diff options
Diffstat (limited to 'sysdeps/aarch64/fpu/log10f_advsimd.c')
| -rw-r--r-- | sysdeps/aarch64/fpu/log10f_advsimd.c | 29 |
1 files changed, 21 insertions, 8 deletions
diff --git a/sysdeps/aarch64/fpu/log10f_advsimd.c b/sysdeps/aarch64/fpu/log10f_advsimd.c index 82228b5..0d792c3 100644 --- a/sysdeps/aarch64/fpu/log10f_advsimd.c +++ b/sysdeps/aarch64/fpu/log10f_advsimd.c @@ -18,21 +18,25 @@ <https://www.gnu.org/licenses/>. */ #include "v_math.h" -#include "poly_advsimd_f32.h" static const struct data { + float32x4_t c0, c2, c4, c6, inv_ln10, ln2; uint32x4_t off, offset_lower_bound; uint16x8_t special_bound; uint32x4_t mantissa_mask; - float32x4_t poly[8]; - float32x4_t inv_ln10, ln2; + float c1, c3, c5, c7; } data = { /* Use order 9 for log10(1+x), i.e. order 8 for log10(1+x)/x, with x in [-1/3, 1/3] (offset=2/3). Max. relative error: 0x1.068ee468p-25. */ - .poly = { V4 (-0x1.bcb79cp-3f), V4 (0x1.2879c8p-3f), V4 (-0x1.bcd472p-4f), - V4 (0x1.6408f8p-4f), V4 (-0x1.246f8p-4f), V4 (0x1.f0e514p-5f), - V4 (-0x1.0fc92cp-4f), V4 (0x1.f5f76ap-5f) }, + .c0 = V4 (-0x1.bcb79cp-3f), + .c1 = 0x1.2879c8p-3f, + .c2 = V4 (-0x1.bcd472p-4f), + .c3 = 0x1.6408f8p-4f, + .c4 = V4 (-0x1.246f8p-4f), + .c5 = 0x1.f0e514p-5f, + .c6 = V4 (-0x1.0fc92cp-4f), + .c7 = 0x1.f5f76ap-5f, .ln2 = V4 (0x1.62e43p-1f), .inv_ln10 = V4 (0x1.bcb7b2p-2f), /* Lower bound is the smallest positive normal float 0x00800000. For @@ -62,7 +66,7 @@ special_case (float32x4_t y, uint32x4_t u_off, float32x4_t p, float32x4_t r2, float32x4_t VPCS_ATTR NOINLINE V_NAME_F1 (log10) (float32x4_t x) { const struct data *d = ptr_barrier (&data); - + float32x4_t c1357 = vld1q_f32 (&d->c1); /* To avoid having to mov x out of the way, keep u after offset has been applied, and recover x by adding the offset back in the special-case handler. */ @@ -81,7 +85,16 @@ float32x4_t VPCS_ATTR NOINLINE V_NAME_F1 (log10) (float32x4_t x) /* y = log10(1+r) + n * log10(2). */ float32x4_t r2 = vmulq_f32 (r, r); - float32x4_t poly = v_pw_horner_7_f32 (r, r2, d->poly); + + float32x4_t c01 = vfmaq_laneq_f32 (d->c0, r, c1357, 0); + float32x4_t c23 = vfmaq_laneq_f32 (d->c2, r, c1357, 1); + float32x4_t c45 = vfmaq_laneq_f32 (d->c4, r, c1357, 2); + float32x4_t c67 = vfmaq_laneq_f32 (d->c6, r, c1357, 3); + + float32x4_t p47 = vfmaq_f32 (c45, r2, c67); + float32x4_t p27 = vfmaq_f32 (c23, r2, p47); + float32x4_t poly = vfmaq_f32 (c01, r2, p27); + /* y = Log10(2) * n + poly * InvLn(10). */ float32x4_t y = vfmaq_f32 (r, d->ln2, n); y = vmulq_f32 (y, d->inv_ln10); |