diff options
| author | Thomas Jespersen <laumann.thomas@gmail.com> | 2014-11-25 18:29:18 +0100 |
|---|---|---|
| committer | Thomas Jespersen <laumann.thomas@gmail.com> | 2014-11-25 18:29:18 +0100 |
| commit | a65243782d6f768b5a933063798cda61ce9f6939 (patch) | |
| tree | dbb56b0124e8bc772a8ecc1be90b52441be79c00 /src | |
| parent | 51ecf12487dd87ab5bc2a284a697a85c36143045 (diff) | |
Unfinished division, but growing closer
Diffstat (limited to 'src')
| -rw-r--r-- | src/blk256.c | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/src/blk256.c b/src/blk256.c index da50fc2..9eadfc3 100644 --- a/src/blk256.c +++ b/src/blk256.c @@ -205,6 +205,10 @@ void blk256_sub(blk256_t *rop, blk256_t *op1, blk256_t *op2) if (neg) blk256_set_sign_bit(&r); } + + /** + * Arranged such that abs(opx) >= abs(opy) + */ uint64_t *opx = r.x; uint64_t *opy = sop->x; @@ -227,7 +231,7 @@ void blk256_sub(blk256_t *rop, blk256_t *op1, blk256_t *op2) if (opx[3] < opy[3]) blk256_clear_high_bit(&r); else - r.mx |= (blk256_high_bit(&r) - blk256_high_bit(sop)) & 1; + r.mx |= ((blk256_high_bit(&r) - blk256_high_bit(sop))) & 1; opx[3] -= opy[3]; /* Copy result into rop */ @@ -376,9 +380,11 @@ void blk256_div_blk128(blk256_t *q, blk128_t *r, blk256_t *x, blk128_t *d) double div = blk128_as_double(d); double z, xd; - while (blk256_cmp_blk128(&rr, d) > -1) { + while (blk256_cmp_blk128(&rr, d) > -1 + || blk256_sign_bit(&rr)) { xd = blk256_as_double(&rr); z = xd / div; + printf("r=%lg, d=%lg, z = %lg\n", xd, div, z); double_as_blk256(&t, z); @@ -390,15 +396,10 @@ void blk256_div_blk128(blk256_t *q, blk128_t *r, blk256_t *x, blk128_t *d) */ blk256_mul_blk128(&m, &t, d); - if (blk256_cmp(&m, &rr) > 0) { - blk256_sub(&qq, &qq, &t); - blk256_sub(&m, &m, &rr); - blk256_cp(&rr, &m); - } else { - blk256_add(&qq, &qq, &t); /* Add to divisor found so far */ - blk256_sub(&rr, &rr, &m); - } + blk256_add(&qq, &qq, &t); /* Add to divisor found so far */ + blk256_sub(&rr, &rr, &m); } + printf("\n"); /** * Set quotient |