try to fix rust-lang#170

Signed-off-by: Benjamin Schultzer <[email protected]>

Author: Schultzer

src/math/jnf.rs

@@ -75,14 +75,14 @@ pub fn jnf(n: i32, mut x: f32) -> f32 {
             }
             temp = 0.5 * x;
             b = temp;
-            a = 1.0;
+            let mut a = 1;
             i = 2;
             while i <= nm1 + 1 {
-                a *= i as f32; /* a = n! */
+                a *= i; /* a = n! */
                 b *= temp; /* b = (x/2)^n */
                 i += 1;
             }
-            b = b / a;
+            b /= a as f32;
         } else {
             /* use backward recurrence */
             /*                      x      x^2      x^2
@@ -124,7 +124,7 @@ pub fn jnf(n: i32, mut x: f32) -> f32 {
             let mut k: i32;
 
             nf = (nm1 as f32) + 1.0;
-            w = 2.0 * (nf as f32) / x;
+            w = 2.0 * nf / x;
             h = 2.0 / x;
             z = w + h;
             q0 = w;

src/math/logf.rs

@@ -29,6 +29,10 @@ pub fn logf(mut x: f32) -> f32 {
     let mut ix = x.to_bits();
     let mut k = 0i32;
 
+    /* Fix sign of zero with downward rounding when x==1.  */
+	if (ix == 0x3f800000) {
+		return 0.;
+    }
     if (ix < 0x00800000) || ((ix >> 31) != 0) {
         /* x < 2**-126  */
         if ix << 1 == 0 {