diff options
Diffstat (limited to 'soft-fp/op-common.h')
| -rw-r--r-- | soft-fp/op-common.h | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/soft-fp/op-common.h b/soft-fp/op-common.h index 232604e..3abafa1 100644 --- a/soft-fp/op-common.h +++ b/soft-fp/op-common.h @@ -766,3 +766,47 @@ do { \ q = n / d, r = n % d; \ } while (0) + +/* A restoring bit-by-bit division primitive. */ + +#define _FP_DIV_MEAT_N_loop(fs, wc, R, X, Y) \ + do { \ + int count = _FP_WFRACBITS_##fs; \ + _FP_FRAC_DECL_##wc (u); \ + _FP_FRAC_DECL_##wc (v); \ + _FP_FRAC_COPY_##wc (u, X); \ + _FP_FRAC_COPY_##wc (v, Y); \ + _FP_FRAC_SET_##wc (R, _FP_ZEROFRAC_##wc); \ + /* Normalize U and V. */ \ + _FP_FRAC_SLL_##wc (u, _FP_WFRACXBITS_##fs); \ + _FP_FRAC_SLL_##wc (v, _FP_WFRACXBITS_##fs); \ + /* First round. Since the operands are normalized, either the \ + first or second bit will be set in the fraction. Produce a \ + normalized result by checking which and adjusting the loop \ + count and exponent accordingly. */ \ + if (_FP_FRAC_GE_1 (u, v)) \ + { \ + _FP_FRAC_SUB_##wc (u, u, v); \ + _FP_FRAC_LOW_##wc (R) |= 1; \ + count--; \ + } \ + else \ + R##_e--; \ + /* Subsequent rounds. */ \ + do { \ + int msb = (_FP_WS_TYPE) _FP_FRAC_HIGH_##wc (u) < 0; \ + _FP_FRAC_SLL_##wc (u, 1); \ + _FP_FRAC_SLL_##wc (R, 1); \ + if (msb || _FP_FRAC_GE_1 (u, v)) \ + { \ + _FP_FRAC_SUB_##wc (u, u, v); \ + _FP_FRAC_LOW_##wc (R) |= 1; \ + } \ + } while (--count > 0); \ + /* If there's anything left in U, the result is inexact. */ \ + _FP_FRAC_LOW_##wc (R) |= !_FP_FRAC_ZEROP_##wc (u); \ + } while (0) + +#define _FP_DIV_MEAT_1_loop(fs, R, X, Y) _FP_DIV_MEAT_N_loop (fs, 1, R, X, Y) +#define _FP_DIV_MEAT_2_loop(fs, R, X, Y) _FP_DIV_MEAT_N_loop (fs, 2, R, X, Y) +#define _FP_DIV_MEAT_4_loop(fs, R, X, Y) _FP_DIV_MEAT_N_loop (fs, 4, R, X, Y) |