mirror of git://sourceware.org/git/glibc.git
Consolidate input partitioning into do_cos and do_sin
All calls to do_cos are preceded by code that partitions x into a larger double that gives an offset into the sincos table and a smaller double that is used in a polynomial computation. Consolidate all of them into do_cos and do_sin to reduce code duplication. * sysdeps/ieee754/dbl-64/s_sin.c (do_cos): Accept X and DX as input arguments. Consolidate input partitioning from callers here. (do_cos_slow): Likewise. (do_sin): Likewise. (do_sin_slow): Likewise. (do_sincos_1): Remove the no longer necessary input partitioning. (do_sincos_2): Likewise. (__sin): Likewise. (__cos): Likewise. (slow1): Likewise. (slow2): Likewise. (sloww1): Likewise. (sloww2): Likewise. (bsloww1): Likewise. (bsloww2): Likewise. (cslow2): Likewise.
This commit is contained in:
Siddhesh Poyarekar
parent
9dd87afbf1
commit
758e79ec89
19
ChangeLog
19
ChangeLog
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@ -1,3 +1,22 @@
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2016-09-02 Siddhesh Poyarekar <siddhesh@sourceware.org>
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* sysdeps/ieee754/dbl-64/s_sin.c (do_cos): Accept X and DX as input
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arguments. Consolidate input partitioning from callers here.
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(do_cos_slow): Likewise.
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(do_sin): Likewise.
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(do_sin_slow): Likewise.
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(do_sincos_1): Remove the no longer necessary input partitioning.
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(do_sincos_2): Likewise.
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(__sin): Likewise.
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(__cos): Likewise.
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(slow1): Likewise.
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(slow2): Likewise.
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(sloww1): Likewise.
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(sloww2): Likewise.
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(bsloww1): Likewise.
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(bsloww2): Likewise.
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(cslow2): Likewise.
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2016-09-02 Florian Weimer <fweimer@redhat.com>
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* stdio-common/vfscanf.c (_IO_vfwscanf): Use MB_LEN_MAX instead of
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@ -141,14 +141,21 @@ static double bsloww2 (double x, double dx, double orig, int n);
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int __branred (double x, double *a, double *aa);
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static double cslow2 (double x);
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/* Given a number partitioned into U and X such that U is an index into the
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sin/cos table, this macro computes the cosine of the number by combining
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the sin and cos of X (as computed by a variation of the Taylor series) with
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the values looked up from the sin/cos table to get the result in RES and a
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correction value in COR. */
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/* Given a number partitioned into X and DX, this function computes the cosine
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of the number by combining the sin and cos of X (as computed by a variation
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of the Taylor series) with the values looked up from the sin/cos table to
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get the result in RES and a correction value in COR. */
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static double
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do_cos (mynumber u, double x, double *corp)
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do_cos (double x, double dx, double *corp)
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{
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mynumber u;
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if (x < 0)
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dx = -dx;
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u.x = big + fabs (x);
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x = fabs (x) - (u.x - big) + dx;
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double xx, s, sn, ssn, c, cs, ccs, res, cor;
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xx = x * x;
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s = x + x * xx * (sn3 + xx * sn5);
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@ -161,11 +168,19 @@ do_cos (mynumber u, double x, double *corp)
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return res;
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}
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/* A more precise variant of DO_COS where the number is partitioned into U, X
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and DX. EPS is the adjustment to the correction COR. */
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/* A more precise variant of DO_COS. EPS is the adjustment to the correction
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COR. */
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static double
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do_cos_slow (mynumber u, double x, double dx, double eps, double *corp)
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do_cos_slow (double x, double dx, double eps, double *corp)
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{
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mynumber u;
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if (x <= 0)
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dx = -dx;
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u.x = big + fabs (x);
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x = fabs (x) - (u.x - big);
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double xx, y, x1, x2, e1, e2, res, cor;
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double s, sn, ssn, c, cs, ccs;
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xx = x * x;
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@ -186,14 +201,20 @@ do_cos_slow (mynumber u, double x, double dx, double eps, double *corp)
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return res;
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}
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/* Given a number partitioned into U and X and DX such that U is an index into
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the sin/cos table, this macro computes the sine of the number by combining
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the sin and cos of X (as computed by a variation of the Taylor series) with
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the values looked up from the sin/cos table to get the result in RES and a
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correction value in COR. */
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/* Given a number partitioned into X and DX, this function computes the sine of
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the number by combining the sin and cos of X (as computed by a variation of
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the Taylor series) with the values looked up from the sin/cos table to get
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the result in RES and a correction value in COR. */
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static double
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do_sin (mynumber u, double x, double dx, double *corp)
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do_sin (double x, double dx, double *corp)
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{
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mynumber u;
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if (x <= 0)
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dx = -dx;
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u.x = big + fabs (x);
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x = fabs (x) - (u.x - big);
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double xx, s, sn, ssn, c, cs, ccs, cor, res;
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xx = x * x;
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s = x + (dx + x * xx * (sn3 + xx * sn5));
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@ -206,11 +227,18 @@ do_sin (mynumber u, double x, double dx, double *corp)
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return res;
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}
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/* A more precise variant of res = do_sin where the number is partitioned into U, X
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and DX. EPS is the adjustment to the correction COR. */
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/* A more precise variant of DO_SIN. EPS is the adjustment to the correction
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COR. */
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static double
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do_sin_slow (mynumber u, double x, double dx, double eps, double *corp)
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do_sin_slow (double x, double dx, double eps, double *corp)
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{
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mynumber u;
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if (x <= 0)
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dx = -dx;
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u.x = big + fabs (x);
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x = fabs (x) - (u.x - big);
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double xx, y, x1, x2, c1, c2, res, cor;
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double s, sn, ssn, c, cs, ccs;
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xx = x * x;
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@ -289,8 +317,7 @@ static double
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__always_inline
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do_sincos_1 (double a, double da, double x, int4 n, int4 k)
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{
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double xx, retval, res, cor, y;
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mynumber u;
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double xx, retval, res, cor;
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double eps = fabs (x) * 1.2e-30;
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int k1 = (n + k) & 3;
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@ -311,10 +338,7 @@ do_sincos_1 (double a, double da, double x, int4 n, int4 k)
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}
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else
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{
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double db = (a > 0 ? da : -da);
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u.x = big + fabs (a);
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y = fabs (a) - (u.x - big);
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res = do_sin (u, y, db, &cor);
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res = do_sin (a, da, &cor);
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cor = (cor > 0) ? 1.035 * cor + eps : 1.035 * cor - eps;
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retval = ((res == res + cor) ? ((a > 0) ? res : -res)
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: sloww1 (a, da, x, k));
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@ -323,16 +347,11 @@ do_sincos_1 (double a, double da, double x, int4 n, int4 k)
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case 1:
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case 3:
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{
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double db = (a > 0 ? da : -da);
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u.x = big + fabs (a);
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y = fabs (a) - (u.x - big) + db;
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res = do_cos (u, y, &cor);
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cor = (cor > 0) ? 1.025 * cor + eps : 1.025 * cor - eps;
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retval = ((res == res + cor) ? ((k1 & 2) ? -res : res)
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: sloww2 (a, da, x, n));
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break;
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}
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res = do_cos (a, da, &cor);
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cor = (cor > 0) ? 1.025 * cor + eps : 1.025 * cor - eps;
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retval = ((res == res + cor) ? ((k1 & 2) ? -res : res)
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: sloww2 (a, da, x, n));
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break;
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}
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return retval;
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@ -371,7 +390,6 @@ __always_inline
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do_sincos_2 (double a, double da, double x, int4 n, int4 k)
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{
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double res, retval, cor, xx;
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mynumber u;
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double eps = 1.0e-24;
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@ -394,10 +412,7 @@ do_sincos_2 (double a, double da, double x, int4 n, int4 k)
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}
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else
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{
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double db = (a > 0 ? da : -da);
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u.x = big + fabs (a);
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double y = fabs (a) - (u.x - big);
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res = do_sin (u, y, db, &cor);
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res = do_sin (a, da, &cor);
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cor = (cor > 0) ? 1.035 * cor + eps : 1.035 * cor - eps;
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retval = ((res == res + cor) ? ((a > 0) ? res : -res)
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: bsloww1 (a, da, x, n));
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@ -406,16 +421,11 @@ do_sincos_2 (double a, double da, double x, int4 n, int4 k)
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case 1:
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case 3:
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{
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double db = (a > 0 ? da : -da);
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u.x = big + fabs (a);
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double y = fabs (a) - (u.x - big) + db;
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res = do_cos (u, y, &cor);
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cor = (cor > 0) ? 1.025 * cor + eps : 1.025 * cor - eps;
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retval = ((res == res + cor) ? ((n & 2) ? -res : res)
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: bsloww2 (a, da, x, n));
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break;
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}
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res = do_cos (a, da, &cor);
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cor = (cor > 0) ? 1.025 * cor + eps : 1.025 * cor - eps;
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retval = ((res == res + cor) ? ((n & 2) ? -res : res)
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: bsloww2 (a, da, x, n));
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break;
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}
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return retval;
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@ -487,11 +497,7 @@ __sin (double x)
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{
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t = hp0 - fabs (x);
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u.x = big + fabs (t);
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y = fabs (t) - (u.x - big);
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y = ((t >= 0) ? hp1 : -hp1) + y;
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res = do_cos (u, y, &cor);
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res = do_cos (t, hp1, &cor);
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retval = (res == res + 1.020 * cor) ? ((m > 0) ? res : -res) : slow2 (x);
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} /* else if (k < 0x400368fd) */
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@ -563,10 +569,7 @@ __cos (double x)
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else if (k < 0x3feb6000)
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{ /* 2^-27 < |x| < 0.855469 */
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y = fabs (x);
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u.x = big + y;
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y = y - (u.x - big);
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res = do_cos (u, y, &cor);
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res = do_cos (x, 0, &cor);
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retval = (res == res + 1.020 * cor) ? res : cslow2 (x);
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} /* else if (k < 0x3feb6000) */
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@ -584,10 +587,7 @@ __cos (double x)
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}
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else
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{
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double db = (a > 0 ? da : -da);
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u.x = big + fabs (a);
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y = fabs (a) - (u.x - big);
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res = do_sin (u, y, db, &cor);
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res = do_sin (a, da, &cor);
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cor = (cor > 0) ? 1.035 * cor + 1.0e-31 : 1.035 * cor - 1.0e-31;
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retval = ((res == res + cor) ? ((a > 0) ? res : -res)
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: sloww1 (a, da, x, 1));
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@ -657,12 +657,9 @@ static double
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SECTION
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slow1 (double x)
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{
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mynumber u;
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double w[2], y, cor, res;
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y = fabs (x);
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u.x = big + y;
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y = y - (u.x - big);
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res = do_sin_slow (u, y, 0, 0, &cor);
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double w[2], cor, res;
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res = do_sin_slow (x, 0, 0, &cor);
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if (res == res + cor)
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return (x > 0) ? res : -res;
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@ -681,15 +678,10 @@ static double
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SECTION
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slow2 (double x)
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{
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mynumber u;
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double w[2], y, y1, y2, cor, res, del;
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double w[2], y, y1, y2, cor, res;
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double t = hp0 - fabs (x);
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u.x = big + fabs (t);
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y = fabs (t) - (u.x - big);
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del = (t >= 0) ? hp1 : -hp1;
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res = do_cos_slow (u, y, del, 0, &cor);
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res = do_cos_slow (t, hp1, 0, &cor);
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if (res == res + cor)
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return (x > 0) ? res : -res;
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@ -776,17 +768,14 @@ static double
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SECTION
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sloww1 (double x, double dx, double orig, int k)
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{
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mynumber u;
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double w[2], y, cor, res;
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double w[2], cor, res;
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u.x = big + fabs (x);
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y = fabs (x) - (u.x - big);
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dx = (x > 0 ? dx : -dx);
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res = do_sin_slow (u, y, dx, 3.1e-30 * fabs (orig), &cor);
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res = do_sin_slow (x, dx, 3.1e-30 * fabs (orig), &cor);
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if (res == res + cor)
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return (x > 0) ? res : -res;
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dx = (x > 0 ? dx : -dx);
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__dubsin (fabs (x), dx, w);
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double eps = 1.1e-30 * fabs (orig);
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@ -809,17 +798,14 @@ static double
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SECTION
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sloww2 (double x, double dx, double orig, int n)
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{
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mynumber u;
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double w[2], y, cor, res;
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double w[2], cor, res;
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u.x = big + fabs (x);
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y = fabs (x) - (u.x - big);
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dx = (x > 0 ? dx : -dx);
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res = do_cos_slow (u, y, dx, 3.1e-30 * fabs (orig), &cor);
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res = do_cos_slow (x, dx, 3.1e-30 * fabs (orig), &cor);
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if (res == res + cor)
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return (n & 2) ? -res : res;
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dx = x > 0 ? dx : -dx;
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__docos (fabs (x), dx, w);
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double eps = 1.1e-30 * fabs (orig);
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@ -872,17 +858,13 @@ static double
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SECTION
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bsloww1 (double x, double dx, double orig, int n)
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{
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mynumber u;
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double w[2], y, cor, res;
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double w[2], cor, res;
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y = fabs (x);
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u.x = big + y;
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y = y - (u.x - big);
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dx = (x > 0) ? dx : -dx;
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res = do_sin_slow (u, y, dx, 1.1e-24, &cor);
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res = do_sin_slow (x, dx, 1.1e-24, &cor);
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if (res == res + cor)
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return (x > 0) ? res : -res;
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dx = (x > 0) ? dx : -dx;
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__dubsin (fabs (x), dx, w);
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cor = 1.000000005 * w[1] + ((w[1] > 0) ? 1.1e-24 : -1.1e-24);
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@ -904,17 +886,13 @@ static double
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SECTION
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bsloww2 (double x, double dx, double orig, int n)
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{
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mynumber u;
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double w[2], y, cor, res;
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double w[2], cor, res;
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y = fabs (x);
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u.x = big + y;
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y = y - (u.x - big);
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dx = (x > 0) ? dx : -dx;
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res = do_cos_slow (u, y, dx, 1.1e-24, &cor);
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res = do_cos_slow (x, dx, 1.1e-24, &cor);
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if (res == res + cor)
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return (n & 2) ? -res : res;
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dx = (x > 0) ? dx : -dx;
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__docos (fabs (x), dx, w);
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cor = 1.000000005 * w[1] + ((w[1] > 0) ? 1.1e-24 : -1.1e-24);
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@ -934,18 +912,13 @@ static double
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SECTION
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cslow2 (double x)
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{
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mynumber u;
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double w[2], y, cor, res;
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double w[2], cor, res;
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y = fabs (x);
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u.x = big + y;
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y = y - (u.x - big);
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res = do_cos_slow (u, y, 0, 0, &cor);
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res = do_cos_slow (x, 0, 0, &cor);
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if (res == res + cor)
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return res;
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y = fabs (x);
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__docos (y, 0, w);
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__docos (fabs (x), 0, w);
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if (w[0] == w[0] + 1.000000005 * w[1])
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return w[0];
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