diff options
| author | Siddhesh Poyarekar <siddhesh@redhat.com> | 2013-12-20 15:55:34 +0530 |
|---|---|---|
| committer | Siddhesh Poyarekar <siddhesh@redhat.com> | 2013-12-20 15:55:34 +0530 |
| commit | 5ff8d60ef324b9666c92fc342d143e8074043cd1 (patch) | |
| tree | 13e559d95b9a29ccd8a7cf5354e2b1a0295850e7 /sysdeps/ieee754 | |
| parent | 64a17f1adde4715bb6607f64decd73b2df9e6852 (diff) | |
| download | glibc-5ff8d60ef324b9666c92fc342d143e8074043cd1.tar glibc-5ff8d60ef324b9666c92fc342d143e8074043cd1.tar.gz glibc-5ff8d60ef324b9666c92fc342d143e8074043cd1.tar.bz2 glibc-5ff8d60ef324b9666c92fc342d143e8074043cd1.zip | |
Remove some redundant computations in s_sin.c
There are multiple points in the code where the absolute value of a
number is computed multiple times or is computed even though the value
can only be positive. This change removes those redundant
computations. Tested on x86_64 to verify that there were no
regressions in the testsuite.
Diffstat (limited to 'sysdeps/ieee754')
| -rw-r--r-- | sysdeps/ieee754/dbl-64/s_sin.c | 39 |
1 files changed, 15 insertions, 24 deletions
diff --git a/sysdeps/ieee754/dbl-64/s_sin.c b/sysdeps/ieee754/dbl-64/s_sin.c index 9066667040..4e2ac3dbfe 100644 --- a/sysdeps/ieee754/dbl-64/s_sin.c +++ b/sysdeps/ieee754/dbl-64/s_sin.c @@ -290,19 +290,18 @@ __sin (double x) { m = 1; t = a; - db = da; } else { m = 0; t = -a; - db = -da; + da = -da; } u.x = big + t; y = t - (u.x - big); xx = y * y; - s = y + (db + y * xx * (sn3 + xx * sn5)); - c = y * db + xx * (cs2 + xx * (cs4 + xx * cs6)); + s = y + (da + y * xx * (sn3 + xx * sn5)); + c = y * da + xx * (cs2 + xx * (cs4 + xx * cs6)); SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs); cor = (ssn + s * ccs - sn * c) + cs * s; res = sn + cor; @@ -498,19 +497,18 @@ __cos (double x) { m = 1; t = a; - db = da; } else { m = 0; t = -a; - db = -da; + da = -da; } u.x = big + t; y = t - (u.x - big); xx = y * y; - s = y + (db + y * xx * (sn3 + xx * sn5)); - c = y * db + xx * (cs2 + xx * (cs4 + xx * cs6)); + s = y + (da + y * xx * (sn3 + xx * sn5)); + c = y * da + xx * (cs2 + xx * (cs4 + xx * cs6)); SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs); cor = (ssn + s * ccs - sn * c) + cs * s; res = sn + cor; @@ -557,19 +555,18 @@ __cos (double x) { m = 1; t = a; - db = da; } else { m = 0; t = -a; - db = -da; + da = -da; } u.x = big + t; y = t - (u.x - big); xx = y * y; - s = y + (db + y * xx * (sn3 + xx * sn5)); - c = y * db + xx * (cs2 + xx * (cs4 + xx * cs6)); + s = y + (da + y * xx * (sn3 + xx * sn5)); + c = y * da + xx * (cs2 + xx * (cs4 + xx * cs6)); SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs); cor = (ssn + s * ccs - sn * c) + cs * s; res = sn + cor; @@ -899,7 +896,6 @@ sloww1 (double x, double dx, double orig) y = ABS (x); u.x = big + y; y = y - (u.x - big); - dx = (x > 0) ? dx : -dx; xx = y * y; s = y * xx * (sn3 + xx * sn5); c = xx * (cs2 + xx * (cs4 + xx * cs6)); @@ -951,10 +947,8 @@ sloww2 (double x, double dx, double orig, int n) mynumber u; double sn, ssn, cs, ccs, s, c, w[2], y, y1, y2, e1, e2, xx, cor, res; - y = ABS (x); - u.x = big + y; - y = y - (u.x - big); - dx = (x > 0) ? dx : -dx; + u.x = big + x; + y = x - (u.x - big); xx = y * y; s = y * xx * (sn3 + xx * sn5); c = y * dx + xx * (cs2 + xx * (cs4 + xx * cs6)); @@ -979,7 +973,7 @@ sloww2 (double x, double dx, double orig, int n) return (n & 2) ? -res : res; else { - __docos (ABS (x), dx, w); + __docos (x, dx, w); if (w[1] > 0) cor = 1.000000005 * w[1] + 1.1e-30 * ABS (orig); @@ -1254,7 +1248,6 @@ csloww1 (double x, double dx, double orig) y = ABS (x); u.x = big + y; y = y - (u.x - big); - dx = (x > 0) ? dx : -dx; xx = y * y; s = y * xx * (sn3 + xx * sn5); c = xx * (cs2 + xx * (cs4 + xx * cs6)); @@ -1305,10 +1298,8 @@ csloww2 (double x, double dx, double orig, int n) mynumber u; double sn, ssn, cs, ccs, s, c, w[2], y, y1, y2, e1, e2, xx, cor, res; - y = ABS (x); - u.x = big + y; - y = y - (u.x - big); - dx = (x > 0) ? dx : -dx; + u.x = big + x; + y = x - (u.x - big); xx = y * y; s = y * xx * (sn3 + xx * sn5); c = y * dx + xx * (cs2 + xx * (cs4 + xx * cs6)); @@ -1333,7 +1324,7 @@ csloww2 (double x, double dx, double orig, int n) return (n) ? -res : res; else { - __docos (ABS (x), dx, w); + __docos (x, dx, w); if (w[1] > 0) cor = 1.000000005 * w[1] + 1.1e-30 * ABS (orig); else |