e_exp: Fixed compiler warning on Visual Studio.
diff --git a/src/libm/e_exp.c b/src/libm/e_exp.c
index 07f630a..84b190b 100644
--- a/src/libm/e_exp.c
+++ b/src/libm/e_exp.c
@@ -126,7 +126,7 @@ double __ieee754_exp(double x) /* default IEEE double exp */
if(hx < 0x3FF0A2B2) { /* and |x| < 1.5 ln2 */
hi = x-ln2HI[xsb]; lo=ln2LO[xsb]; k = 1-xsb-xsb;
} else {
- k = invln2*x+halF[xsb];
+ k = (int32_t) (invln2*x+halF[xsb]);
t = k;
hi = x - t*ln2HI[0]; /* t*ln2HI is exact here */
lo = t*ln2LO[0];