Consolidate code to compute sin and cos from lookup tables

This patch consolidates the multiple copies of code that looks up sin
and cos of a number from the lookup table and computes the final
value, into static functions.  This does not have a noticeable
performance impact since the functions are inlined by gcc.

There is further scope for consolidation in the functions but they
cause a more noticable impact on performance (>5%) due to which I have
held back on them.

1 files changed, 129 insertions, 232 deletions

diff --git a/sysdeps/ieee754/dbl-64/s_sin.c b/sysdeps/ieee754/dbl-64/s_sin.c
index 0033f94..bd2346c 100644
--- a/sysdeps/ieee754/dbl-64/s_sin.c
+++ b/sysdeps/ieee754/dbl-64/s_sin.c
@@ -145,6 +145,102 @@ static double csloww (double x, double dx, double orig);
 static double csloww1 (double x, double dx, double orig, int m);
 static double csloww2 (double x, double dx, double orig, int n);
 
+/* Given a number partitioned into U and X such that U is an index into the
+   sin/cos table, this macro computes the cosine of the number by combining
+   the sin and cos of X (as computed by a variation of the Taylor series) with
+   the values looked up from the sin/cos table to get the result in RES and a
+   correction value in COR.  */
+static double
+do_cos (mynumber u, double x, double *corp)
+{
+  double xx, s, sn, ssn, c, cs, ccs, res, cor;
+  xx = x * x;
+  s = x + x * xx * (sn3 + xx * sn5);
+  c = xx * (cs2 + xx * (cs4 + xx * cs6));
+  SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
+  cor = (ccs - s * ssn - cs * c) - sn * s;
+  res = cs + cor;
+  cor = (cs - res) + cor;
+  *corp = cor;
+  return res;
+}
+
+/* A more precise variant of DO_COS where the number is partitioned into U, X
+   and DX.  EPS is the adjustment to the correction COR.  */
+static double
+do_cos_slow (mynumber u, double x, double dx, double eps, double *corp)
+{
+  double xx, y, x1, x2, e1, e2, res, cor;
+  double s, sn, ssn, c, cs, ccs;
+  xx = x * x;
+  s = x * xx * (sn3 + xx * sn5);
+  c = x * dx + xx * (cs2 + xx * (cs4 + xx * cs6));
+  SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
+  x1 = (x + t22) - t22;
+  x2 = (x - x1) + dx;
+  e1 = (sn + t22) - t22;
+  e2 = (sn - e1) + ssn;
+  cor = (ccs - cs * c - e1 * x2 - e2 * x) - sn * s;
+  y = cs - e1 * x1;
+  cor = cor + ((cs - y) - e1 * x1);
+  res = y + cor;
+  cor = (y - res) + cor;
+  if (cor > 0)
+    cor = 1.0005 * cor + eps;
+  else
+    cor = 1.0005 * cor - eps;
+  *corp = cor;
+  return res;
+}
+
+/* Given a number partitioned into U and X and DX such that U is an index into
+   the sin/cos table, this macro computes the sine of the number by combining
+   the sin and cos of X (as computed by a variation of the Taylor series) with
+   the values looked up from the sin/cos table to get the result in RES and a
+   correction value in COR.  */
+static double
+do_sin (mynumber u, double x, double dx, double *corp)
+{
+  double xx, s, sn, ssn, c, cs, ccs, cor, res;
+  xx = x * x;
+  s = x + (dx + x * xx * (sn3 + xx * sn5));
+  c = x * dx + 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;
+  cor = (sn - res) + cor;
+  *corp = cor;
+  return res;
+}
+
+/* A more precise variant of res = do_sin where the number is partitioned into U, X
+   and DX.  EPS is the adjustment to the correction COR.  */
+static double
+do_sin_slow (mynumber u, double x, double dx, double eps, double *corp)
+{
+  double xx, y, x1, x2, c1, c2, res, cor;
+  double s, sn, ssn, c, cs, ccs;
+  xx = x * x;
+  s = x * xx * (sn3 + xx * sn5);
+  c = xx * (cs2 + xx * (cs4 + xx * cs6));
+  SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
+  x1 = (x + t22) - t22;
+  x2 = (x - x1) + dx;
+  c1 = (cs + t22) - t22;
+  c2 = (cs - c1) + ccs;
+  cor = (ssn + s * ccs + cs * s + c2 * x + c1 * x2 - sn * x * dx) - sn * c;
+  y = sn + c1 * x1;
+  cor = cor + ((sn - y) + c1 * x1);
+  res = y + cor;
+  cor = (y - res) + cor;
+  if (cor > 0)
+    cor = 1.0005 * cor + eps;
+  else
+    cor = 1.0005 * cor - eps;
+  *corp = cor;
+  return res;
+}
+
 /* Reduce range of X and compute sin of a + da.  K is the amount by which to
    rotate the quadrants.  This allows us to use the same routine to compute cos
    by simply rotating the quadrants by 1.  */
@@ -244,13 +340,7 @@ __sin (double x)
 	  u.x = big - y;
 	  y = (-hp1) - (y + (u.x - big));
 	}
-      xx = y * y;
-      s = y + y * xx * (sn3 + xx * sn5);
-      c = xx * (cs2 + xx * (cs4 + xx * cs6));
-      SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
-      cor = (ccs - s * ssn - cs * c) - sn * s;
-      res = cs + cor;
-      cor = (cs - res) + cor;
+      res = do_cos (u, y, &cor);
       retval = (res == res + 1.020 * cor) ? ((m > 0) ? res : -res) : slow2 (x);
     }				/*   else  if (k < 0x400368fd)    */
 
@@ -296,13 +386,7 @@ __sin (double x)
 		}
 	      u.x = big + a;
 	      y = a - (u.x - big);
-	      xx = y * y;
-	      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;
-	      cor = (sn - res) + cor;
+	      res = do_sin (u, y, da, &cor);
 	      cor = (cor > 0) ? 1.035 * cor + eps : 1.035 * cor - eps;
 	      retval = ((res == res + cor) ? ((m) ? res : -res)
 			: sloww1 (a, da, x, m));
@@ -318,13 +402,7 @@ __sin (double x)
 	    }
 	  u.x = big + a;
 	  y = a - (u.x - big) + da;
-	  xx = y * y;
-	  SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
-	  s = y + y * xx * (sn3 + xx * sn5);
-	  c = xx * (cs2 + xx * (cs4 + xx * cs6));
-	  cor = (ccs - s * ssn - cs * c) - sn * s;
-	  res = cs + cor;
-	  cor = (cs - res) + cor;
+	  res = do_cos (u, y, &cor);
 	  cor = (cor > 0) ? 1.025 * cor + eps : 1.025 * cor - eps;
 	  retval = ((res == res + cor) ? ((n & 2) ? -res : res)
 		    : sloww2 (a, da, x, n));
@@ -382,13 +460,7 @@ __sin (double x)
 		}
 	      u.x = big + a;
 	      y = a - (u.x - big);
-	      xx = y * y;
-	      s = y + (db + y * xx * (sn3 + xx * sn5));
-	      c = y * db + 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;
-	      cor = (sn - res) + cor;
+	      res = do_sin (u, y, db, &cor);
 	      cor = (cor > 0) ? 1.035 * cor + eps : 1.035 * cor - eps;
 	      retval = ((res == res + cor) ? ((m) ? res : -res)
 			: bsloww1 (a, da, x, n));
@@ -404,13 +476,7 @@ __sin (double x)
 	    }
 	  u.x = big + a;
 	  y = a - (u.x - big) + da;
-	  xx = y * y;
-	  SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
-	  s = y + y * xx * (sn3 + xx * sn5);
-	  c = xx * (cs2 + xx * (cs4 + xx * cs6));
-	  cor = (ccs - s * ssn - cs * c) - sn * s;
-	  res = cs + cor;
-	  cor = (cs - res) + cor;
+	  res = do_cos (u, y, &cor);
 	  cor = (cor > 0) ? 1.025 * cor + eps : 1.025 * cor - eps;
 	  retval = ((res == res + cor) ? ((n & 2) ? -res : res)
 		    : bsloww2 (a, da, x, n));
@@ -443,7 +509,7 @@ double
 SECTION
 __cos (double x)
 {
-  double y, xx, res, t, cor, s, c, sn, ssn, cs, ccs, xn, a, da, db, eps, xn1,
+  double y, xx, res, t, cor, xn, a, da, db, eps, xn1,
     xn2;
   mynumber u, v;
   int4 k, m, n;
@@ -465,13 +531,7 @@ __cos (double x)
       y = ABS (x);
       u.x = big + y;
       y = y - (u.x - big);
-      xx = y * y;
-      s = y + y * xx * (sn3 + xx * sn5);
-      c = xx * (cs2 + xx * (cs4 + xx * cs6));
-      SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
-      cor = (ccs - s * ssn - cs * c) - sn * s;
-      res = cs + cor;
-      cor = (cs - res) + cor;
+      res = do_cos (u, y, &cor);
       retval = (res == res + 1.020 * cor) ? res : cslow2 (x);
     }				/*   else  if (k < 0x3feb6000)    */
 
@@ -501,13 +561,7 @@ __cos (double x)
 	    }
 	  u.x = big + a;
 	  y = a - (u.x - big);
-	  xx = y * y;
-	  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;
-	  cor = (sn - res) + cor;
+	  res = do_sin (u, y, da, &cor);
 	  cor = (cor > 0) ? 1.035 * cor + 1.0e-31 : 1.035 * cor - 1.0e-31;
 	  retval = ((res == res + cor) ? ((m) ? res : -res)
 		    : csloww1 (a, da, x, m));
@@ -558,13 +612,7 @@ __cos (double x)
 		}
 	      u.x = big + a;
 	      y = a - (u.x - big);
-	      xx = y * y;
-	      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;
-	      cor = (sn - res) + cor;
+	      res = do_sin (u, y, da, &cor);
 	      cor = (cor > 0) ? 1.035 * cor + eps : 1.035 * cor - eps;
 	      retval = ((res == res + cor) ? ((m) ? res : -res)
 			: csloww1 (a, da, x, m));
@@ -580,13 +628,7 @@ __cos (double x)
 	    }
 	  u.x = big + a;
 	  y = a - (u.x - big) + da;
-	  xx = y * y;
-	  SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
-	  s = y + y * xx * (sn3 + xx * sn5);
-	  c = xx * (cs2 + xx * (cs4 + xx * cs6));
-	  cor = (ccs - s * ssn - cs * c) - sn * s;
-	  res = cs + cor;
-	  cor = (cs - res) + cor;
+	  res = do_cos (u, y, &cor);
 	  cor = (cor > 0) ? 1.025 * cor + eps : 1.025 * cor - eps;
 	  retval = ((res == res + cor) ? ((n) ? -res : res)
 		    : csloww2 (a, da, x, n));
@@ -642,13 +684,7 @@ __cos (double x)
 		}
 	      u.x = big + a;
 	      y = a - (u.x - big);
-	      xx = y * y;
-	      s = y + (db + y * xx * (sn3 + xx * sn5));
-	      c = y * db + 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;
-	      cor = (sn - res) + cor;
+	      res = do_sin (u, y, db, &cor);
 	      cor = (cor > 0) ? 1.035 * cor + eps : 1.035 * cor - eps;
 	      retval = ((res == res + cor) ? ((m) ? res : -res)
 			: bsloww1 (a, da, x, n));
@@ -664,13 +700,7 @@ __cos (double x)
 	    }
 	  u.x = big + a;
 	  y = a - (u.x - big) + da;
-	  xx = y * y;
-	  SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
-	  s = y + y * xx * (sn3 + xx * sn5);
-	  c = xx * (cs2 + xx * (cs4 + xx * cs6));
-	  cor = (ccs - s * ssn - cs * c) - sn * s;
-	  res = cs + cor;
-	  cor = (cs - res) + cor;
+	  res = do_cos (u, y, &cor);
 	  cor = (cor > 0) ? 1.025 * cor + eps : 1.025 * cor - eps;
 	  retval = ((res == res + cor) ? ((n) ? -res : res)
 		    : bsloww2 (a, da, x, n));
@@ -725,24 +755,12 @@ SECTION
 slow1 (double x)
 {
   mynumber u;
-  double sn, ssn, cs, ccs, s, c, w[2], y, y1, y2, c1, c2, xx, cor, res;
+  double w[2], y, cor, res;
   y = ABS (x);
   u.x = big + y;
   y = y - (u.x - big);
-  xx = y * y;
-  s = y * xx * (sn3 + xx * sn5);
-  c = xx * (cs2 + xx * (cs4 + xx * cs6));
-  SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
-  y1 = (y + t22) - t22;
-  y2 = y - y1;
-  c1 = (cs + t22) - t22;
-  c2 = (cs - c1) + ccs;
-  cor = (ssn + s * ccs + cs * s + c2 * y + c1 * y2) - sn * c;
-  y = sn + c1 * y1;
-  cor = cor + ((sn - y) + c1 * y1);
-  res = y + cor;
-  cor = (y - res) + cor;
-  if (res == res + 1.0005 * cor)
+  res = do_sin_slow (u, y, 0, 0, &cor);
+  if (res == res + cor)
     return (x > 0) ? res : -res;
   else
     {
@@ -763,7 +781,7 @@ SECTION
 slow2 (double x)
 {
   mynumber u;
-  double sn, ssn, cs, ccs, s, c, w[2], y, y1, y2, e1, e2, xx, cor, res, del;
+  double w[2], y, y1, y2, cor, res, del;
 
   y = ABS (x);
   y = hp0 - y;
@@ -779,20 +797,8 @@ slow2 (double x)
       y = -(y + (u.x - big));
       del = -hp1;
     }
-  xx = y * y;
-  s = y * xx * (sn3 + xx * sn5);
-  c = y * del + xx * (cs2 + xx * (cs4 + xx * cs6));
-  SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
-  y1 = (y + t22) - t22;
-  y2 = (y - y1) + del;
-  e1 = (sn + t22) - t22;
-  e2 = (sn - e1) + ssn;
-  cor = (ccs - cs * c - e1 * y2 - e2 * y) - sn * s;
-  y = cs - e1 * y1;
-  cor = cor + ((cs - y) - e1 * y1);
-  res = y + cor;
-  cor = (y - res) + cor;
-  if (res == res + 1.0005 * cor)
+  res = do_cos_slow (u, y, del, 0, &cor);
+  if (res == res + cor)
     return (x > 0) ? res : -res;
   else
     {
@@ -884,28 +890,11 @@ SECTION
 sloww1 (double x, double dx, double orig, int m)
 {
   mynumber u;
-  double sn, ssn, cs, ccs, s, c, w[2], y, y1, y2, c1, c2, xx, cor, res;
+  double w[2], y, cor, res;
 
   u.x = big + x;
   y = x - (u.x - big);
-  xx = y * y;
-  s = y * xx * (sn3 + xx * sn5);
-  c = xx * (cs2 + xx * (cs4 + xx * cs6));
-  SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
-  y1 = (y + t22) - t22;
-  y2 = (y - y1) + dx;
-  c1 = (cs + t22) - t22;
-  c2 = (cs - c1) + ccs;
-  cor = (ssn + s * ccs + cs * s + c2 * y + c1 * y2 - sn * y * dx) - sn * c;
-  y = sn + c1 * y1;
-  cor = cor + ((sn - y) + c1 * y1);
-  res = y + cor;
-  cor = (y - res) + cor;
-
-  if (cor > 0)
-    cor = 1.0005 * cor + 3.1e-30 * ABS (orig);
-  else
-    cor = 1.0005 * cor - 3.1e-30 * ABS (orig);
+  res = do_sin_slow (u, y, dx, 3.1e-30 * ABS (orig), &cor);
 
   if (res == res + cor)
     return (m > 0) ? res : -res;
@@ -937,29 +926,11 @@ SECTION
 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;
+  double w[2], y, cor, res;
 
   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));
-  SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
-
-  y1 = (y + t22) - t22;
-  y2 = (y - y1) + dx;
-  e1 = (sn + t22) - t22;
-  e2 = (sn - e1) + ssn;
-  cor = (ccs - cs * c - e1 * y2 - e2 * y) - sn * s;
-  y = cs - e1 * y1;
-  cor = cor + ((cs - y) - e1 * y1);
-  res = y + cor;
-  cor = (y - res) + cor;
-
-  if (cor > 0)
-    cor = 1.0005 * cor + 3.1e-30 * ABS (orig);
-  else
-    cor = 1.0005 * cor - 3.1e-30 * ABS (orig);
+  res = do_cos_slow (u, y, dx, 3.1e-30 * ABS (orig), &cor);
 
   if (res == res + cor)
     return (n & 2) ? -res : res;
@@ -1023,26 +994,13 @@ SECTION
 bsloww1 (double x, double dx, double orig, int n)
 {
   mynumber u;
-  double sn, ssn, cs, ccs, s, c, w[2], y, y1, y2, c1, c2, xx, cor, res;
+  double w[2], y, cor, res;
 
   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));
-  SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
-  y1 = (y + t22) - t22;
-  y2 = (y - y1) + dx;
-  c1 = (cs + t22) - t22;
-  c2 = (cs - c1) + ccs;
-  cor = (ssn + s * ccs + cs * s + c2 * y + c1 * y2 - sn * y * dx) - sn * c;
-  y = sn + c1 * y1;
-  cor = cor + ((sn - y) + c1 * y1);
-  res = y + cor;
-  cor = (y - res) + cor;
-  cor = (cor > 0) ? 1.0005 * cor + 1.1e-24 : 1.0005 * cor - 1.1e-24;
+  res = do_sin_slow (u, y, dx, 1.1e-24, &cor);
   if (res == res + cor)
     return (x > 0) ? res : -res;
   else
@@ -1073,27 +1031,13 @@ SECTION
 bsloww2 (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;
+  double w[2], y, cor, res;
 
   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 = y * dx + xx * (cs2 + xx * (cs4 + xx * cs6));
-  SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
-
-  y1 = (y + t22) - t22;
-  y2 = (y - y1) + dx;
-  e1 = (sn + t22) - t22;
-  e2 = (sn - e1) + ssn;
-  cor = (ccs - cs * c - e1 * y2 - e2 * y) - sn * s;
-  y = cs - e1 * y1;
-  cor = cor + ((cs - y) - e1 * y1);
-  res = y + cor;
-  cor = (y - res) + cor;
-  cor = (cor > 0) ? 1.0005 * cor + 1.1e-24 : 1.0005 * cor - 1.1e-24;
+  res = do_cos_slow (u, y, dx, 1.1e-24, &cor);
   if (res == res + cor)
     return (n & 2) ? -res : res;
   else
@@ -1122,25 +1066,13 @@ SECTION
 cslow2 (double x)
 {
   mynumber u;
-  double sn, ssn, cs, ccs, s, c, w[2], y, y1, y2, e1, e2, xx, cor, res;
+  double w[2], y, cor, res;
 
   y = ABS (x);
   u.x = big + y;
   y = y - (u.x - big);
-  xx = y * y;
-  s = y * xx * (sn3 + xx * sn5);
-  c = xx * (cs2 + xx * (cs4 + xx * cs6));
-  SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
-  y1 = (y + t22) - t22;
-  y2 = y - y1;
-  e1 = (sn + t22) - t22;
-  e2 = (sn - e1) + ssn;
-  cor = (ccs - cs * c - e1 * y2 - e2 * y) - sn * s;
-  y = cs - e1 * y1;
-  cor = cor + ((cs - y) - e1 * y1);
-  res = y + cor;
-  cor = (y - res) + cor;
-  if (res == res + 1.0005 * cor)
+  res = do_cos_slow (u, y, 0, 0, &cor);
+  if (res == res + cor)
     return res;
   else
     {
@@ -1235,28 +1167,11 @@ SECTION
 csloww1 (double x, double dx, double orig, int m)
 {
   mynumber u;
-  double sn, ssn, cs, ccs, s, c, w[2], y, y1, y2, c1, c2, xx, cor, res;
+  double w[2], y, cor, res;
 
   u.x = big + x;
   y = x - (u.x - big);
-  xx = y * y;
-  s = y * xx * (sn3 + xx * sn5);
-  c = xx * (cs2 + xx * (cs4 + xx * cs6));
-  SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
-  y1 = (y + t22) - t22;
-  y2 = (y - y1) + dx;
-  c1 = (cs + t22) - t22;
-  c2 = (cs - c1) + ccs;
-  cor = (ssn + s * ccs + cs * s + c2 * y + c1 * y2 - sn * y * dx) - sn * c;
-  y = sn + c1 * y1;
-  cor = cor + ((sn - y) + c1 * y1);
-  res = y + cor;
-  cor = (y - res) + cor;
-
-  if (cor > 0)
-    cor = 1.0005 * cor + 3.1e-30 * ABS (orig);
-  else
-    cor = 1.0005 * cor - 3.1e-30 * ABS (orig);
+  res = do_sin_slow (u, y, dx, 3.1e-30 * ABS (orig), &cor);
 
   if (res == res + cor)
     return (m > 0) ? res : -res;
@@ -1287,29 +1202,11 @@ SECTION
 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;
+  double w[2], y, cor, res;
 
   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));
-  SINCOS_TABLE_LOOKUP (u, sn, ssn, cs, ccs);
-
-  y1 = (y + t22) - t22;
-  y2 = (y - y1) + dx;
-  e1 = (sn + t22) - t22;
-  e2 = (sn - e1) + ssn;
-  cor = (ccs - cs * c - e1 * y2 - e2 * y) - sn * s;
-  y = cs - e1 * y1;
-  cor = cor + ((cs - y) - e1 * y1);
-  res = y + cor;
-  cor = (y - res) + cor;
-
-  if (cor > 0)
-    cor = 1.0005 * cor + 3.1e-30 * ABS (orig);
-  else
-    cor = 1.0005 * cor - 3.1e-30 * ABS (orig);
+  res = do_cos_slow (u, y, dx, 3.1e-30 * ABS (orig), &cor);
 
   if (res == res + cor)
     return (n) ? -res : res;