Consolidate reduce_and_compute code

This patch reshuffles the reduce_and_compute code so that the
structure matches other code structures of the same type elsewhere in
s_sin.c and s_sincos.c.  This is the beginning of an attempt to
consolidate and reduce code duplication in functions in s_sin.c to
make it easier to read and possibly also easier for the compiler to
optimize.

	* sysdeps/ieee754/dbl-64/s_sin.c (reduce_and_compute):
	Consolidate switch cases 0 and 2.

2 files changed, 19 insertions, 17 deletions

diff --git a/ChangeLog b/ChangeLog
index 73b2ed0e5e..dec058d7a6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2016-08-30  Siddhesh Poyarekar  <siddhesh@sourceware.org>
+
+	* sysdeps/ieee754/dbl-64/s_sin.c (reduce_and_compute):
+	Consolidate switch cases 0 and 2.
+
 2016-08-29  Paul E. Murphy  <murphyp@linux.vnet.ibm.com>
 
 	* math/Makefile (libm-gen-calls): Add cpow, clog, clog10, cexp, cproj.
diff --git a/sysdeps/ieee754/dbl-64/s_sin.c b/sysdeps/ieee754/dbl-64/s_sin.c
index 7c9a07990f..e1ee7a980b 100644
--- a/sysdeps/ieee754/dbl-64/s_sin.c
+++ b/sysdeps/ieee754/dbl-64/s_sin.c
@@ -249,23 +249,20 @@ reduce_and_compute (double x, unsigned int k)
   k = (n + k) % 4;
   switch (k)
     {
-      case 0:
-	if (a * a < 0.01588)
-	  retval = bsloww (a, da, x, n);
-	else
-	  retval = bsloww1 (a, da, x, n);
-	break;
-      case 2:
-	if (a * a < 0.01588)
-	  retval = bsloww (-a, -da, x, n);
-	else
-	  retval = bsloww1 (-a, -da, x, n);
-	break;
-
-      case 1:
-      case 3:
-	retval = bsloww2 (a, da, x, n);
-	break;
+    case 2:
+      a = -a;
+      da = -da;
+    case 0:
+      if (a * a < 0.01588)
+	retval = bsloww (a, da, x, n);
+      else
+	retval = bsloww1 (a, da, x, n);
+      break;
+
+    case 1:
+    case 3:
+      retval = bsloww2 (a, da, x, n);
+      break;
     }
   return retval;
 }