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authorH.J. Lu <hjl.tools@gmail.com>2017-12-05 08:32:19 -0800
committerH.J. Lu <hjl.tools@gmail.com>2017-12-05 08:47:27 -0800
commit91c318e7b91467984bf68014ef37539d084a34ab (patch)
tree2ec4488545ff6dfe0495cd33f07e29a38b17acd4 /sysdeps
parentc7e882b70563289ac441f2a3565846221e111d00 (diff)
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s_sinf.c: Replace floor with simple casts
Since s_sinf.c either assigns the return value of floor to integer or
passes double converted from integer to floor, this patch replaces
floor with simple casts.

Also since long == int for 32-bit targets, we can use long instead of
int to avoid 64-bit integer for 64-bit targets.

On Skylake, bench-sinf reports performance improvement:

           Before        After         Improvement
max        130.566       129.564           30%
min        7.704         7.706             0%
mean       21.8188       19.1363           30%

	* sysdeps/ieee754/flt-32/s_sinf.c (reduced): Replace long with
	int.
	(SINF_FUNC): Likewise.  Replace floor with simple casts.
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/ieee754/flt-32/s_sinf.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/sysdeps/ieee754/flt-32/s_sinf.c b/sysdeps/ieee754/flt-32/s_sinf.c
index 40d3d197a8..0b76477d22 100644
--- a/sysdeps/ieee754/flt-32/s_sinf.c
+++ b/sysdeps/ieee754/flt-32/s_sinf.c
@@ -85,8 +85,8 @@ static const int ones[] = { +1, -1 };
    SIGNBIT is used to add the correct sign after the Chebyshev
    polynomial is computed.  */
 static inline float
-reduced (const double theta, const unsigned long int n,
-	 const unsigned long int signbit)
+reduced (const double theta, const unsigned int n,
+	 const unsigned int signbit)
 {
   double sx;
   const double theta2 = theta * theta;
@@ -162,14 +162,14 @@ SINF_FUNC (float x)
     }
   else                          /* |x| >= Pi/4.  */
     {
-      unsigned long int signbit = (x < 0);
+      unsigned int signbit = (x < 0);
       if (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 long int n = (abstheta * inv_PI_4) + 1;
+	  unsigned int n = (abstheta * inv_PI_4) + 1;
 	  theta = abstheta - pio2_table[n / 2];
 	  return reduced (theta, n, signbit);
 	}
@@ -177,8 +177,8 @@ SINF_FUNC (float x)
 	{
 	  if (abstheta < 0x1p+23)     /* |x| < 2^23.  */
 	    {
-	      unsigned long int n = __floor (abstheta * inv_PI_4) + 1.0;
-	      double x = __floor (n / 2.0);
+	      unsigned int n = ((unsigned int) (abstheta * inv_PI_4)) + 1;
+	      double x = n / 2;
 	      theta = x * PI_2_lo + (x * PI_2_hi + abstheta);
 	      /* Argument reduction needed.  */
 	      return reduced (theta, n, signbit);