+#define frac_div32(a,b) ((float)(a)/(b))
+
+#ifdef FLOAT_APPROX
+
+/* Note: This assumes radix-2 floating point with the exponent at bits 23..30 and an offset of 127
+ denorm, +/- inf and NaN are *not* handled */
+
+/** Base-2 log approximation (log2(x)). */
+static inline float celt_log2(float x)
+{
+ int integer;
+ float frac;
+ union {
+ float f;
+ celt_uint32 i;
+ } in;
+ in.f = x;
+ integer = (in.i>>23)-127;
+ in.i -= integer<<23;
+ frac = in.f - 1.5f;
+ frac = -0.41445418f + frac*(0.95909232f
+ + frac*(-0.33951290f + frac*0.16541097f));
+ return 1+integer+frac;
+}
+
+/** Base-2 exponential approximation (2^x). */
+static inline float celt_exp2(float x)
+{
+ int integer;
+ float frac;
+ union {
+ float f;
+ celt_uint32 i;
+ } res;
+ integer = floor(x);
+ if (integer < -50)
+ return 0;
+ frac = x-integer;
+ /* K0 = 1, K1 = log(2), K2 = 3-4*log(2), K3 = 3*log(2) - 2 */
+ res.f = 0.99992522f + frac * (0.69583354f
+ + frac * (0.22606716f + 0.078024523f*frac));
+ res.i = (res.i + (integer<<23)) & 0x7fffffff;
+ return res.f;
+}
+
+#else
+#define celt_log2(x) ((float)(1.442695040888963387*log(x)))
+#define celt_exp2(x) ((float)exp(0.6931471805599453094*(x)))
+#endif