diff options
| -rw-r--r-- | ChangeLog | 14 | ||||
| -rw-r--r-- | math/Makefile | 2 | ||||
| -rw-r--r-- | sysdeps/ia64/fpu/s_sincosf_data.c | 1 | ||||
| -rw-r--r-- | sysdeps/ieee754/flt-32/s_sincosf.c | 196 | ||||
| -rw-r--r-- | sysdeps/ieee754/flt-32/s_sincosf.h | 118 | ||||
| -rw-r--r-- | sysdeps/ieee754/flt-32/s_sincosf_data.c | 74 | ||||
| -rw-r--r-- | sysdeps/m68k/m680x0/fpu/s_sincosf_data.c | 1 | ||||
| -rw-r--r-- | sysdeps/x86_64/fpu/s_sincosf_data.c | 1 |
8 files changed, 274 insertions, 133 deletions
diff --git a/ChangeLog b/ChangeLog index 54c4b5aa85..41da584bc2 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,6 +1,20 @@ 2018-08-10 Wilco Dijkstra <wdijkstr@arm.com> Szabolcs Nagy <szabolcs.nagy@arm.com> + * math/Makefile: Add s_sincosf_data.c. + * sysdeps/ia64/fpu/s_sincosf_data.c: New file. + * sysdeps/ieee754/flt-32/s_sincosf.h (abstop12): Add new function. + (sincosf_poly): Likewise. + (reduce_small): Likewise. + (reduce_large): Likewise. + * sysdeps/ieee754/flt-32/s_sincosf.c (sincosf): Rewrite. + * sysdeps/ieee754/flt-32/s_sincosf_data.c: New file with sincosf data. + * sysdeps/m68k/m680x0/fpu/s_sincosf_data.c: New file. + * sysdeps/x86_64/fpu/s_sincosf_data.c: New file. + +2018-08-10 Wilco Dijkstra <wdijkstr@arm.com> + Szabolcs Nagy <szabolcs.nagy@arm.com> + * sysdeps/aarch64/fpu/math_private.h (roundtoint): Use round. (converttoint): Use lround. * sysdeps/ieee754/flt-32/math_config.h (roundtoint): Declare and diff --git a/math/Makefile b/math/Makefile index d78f40f741..5210430e81 100644 --- a/math/Makefile +++ b/math/Makefile @@ -131,7 +131,7 @@ type-double-routines := branred doasin dosincos mpa mpatan2 \ # float support type-float-suffix := f type-float-routines := k_rem_pio2f math_errf e_exp2f_data e_logf_data \ - e_log2f_data e_powf_log2_data + e_log2f_data e_powf_log2_data s_sincosf_data # _Float128 support type-float128-suffix := f128 diff --git a/sysdeps/ia64/fpu/s_sincosf_data.c b/sysdeps/ia64/fpu/s_sincosf_data.c new file mode 100644 index 0000000000..1cc8931700 --- /dev/null +++ b/sysdeps/ia64/fpu/s_sincosf_data.c @@ -0,0 +1 @@ +/* Not needed. */ diff --git a/sysdeps/ieee754/flt-32/s_sincosf.c b/sysdeps/ieee754/flt-32/s_sincosf.c index d4a5a1b22c..f7e3245097 100644 --- a/sysdeps/ieee754/flt-32/s_sincosf.c +++ b/sysdeps/ieee754/flt-32/s_sincosf.c @@ -1,5 +1,5 @@ /* Compute sine and cosine of argument. - Copyright (C) 2017-2018 Free Software Foundation, Inc. + Copyright (C) 2018 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or @@ -17,9 +17,11 @@ <http://www.gnu.org/licenses/>. */ #include <errno.h> +#include <stdint.h> #include <math.h> -#include <math_private.h> +#include <math-barriers.h> #include <libm-alias-float.h> +#include "math_config.h" #include "s_sincosf.h" #ifndef SINCOSF @@ -28,141 +30,71 @@ # define SINCOSF_FUNC SINCOSF #endif +/* Fast sincosf implementation. Worst-case ULP is 0.5607, maximum relative + error is 0.5303 * 2^-23. A single-step range reduction is used for + small values. Large inputs have their range reduced using fast integer + arithmetic. */ void -SINCOSF_FUNC (float x, float *sinx, float *cosx) +SINCOSF_FUNC (float y, float *sinp, float *cosp) { - double cx; - double theta = x; - double abstheta = fabs (theta); - /* If |x|< Pi/4. */ - if (isless (abstheta, M_PI_4)) + double x = y; + double s; + int n; + const sincos_t *p = &__sincosf_table[0]; + + if (abstop12 (y) < abstop12 (pio4)) + { + double x2 = x * x; + + if (__glibc_unlikely (abstop12 (y) < abstop12 (0x1p-12f))) + { + /* Force underflow for tiny y. */ + if (__glibc_unlikely (abstop12 (y) < abstop12 (0x1p-126f))) + math_force_eval ((float)x2); + *sinp = y; + *cosp = 1.0f; + return; + } + + sincosf_poly (x, x2, p, 0, sinp, cosp); + } + else if (abstop12 (y) < abstop12 (120.0f)) { - if (abstheta >= 0x1p-5) /* |x| >= 2^-5. */ - { - const double theta2 = theta * theta; - /* Chebyshev polynomial of the form for sin and cos. */ - cx = C3 + theta2 * C4; - cx = C2 + theta2 * cx; - cx = C1 + theta2 * cx; - cx = C0 + theta2 * cx; - cx = 1.0 + theta2 * cx; - *cosx = cx; - cx = S3 + theta2 * S4; - cx = S2 + theta2 * cx; - cx = S1 + theta2 * cx; - cx = S0 + theta2 * cx; - cx = theta + theta * theta2 * cx; - *sinx = cx; - } - else if (abstheta >= 0x1p-27) /* |x| >= 2^-27. */ - { - /* A simpler Chebyshev approximation is close enough for this range: - for sin: x+x^3*(SS0+x^2*SS1) - for cos: 1.0+x^2*(CC0+x^3*CC1). */ - const double theta2 = theta * theta; - cx = CC0 + theta * theta2 * CC1; - cx = 1.0 + theta2 * cx; - *cosx = cx; - cx = SS0 + theta2 * SS1; - cx = theta + theta * theta2 * cx; - *sinx = cx; - } - else - { - /* Handle some special cases. */ - if (theta) - *sinx = theta - (theta * SMALL); - else - *sinx = theta; - *cosx = 1.0 - abstheta; - } + x = reduce_fast (x, p, &n); + + /* Setup the signs for sin and cos. */ + s = p->sign[n & 3]; + + if (n & 2) + p = &__sincosf_table[1]; + + sincosf_poly (x * s, x * x, p, n, sinp, cosp); } - else /* |x| >= Pi/4. */ + else if (__glibc_likely (abstop12 (y) < abstop12 (INFINITY))) { - unsigned int signbit = isless (x, 0); - if (isless (abstheta, 9 * M_PI_4)) /* |x| < 9*Pi/4. */ - { - /* There are cases where FE_UPWARD rounding mode can - produce a result of abstheta * inv_PI_4 == 9, - where abstheta < 9pi/4, so the domain for - pio2_table must go to 5 (9 / 2 + 1). */ - unsigned int n = (abstheta * inv_PI_4) + 1; - theta = abstheta - pio2_table[n / 2]; - *sinx = reduced_sin (theta, n, signbit); - *cosx = reduced_cos (theta, n); - } - else if (isless (abstheta, INFINITY)) - { - if (abstheta < 0x1p+23) /* |x| < 2^23. */ - { - unsigned int n = ((unsigned int) (abstheta * inv_PI_4)) + 1; - double x = n / 2; - theta = (abstheta - x * PI_2_hi) - x * PI_2_lo; - /* Argument reduction needed. */ - *sinx = reduced_sin (theta, n, signbit); - *cosx = reduced_cos (theta, n); - } - else /* |x| >= 2^23. */ - { - x = fabsf (x); - int exponent; - GET_FLOAT_WORD (exponent, x); - exponent - = (exponent >> FLOAT_EXPONENT_SHIFT) - FLOAT_EXPONENT_BIAS; - exponent += 3; - exponent /= 28; - double a = invpio4_table[exponent] * x; - double b = invpio4_table[exponent + 1] * x; - double c = invpio4_table[exponent + 2] * x; - double d = invpio4_table[exponent + 3] * x; - uint64_t l = a; - l &= ~0x7; - a -= l; - double e = a + b; - l = e; - e = a - l; - if (l & 1) - { - e -= 1.0; - e += b; - e += c; - e += d; - e *= M_PI_4; - *sinx = reduced_sin (e, l + 1, signbit); - *cosx = reduced_cos (e, l + 1); - } - else - { - e += b; - e += c; - e += d; - if (e <= 1.0) - { - e *= M_PI_4; - *sinx = reduced_sin (e, l + 1, signbit); - *cosx = reduced_cos (e, l + 1); - } - else - { - l++; - e -= 2.0; - e *= M_PI_4; - *sinx = reduced_sin (e, l + 1, signbit); - *cosx = reduced_cos (e, l + 1); - } - } - } - } - else - { - int32_t ix; - /* High word of x. */ - GET_FLOAT_WORD (ix, abstheta); - /* sin/cos(Inf or NaN) is NaN. */ - *sinx = *cosx = x - x; - if (ix == 0x7f800000) - __set_errno (EDOM); - } + uint32_t xi = asuint (y); + int sign = xi >> 31; + + x = reduce_large (xi, &n); + + /* Setup signs for sin and cos - include original sign. */ + s = p->sign[(n + sign) & 3]; + + if ((n + sign) & 2) + p = &__sincosf_table[1]; + + sincosf_poly (x * s, x * x, p, n, sinp, cosp); + } + else + { + /* Return NaN if Inf or NaN for both sin and cos. */ + *sinp = *cosp = y - y; +#if WANT_ERRNO + /* Needed to set errno for +-Inf, the add is a hack to work + around a gcc register allocation issue: just passing y + affects code generation in the fast path (PR86901). */ + __math_invalidf (y + y); +#endif } } diff --git a/sysdeps/ieee754/flt-32/s_sincosf.h b/sysdeps/ieee754/flt-32/s_sincosf.h index 35b5eee536..d3d7b4d6f3 100644 --- a/sysdeps/ieee754/flt-32/s_sincosf.h +++ b/sysdeps/ieee754/flt-32/s_sincosf.h @@ -16,6 +16,10 @@ License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ +#include <stdint.h> +#include <math.h> +#include "math_config.h" + /* Chebyshev constants for cos, range -PI/4 - PI/4. */ static const double C0 = -0x1.ffffffffe98aep-2; static const double C1 = 0x1.55555545c50c7p-5; @@ -153,3 +157,117 @@ reduced_cos (double theta, unsigned int n) } return sign * cx; } + + +/* 2PI * 2^-64. */ +static const double pi63 = 0x1.921FB54442D18p-62; +/* PI / 4. */ +static const double pio4 = 0x1.921FB54442D18p-1; + +/* The constants and polynomials for sine and cosine. */ +typedef struct +{ + double sign[4]; /* Sign of sine in quadrants 0..3. */ + double hpi_inv; /* 2 / PI ( * 2^24 if !TOINT_INTRINSICS). */ + double hpi; /* PI / 2. */ + double c0, c1, c2, c3, c4; /* Cosine polynomial. */ + double s1, s2, s3; /* Sine polynomial. */ +} sincos_t; + +/* Polynomial data (the cosine polynomial is negated in the 2nd entry). */ +extern const sincos_t __sincosf_table[2] attribute_hidden; + +/* Table with 4/PI to 192 bit precision. */ +extern const uint32_t __inv_pio4[] attribute_hidden; + +/* Top 12 bits of the float representation with the sign bit cleared. */ +static inline uint32_t +abstop12 (float x) +{ + return (asuint (x) >> 20) & 0x7ff; +} + +/* Compute the sine and cosine of inputs X and X2 (X squared), using the + polynomial P and store the results in SINP and COSP. N is the quadrant, + if odd the cosine and sine polynomials are swapped. */ +static inline void +sincosf_poly (double x, double x2, const sincos_t *p, int n, float *sinp, + float *cosp) +{ + double x3, x4, x5, x6, s, c, c1, c2, s1; + + x4 = x2 * x2; + x3 = x2 * x; + c2 = p->c3 + x2 * p->c4; + s1 = p->s2 + x2 * p->s3; + + /* Swap sin/cos result based on quadrant. */ + float *tmp = (n & 1 ? cosp : sinp); + cosp = (n & 1 ? sinp : cosp); + sinp = tmp; + + c1 = p->c0 + x2 * p->c1; + x5 = x3 * x2; + x6 = x4 * x2; + + s = x + x3 * p->s1; + c = c1 + x4 * p->c2; + + *sinp = s + x5 * s1; + *cosp = c + x6 * c2; +} + +/* Fast range reduction using single multiply-subtract. Return the modulo of + X as a value between -PI/4 and PI/4 and store the quadrant in NP. + The values for PI/2 and 2/PI are accessed via P. Since PI/2 as a double + is accurate to 55 bits and the worst-case cancellation happens at 6 * PI/4, + the result is accurate for |X| <= 120.0. */ +static inline double +reduce_fast (double x, const sincos_t *p, int *np) +{ + double r; +#if TOINT_INTRINSICS + /* Use fast round and lround instructions when available. */ + r = x * p->hpi_inv; + *np = converttoint (r); + return x - roundtoint (r) * p->hpi; +#else + /* Use scaled float to int conversion with explicit rounding. + hpi_inv is prescaled by 2^24 so the quadrant ends up in bits 24..31. + This avoids inaccuracies introduced by truncating negative values. */ + r = x * p->hpi_inv; + int n = ((int32_t)r + 0x800000) >> 24; + *np = n; + return x - n * p->hpi; +#endif +} + +/* Reduce the range of XI to a multiple of PI/2 using fast integer arithmetic. + XI is a reinterpreted float and must be >= 2.0f (the sign bit is ignored). + Return the modulo between -PI/4 and PI/4 and store the quadrant in NP. + Reduction uses a table of 4/PI with 192 bits of precision. A 32x96->128 bit + multiply computes the exact 2.62-bit fixed-point modulo. Since the result + can have at most 29 leading zeros after the binary point, the double + precision result is accurate to 33 bits. */ +static inline double +reduce_large (uint32_t xi, int *np) +{ + const uint32_t *arr = &__inv_pio4[(xi >> 26) & 15]; + int shift = (xi >> 23) & 7; + uint64_t n, res0, res1, res2; + + xi = (xi & 0xffffff) | 0x800000; + xi <<= shift; + + res0 = xi * arr[0]; + res1 = (uint64_t)xi * arr[4]; + res2 = (uint64_t)xi * arr[8]; + res0 = (res2 >> 32) | (res0 << 32); + res0 += res1; + + n = (res0 + (1ULL << 61)) >> 62; + res0 -= n << 62; + double x = (int64_t)res0; + *np = n; + return x * pi63; +} diff --git a/sysdeps/ieee754/flt-32/s_sincosf_data.c b/sysdeps/ieee754/flt-32/s_sincosf_data.c new file mode 100644 index 0000000000..21fc2b60f9 --- /dev/null +++ b/sysdeps/ieee754/flt-32/s_sincosf_data.c @@ -0,0 +1,74 @@ +/* Compute sine and cosine of argument. + Copyright (C) 2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <stdint.h> +#include <math.h> +#include "math_config.h" +#include "s_sincosf.h" + +/* The constants and polynomials for sine and cosine. The 2nd entry + computes -cos (x) rather than cos (x) to get negation for free. */ +const sincos_t __sincosf_table[2] = +{ + { + { 1.0, -1.0, -1.0, 1.0 }, +#if TOINT_INTRINSICS + 0x1.45F306DC9C883p-1, +#else + 0x1.45F306DC9C883p+23, +#endif + 0x1.921FB54442D18p0, + 0x1p0, + -0x1.ffffffd0c621cp-2, + 0x1.55553e1068f19p-5, + -0x1.6c087e89a359dp-10, + 0x1.99343027bf8c3p-16, + -0x1.555545995a603p-3, + 0x1.1107605230bc4p-7, + -0x1.994eb3774cf24p-13 + }, + { + { 1.0, -1.0, -1.0, 1.0 }, +#if TOINT_INTRINSICS + 0x1.45F306DC9C883p-1, +#else + 0x1.45F306DC9C883p+23, +#endif + 0x1.921FB54442D18p0, + -0x1p0, + 0x1.ffffffd0c621cp-2, + -0x1.55553e1068f19p-5, + 0x1.6c087e89a359dp-10, + -0x1.99343027bf8c3p-16, + -0x1.555545995a603p-3, + 0x1.1107605230bc4p-7, + -0x1.994eb3774cf24p-13 + } +}; + +/* Table with 4/PI to 192 bit precision. To avoid unaligned accesses + only 8 new bits are added per entry, making the table 4 times larger. */ +const uint32_t __inv_pio4[24] = +{ + 0xa2, 0xa2f9, 0xa2f983, 0xa2f9836e, + 0xf9836e4e, 0x836e4e44, 0x6e4e4415, 0x4e441529, + 0x441529fc, 0x1529fc27, 0x29fc2757, 0xfc2757d1, + 0x2757d1f5, 0x57d1f534, 0xd1f534dd, 0xf534ddc0, + 0x34ddc0db, 0xddc0db62, 0xc0db6295, 0xdb629599, + 0x6295993c, 0x95993c43, 0x993c4390, 0x3c439041 +}; diff --git a/sysdeps/m68k/m680x0/fpu/s_sincosf_data.c b/sysdeps/m68k/m680x0/fpu/s_sincosf_data.c new file mode 100644 index 0000000000..1cc8931700 --- /dev/null +++ b/sysdeps/m68k/m680x0/fpu/s_sincosf_data.c @@ -0,0 +1 @@ +/* Not needed. */ diff --git a/sysdeps/x86_64/fpu/s_sincosf_data.c b/sysdeps/x86_64/fpu/s_sincosf_data.c new file mode 100644 index 0000000000..1cc8931700 --- /dev/null +++ b/sysdeps/x86_64/fpu/s_sincosf_data.c @@ -0,0 +1 @@ +/* Not needed. */ |