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[PATCH 4/4] Use copysign instead of ternary for some sin/cos input ranges
- From: Siddhesh Poyarekar <siddhesh at sourceware dot org>
- To: libc-alpha at sourceware dot org
- Date: Tue, 27 Sep 2016 23:19:13 +0530
- Subject: [PATCH 4/4] Use copysign instead of ternary for some sin/cos input ranges
- Authentication-results: sourceware.org; auth=none
- References: <1474998553-2366-1-git-send-email-siddhesh@sourceware.org>
These are remaining cases where we can deduce and conclude that the
sign of the result should be the same as the sign of the input being
checked. For example, for sin(x), the sign of the result is the same
as the result itself for x < pi. Likewise, for sine values where x
after range reduction falls into this range and its sign is preserved.
* sysdeps/ieee754/dbl-64/s_sin.c (do_sincos_1): Use copysign
instead of ternary condition.
(do_sincos_2): Likewise.
(__sin): Likewise.
(__cos): Likewise.
(slow): Likewise.
(sloww): Likewise.
(sloww1): Likewise.
(bsloww): Likewise.
(bsloww1): Likewise.
---
sysdeps/ieee754/dbl-64/s_sin.c | 26 +++++++++++++-------------
1 file changed, 13 insertions(+), 13 deletions(-)
diff --git a/sysdeps/ieee754/dbl-64/s_sin.c b/sysdeps/ieee754/dbl-64/s_sin.c
index e4333a4..40d538d 100644
--- a/sysdeps/ieee754/dbl-64/s_sin.c
+++ b/sysdeps/ieee754/dbl-64/s_sin.c
@@ -344,7 +344,7 @@ do_sincos_1 (double a, double da, double x, int4 n, int4 k)
{
res = do_sin (a, da, &cor);
cor = 1.035 * cor + __copysign (eps, cor);
- retval = ((res == res + cor) ? ((a > 0) ? res : -res)
+ retval = ((res == res + cor) ? __copysign (res, a)
: sloww1 (a, da, x, k));
}
break;
@@ -418,7 +418,7 @@ do_sincos_2 (double a, double da, double x, int4 n, int4 k)
{
res = do_sin (a, da, &cor);
cor = 1.035 * cor + __copysign (eps, cor);
- retval = ((res == res + cor) ? ((a > 0) ? res : -res)
+ retval = ((res == res + cor) ? __copysign (res, a)
: bsloww1 (a, da, x, n));
}
break;
@@ -479,7 +479,7 @@ __sin (double x)
{
res = do_sin (x, 0, &cor);
retval = (res == res + 1.096 * cor) ? res : slow1 (x);
- retval = m > 0 ? retval : -retval;
+ retval = __copysign (retval, x);
} /* else if (k < 0x3feb6000) */
/*----------------------- 0.855469 <|x|<2.426265 ----------------------*/
@@ -489,7 +489,7 @@ __sin (double x)
t = hp0 - fabs (x);
res = do_cos (t, hp1, &cor);
retval = (res == res + 1.020 * cor) ? res : slow2 (x);
- retval = m > 0 ? retval : -retval;
+ retval = __copysign (retval, x);
} /* else if (k < 0x400368fd) */
#ifndef IN_SINCOS
@@ -580,7 +580,7 @@ __cos (double x)
{
res = do_sin (a, da, &cor);
cor = 1.035 * cor + __copysign (1.0e-31, cor);
- retval = ((res == res + cor) ? ((a > 0) ? res : -res)
+ retval = ((res == res + cor) ? __copysign (res, a)
: sloww1 (a, da, x, 1));
}
@@ -634,9 +634,9 @@ slow (double x)
__dubsin (fabs (x), 0, w);
if (w[0] == w[0] + 1.000000001 * w[1])
- return (x > 0) ? w[0] : -w[0];
+ return __copysign (w[0], x);
- return (x > 0) ? __mpsin (x, 0, false) : -__mpsin (-x, 0, false);
+ return __copysign (__mpsin (fabs (x), 0, false), x);
}
/*******************************************************************************/
@@ -717,7 +717,7 @@ sloww (double x, double dx, double orig, int k)
cor = 1.000000001 * w[1] + __copysign (eps, w[1]);
if (w[0] == w[0] + cor)
- return (x > 0) ? w[0] : -w[0];
+ return __copysign (w[0], x);
t = (orig * hpinv + toint);
xn = t - toint;
@@ -743,7 +743,7 @@ sloww (double x, double dx, double orig, int k)
cor = 1.000000001 * w[1] + __copysign (eps, w[1]);
if (w[0] == w[0] + cor)
- return (a > 0) ? w[0] : -w[0];
+ return __copysign (w[0], a);
return k ? __mpcos (orig, 0, true) : __mpsin (orig, 0, true);
}
@@ -764,7 +764,7 @@ sloww1 (double x, double dx, double orig, int k)
res = do_sin_slow (x, dx, 3.1e-30 * fabs (orig), &cor);
if (res == res + cor)
- return (x > 0) ? res : -res;
+ return __copysign (res, x);
dx = (x > 0 ? dx : -dx);
__dubsin (fabs (x), dx, w);
@@ -773,7 +773,7 @@ sloww1 (double x, double dx, double orig, int k)
cor = 1.000000005 * w[1] + __copysign (eps, w[1]);
if (w[0] == w[0] + cor)
- return (x > 0) ? w[0] : -w[0];
+ return __copysign (w[0], x);
return (k == 1) ? __mpcos (orig, 0, true) : __mpsin (orig, 0, true);
}
@@ -833,7 +833,7 @@ bsloww (double x, double dx, double orig, int n)
cor = 1.000000001 * w[1] + __copysign (1.1e-24, w[1]);
if (w[0] == w[0] + cor)
- return (x > 0) ? w[0] : -w[0];
+ return __copysign (w[0], x);
return (n & 1) ? __mpcos (orig, 0, true) : __mpsin (orig, 0, true);
}
@@ -861,7 +861,7 @@ bsloww1 (double x, double dx, double orig, int n)
cor = 1.000000005 * w[1] + __copysign (1.1e-24, w[1]);
if (w[0] == w[0] + cor)
- return (x > 0) ? w[0] : -w[0];
+ return __copysign (w[0], x);
return (n & 1) ? __mpcos (orig, 0, true) : __mpsin (orig, 0, true);
}
--
2.7.4