added double precision tests

tests/transcendentals-8-3.ispc

@@ -0,0 +1,23 @@
+static double double4(uniform double a, uniform double b, uniform double c, 
+                    uniform double d) {
+    double ret = 0;
+    for (uniform int i = 0; i < programCount; i += 4) {
+        ret = insert(ret, i + 0, a);
+        ret = insert(ret, i + 1, b);
+        ret = insert(ret, i + 2, c);
+        ret = insert(ret, i + 3, d);
+    }
+    return ret;
+}
+
+export uniform int width() { return programCount; }
+
+
+bool ok(double x, double ref) { return (abs(x - ref) < 1d-16) || abs((x-ref)/ref) < 1d-15; }
+
+export void f_v(uniform float RET[]) {
+    double v = double4((14.300000190734863d0),(-6.699999809265137d0),(-21.200000762939453d0),(9.000000000000000d0));
+    double ref = double4((1623346.2946371625d0),(0.001230912137451317d0),(6.208070673019769d-10),(8103.083927575384d0));
+    RET[programIndex] = ok(exp(v), ref) ? 1. : 0.;
+}
+export void result(uniform float RET[]) { RET[programIndex] = 1.; }