1 files changed, 120 insertions, 0 deletions
diff --git a/winsup/cygwin/math/fastmath.h b/winsup/cygwin/math/fastmath.h
new file mode 100644
index 000000000..a6bb467c2
--- /dev/null
+++ b/winsup/cygwin/math/fastmath.h
@@ -0,0 +1,120 @@
+/**
+ * This file has no copyright assigned and is placed in the Public Domain.
+ * This file is part of the mingw-w64 runtime package.
+ * No warranty is given; refer to the file DISCLAIMER.PD within this package.
+ */
+#ifndef _MINGWEX_FASTMATH_H_
+#define _MINGWEX_FASTMATH_H_
+
+/* Fast math inlines
+   No range or domain checks. No setting of errno.  No tweaks to
+   protect precision near range limits. */
+
+/* For now this is an internal header with just the functions that
+   are currently used in building libmingwex.a math components */
+
+/* FIXME: We really should get rid of the code duplication using euther
+   C++ templates or tgmath-type macros.  */  
+
+static __inline__ double __fast_sqrt (double x)
+{
+  double res;
+  asm __volatile__ ("fsqrt" : "=t" (res) : "0" (x));
+  return res;
+}
+
+static __inline__ long double __fast_sqrtl (long double x)
+{
+  long double res;
+  asm __volatile__ ("fsqrt" : "=t" (res) : "0" (x));
+  return res;
+}
+
+static __inline__ float __fast_sqrtf (float x)
+{
+  float res;
+  asm __volatile__ ("fsqrt" : "=t" (res) : "0" (x));
+  return res;
+}
+
+
+static __inline__ double __fast_log (double x)
+{
+   double res;
+   asm __volatile__
+     ("fldln2\n\t"
+      "fxch\n\t"
+      "fyl2x"
+       : "=t" (res) : "0" (x) : "st(1)");
+   return res;
+}
+
+static __inline__ long double __fast_logl (long double x)
+{
+  long double res;
+   asm __volatile__
+     ("fldln2\n\t"
+      "fxch\n\t"
+      "fyl2x"
+       : "=t" (res) : "0" (x) : "st(1)");
+   return res;
+}
+
+
+static __inline__ float __fast_logf (float x)
+{
+   float res;
+   asm __volatile__
+     ("fldln2\n\t"
+      "fxch\n\t"
+      "fyl2x"
+       : "=t" (res) : "0" (x) : "st(1)");
+   return res;
+}
+
+static __inline__ double __fast_log1p (double x)
+{
+  double res;
+  /* fyl2xp1 accurate only for |x| <= 1.0 - 0.5 * sqrt (2.0) */
+  if (fabs (x) >= 1.0 - 0.5 * 1.41421356237309504880)
+    res = __fast_log (1.0 + x);
+  else
+    asm __volatile__
+      ("fldln2\n\t"
+       "fxch\n\t"
+       "fyl2xp1"
+       : "=t" (res) : "0" (x) : "st(1)");
+   return res;
+}
+
+static __inline__ long double __fast_log1pl (long double x)
+{
+  long double res;
+  /* fyl2xp1 accurate only for |x| <= 1.0 - 0.5 * sqrt (2.0) */
+  if (fabsl (x) >= 1.0L - 0.5L * 1.41421356237309504880L)
+    res = __fast_logl (1.0L + x);
+  else
+    asm __volatile__
+      ("fldln2\n\t"
+       "fxch\n\t"
+       "fyl2xp1"
+       : "=t" (res) : "0" (x) : "st(1)");
+   return res;
+}
+
+static __inline__ float __fast_log1pf (float x)
+{
+  float res;
+  /* fyl2xp1 accurate only for |x| <= 1.0 - 0.5 * sqrt (2.0) */
+  if (fabsf (x) >= 1.0 - 0.5 * 1.41421356237309504880)
+    res = __fast_logf (1.0 + x);
+  else
+    asm __volatile__
+      ("fldln2\n\t"
+       "fxch\n\t"
+       "fyl2xp1"
+       : "=t" (res) : "0" (x) : "st(1)");
+   return res;
+}
+
+#endif