l64               137 src/dps8/dps8_math128.c     uint64_t l64 = al64 + bl64 + cl64;   // bit 64 a + b + carry in
l64               138 src/dps8/dps8_math128.c     unsigned int c64 = l64 > 1 ? 1 : 0;  // carry out of bit 64
l64               139 src/dps8/dps8_math128.c     l64 = (l64 & 1) << 63;               // put bit 64 in the right place
l64               140 src/dps8/dps8_math128.c     l64 |= l63;                          // put low 63 bits in
l64               142 src/dps8/dps8_math128.c     return construct_128 (h64, l64);