diff options
Diffstat (limited to 'sysdeps/aarch64/fpu/expm1f_advsimd.c')
| -rw-r--r-- | sysdeps/aarch64/fpu/expm1f_advsimd.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/sysdeps/aarch64/fpu/expm1f_advsimd.c b/sysdeps/aarch64/fpu/expm1f_advsimd.c index 8d4c9a2193..93db200f61 100644 --- a/sysdeps/aarch64/fpu/expm1f_advsimd.c +++ b/sysdeps/aarch64/fpu/expm1f_advsimd.c @@ -23,7 +23,8 @@ static const struct data { float32x4_t poly[5]; - float32x4_t invln2, ln2_lo, ln2_hi, shift; + float32x4_t invln2_and_ln2; + float32x4_t shift; int32x4_t exponent_bias; #if WANT_SIMD_EXCEPT uint32x4_t thresh; @@ -34,9 +35,8 @@ static const struct data /* Generated using fpminimax with degree=5 in [-log(2)/2, log(2)/2]. */ .poly = { V4 (0x1.fffffep-2), V4 (0x1.5554aep-3), V4 (0x1.555736p-5), V4 (0x1.12287cp-7), V4 (0x1.6b55a2p-10) }, - .invln2 = V4 (0x1.715476p+0f), - .ln2_hi = V4 (0x1.62e4p-1f), - .ln2_lo = V4 (0x1.7f7d1cp-20f), + /* Stores constants: invln2, ln2_hi, ln2_lo, 0. */ + .invln2_and_ln2 = { 0x1.715476p+0f, 0x1.62e4p-1f, 0x1.7f7d1cp-20f, 0 }, .shift = V4 (0x1.8p23f), .exponent_bias = V4 (0x3f800000), #if !WANT_SIMD_EXCEPT @@ -80,7 +80,7 @@ float32x4_t VPCS_ATTR NOINLINE V_NAME_F1 (expm1) (float32x4_t x) x = v_zerofy_f32 (x, special); #else /* Handles very large values (+ve and -ve), +/-NaN, +/-Inf. */ - uint32x4_t special = vceqzq_u32 (vcaltq_f32 (x, d->oflow_bound)); + uint32x4_t special = vcagtq_f32 (x, d->oflow_bound); #endif /* Reduce argument to smaller range: @@ -88,10 +88,11 @@ float32x4_t VPCS_ATTR NOINLINE V_NAME_F1 (expm1) (float32x4_t x) and f = x - i * ln2, then f is in [-ln2/2, ln2/2]. exp(x) - 1 = 2^i * (expm1(f) + 1) - 1 where 2^i is exact because i is an integer. */ - float32x4_t j = vsubq_f32 (vfmaq_f32 (d->shift, d->invln2, x), d->shift); + float32x4_t j = vsubq_f32 ( + vfmaq_laneq_f32 (d->shift, x, d->invln2_and_ln2, 0), d->shift); int32x4_t i = vcvtq_s32_f32 (j); - float32x4_t f = vfmsq_f32 (x, j, d->ln2_hi); - f = vfmsq_f32 (f, j, d->ln2_lo); + float32x4_t f = vfmsq_laneq_f32 (x, j, d->invln2_and_ln2, 1); + f = vfmsq_laneq_f32 (f, j, d->invln2_and_ln2, 2); /* Approximate expm1(f) using polynomial. Taylor expansion for expm1(x) has the form: |