += ( z.v0 < mid );
  25     return z;
  26
  27 }
  28