Rename jerry-libm to jerry-math (#4410)

That "libm" in the name of the library resulted in awkward naming
on *nix systems (`libjerry-libm.*`, "lib" occurring twice). And the
name of the corresponding header is `math.h` anyway.

Note that this is a breaking change in some sense. The commit
contains no API change, but the build system does change for users
of the math library.

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu

1 files changed, 144 insertions, 0 deletions

diff --git a/jerry-math/acos.c b/jerry-math/acos.c
new file mode 100644
index 00000000..7a44b951
--- /dev/null
+++ b/jerry-math/acos.c
@@ -0,0 +1,144 @@
+/* Copyright JS Foundation and other contributors, http://js.foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * This file is based on work under the following copyright and permission
+ * notice:
+ *
+ *     Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ *     Developed at SunSoft, a Sun Microsystems, Inc. business.
+ *     Permission to use, copy, modify, and distribute this
+ *     software is freely granted, provided that this notice
+ *     is preserved.
+ *
+ *     @(#)e_acos.c 1.3 95/01/18
+ */
+
+#include "jerry-math-internal.h"
+
+/* acos(x)
+ *
+ * Method:
+ *      acos(x)  = pi/2 - asin(x)
+ *      acos(-x) = pi/2 + asin(x)
+ * For |x|<=0.5
+ *      acos(x) = pi/2 - (x + x*x^2*R(x^2))     (see asin.c)
+ * For x>0.5
+ *      acos(x) = pi/2 - (pi/2 - 2asin(sqrt((1-x)/2)))
+ *              = 2asin(sqrt((1-x)/2))
+ *              = 2s + 2s*z*R(z)        ...z=(1-x)/2, s=sqrt(z)
+ *              = 2f + (2c + 2s*z*R(z))
+ *     where f=hi part of s, and c = (z-f*f)/(s+f) is the correction term
+ *     for f so that f+c ~ sqrt(z).
+ * For x<-0.5
+ *      acos(x) = pi - 2asin(sqrt((1-|x|)/2))
+ *              = pi - 0.5*(s+s*z*R(z)), where z=(1-|x|)/2,s=sqrt(z)
+ *
+ * Special cases:
+ *      if x is NaN, return x itself;
+ *      if |x|>1, return NaN with invalid signal.
+ *
+ * Function needed: sqrt
+ */
+
+#define one      1.00000000000000000000e+00 /* 0x3FF00000, 0x00000000 */
+#define pi       3.14159265358979311600e+00 /* 0x400921FB, 0x54442D18 */
+#define pio2_hi  1.57079632679489655800e+00 /* 0x3FF921FB, 0x54442D18 */
+#define pio2_lo  6.12323399573676603587e-17 /* 0x3C91A626, 0x33145C07 */
+#define pS0      1.66666666666666657415e-01 /* 0x3FC55555, 0x55555555 */
+#define pS1     -3.25565818622400915405e-01 /* 0xBFD4D612, 0x03EB6F7D */
+#define pS2      2.01212532134862925881e-01 /* 0x3FC9C155, 0x0E884455 */
+#define pS3     -4.00555345006794114027e-02 /* 0xBFA48228, 0xB5688F3B */
+#define pS4      7.91534994289814532176e-04 /* 0x3F49EFE0, 0x7501B288 */
+#define pS5      3.47933107596021167570e-05 /* 0x3F023DE1, 0x0DFDF709 */
+#define qS1     -2.40339491173441421878e+00 /* 0xC0033A27, 0x1C8A2D4B */
+#define qS2      2.02094576023350569471e+00 /* 0x40002AE5, 0x9C598AC8 */
+#define qS3     -6.88283971605453293030e-01 /* 0xBFE6066C, 0x1B8D0159 */
+#define qS4      7.70381505559019352791e-02 /* 0x3FB3B8C5, 0xB12E9282 */
+
+double
+acos (double x)
+{
+  double z, p, q, r, w, s, c;
+  int hx, ix;
+
+  hx = __HI (x);
+  ix = hx & 0x7fffffff;
+  if (ix >= 0x3ff00000) /* |x| >= 1 */
+  {
+    if (((ix - 0x3ff00000) | __LO (x)) == 0) /* |x| == 1 */
+    {
+      if (hx > 0) /* acos(1) = 0  */
+      {
+        return 0.0;
+      }
+      else /* acos(-1) = pi */
+      {
+        return pi + 2.0 * pio2_lo;
+      }
+    }
+    return NAN; /* acos(|x|>1) is NaN */
+  }
+  if (ix < 0x3fe00000) /* |x| < 0.5 */
+  {
+    if (ix <= 0x3c600000) /* if |x| < 2**-57 */
+    {
+      return pio2_hi + pio2_lo;
+    }
+    z = x * x;
+    p = z * (pS0 + z * (pS1 + z * (pS2 + z * (pS3 + z * (pS4 + z * pS5)))));
+    q = one + z * (qS1 + z * (qS2 + z * (qS3 + z * qS4)));
+    r = p / q;
+    return pio2_hi - (x - (pio2_lo - x * r));
+  }
+  else if (hx < 0) /* x < -0.5 */
+  {
+    z = (one + x) * 0.5;
+    p = z * (pS0 + z * (pS1 + z * (pS2 + z * (pS3 + z * (pS4 + z * pS5)))));
+    q = one + z * (qS1 + z * (qS2 + z * (qS3 + z * qS4)));
+    s = sqrt (z);
+    r = p / q;
+    w = r * s - pio2_lo;
+    return pi - 2.0 * (s + w);
+  }
+  else /* x > 0.5 */
+  {
+    double_accessor df;
+    z = (one - x) * 0.5;
+    s = sqrt (z);
+    df.dbl = s;
+    df.as_int.lo = 0;
+    c = (z - df.dbl * df.dbl) / (s + df.dbl);
+    p = z * (pS0 + z * (pS1 + z * (pS2 + z * (pS3 + z * (pS4 + z * pS5)))));
+    q = one + z * (qS1 + z * (qS2 + z * (qS3 + z * qS4)));
+    r = p / q;
+    w = r * s + c;
+    return 2.0 * (df.dbl + w);
+  }
+} /* acos */
+
+#undef one
+#undef pi
+#undef pio2_hi
+#undef pio2_lo
+#undef pS0
+#undef pS1
+#undef pS2
+#undef pS3
+#undef pS4
+#undef pS5
+#undef qS1
+#undef qS2
+#undef qS3
+#undef qS4