Use copysign instead of ternary for some sin/cos input ranges

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.

diff --git a/ChangeLog b/ChangeLog
index 7f51edd866706ab4e6aa9a70f501729603ecb8a8..9b0bff1b92bdbd5fdf32dfacbe5a2085ea4c0932 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,16 @@
 2016-09-29  Siddhesh Poyarekar  <siddhesh@sourceware.org>
 
+       * 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 (do_cos_slow): use copysign
        instead of ternary condition.
        (do_sin_slow): Likewise.

diff --git a/sysdeps/ieee754/dbl-64/s_sin.c b/sysdeps/ieee754/dbl-64/s_sin.c
index fef6780e1dc8aa097030fc601bad7debd6596ad7..8764c58a9cbcccb41796e79ef75cab0a9ef300e5 100644 (file)
--- 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);
 }