Trigonometric optimizations for POWER

1 files changed, 117 insertions, 0 deletions

diff --git a/sysdeps/powerpc/fpu/e_hypot.c b/sysdeps/powerpc/fpu/e_hypot.c
new file mode 100644
index 0000000000..22bd56371e
--- /dev/null
+++ b/sysdeps/powerpc/fpu/e_hypot.c
@@ -0,0 +1,117 @@
+/* Pythagorean addition using doubles
+   Copyright (C) 2011 Free Software Foundation, Inc.
+   This file is part of the GNU C Library
+   Contributed by Adhemerval Zanella <azanella@br.ibm.com>, 2011
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include "math.h"
+#include "math_private.h"
+
+static const double two60   = 1.152921504606847e+18;
+static const double two500  = 3.2733906078961419e+150;
+static const double two600  = 4.149515568880993e+180;
+static const double two1022 = 4.49423283715579e+307;
+static const double twoM500 = 3.054936363499605e-151;
+static const double twoM600 = 4.616489308892868e-128;
+static const double pdnum   = 2.225073858507201e-308;
+
+/* __ieee754_hypot(x,y)
+ *
+ * This a FP only version without any FP->INT conversion.
+ * It is similar to default C version, making appropriates
+ * overflow and underflows checks as well scaling when it
+ * is needed.
+ */
+
+#ifdef _ARCH_PWR7
+/* POWER7 isinf and isnan optimization are fast. */
+# define TEST_INF_NAN(x, y)                                       \
+   if (isinf(x) || isinf(y))                                      \
+       return INFINITY;                                           \
+   if (isnan(x) || isnan(y))                                      \
+       return NAN;
+# else
+/* For POWER6 and below isinf/isnan triggers LHS and PLT calls are
+ * costly (especially for POWER6). */
+# define GET_TW0_HIGH_WORD(d1,d2,i1,i2)                           \
+ do {                                                             \
+   ieee_double_shape_type gh_u1;                                  \
+   ieee_double_shape_type gh_u2;                                  \
+   gh_u1.value = (d1);                                            \
+   gh_u2.value = (d2);                                            \
+   (i1) = gh_u1.parts.msw;                                        \
+   (i2) = gh_u2.parts.msw;                                        \
+ } while (0)
+
+# define TEST_INF_NAN(x, y)                                      \
+ do {                                                            \
+   int32_t hx, hy;                                               \
+   GET_TW0_HIGH_WORD(x, y, hx, hy);                              \
+   if (hy > hx) {                                                \
+     uint32_t ht = hx; hx = hy; hy = ht;                         \
+   }                                                             \
+   if (hx >= 0x7ff00000) {                                       \
+     if (hx == 0x7ff00000 || hy == 0x7ff00000)                   \
+       return INFINITY;                                          \
+     return NAN;                                                 \
+   }                                                             \
+ } while (0)
+
+#endif
+
+
+double
+__ieee754_hypot (double x, double y)
+{
+  x = fabs (x);
+  y = fabs (y);
+
+  TEST_INF_NAN (x, y);
+
+  if (y > x)
+    {
+      double t = x;
+      x = y;
+      y = t;
+    }
+  if (y == 0.0 || (x / y) > two60)
+    {
+      return x + y;
+    }
+  if (x > two500)
+    {
+      x *= twoM600;
+      y *= twoM600;
+      return sqrt (x * x + y * y) / twoM600;
+    }
+  if (y < twoM500)
+    {
+      if (y <= pdnum)
+	{
+	  x *= two1022;
+	  y *= two1022;
+	  return sqrt (x * x + y * y) / two1022;
+	}
+      else
+	{
+	  x *= two600;
+	  y *= two600;
+	  return sqrt (x * x + y * y) / two600;
+	}
+    }
+  return sqrt (x * x + y * y);
+}