-/***
- *** SQRTF: single-precision square root
- ***/
-#if 0 /* _mesa_sqrtf() not accurate enough - temporarily disabled */
-# define SQRTF(X) _mesa_sqrtf(X)
+/**
+ * \name Work-arounds for platforms that lack C99 math functions
+ */
+/*@{*/
+#if (!defined(_XOPEN_SOURCE) || (_XOPEN_SOURCE < 600)) && !defined(_ISOC99_SOURCE) \
+ && (!defined(__STDC_VERSION__) || (__STDC_VERSION__ < 199901L)) \
+ && (!defined(_MSC_VER) || (_MSC_VER < 1400))
+#define acosf(f) ((float) acos(f))
+#define asinf(f) ((float) asin(f))
+#define atan2f(x,y) ((float) atan2(x,y))
+#define atanf(f) ((float) atan(f))
+#define ceilf(f) ((float) ceil(f))
+#define cosf(f) ((float) cos(f))
+#define coshf(f) ((float) cosh(f))
+#define expf(f) ((float) exp(f))
+#define exp2f(f) ((float) exp2(f))
+#define floorf(f) ((float) floor(f))
+#define logf(f) ((float) log(f))
+
+#ifdef ANDROID
+#define log2f(f) (logf(f) * (float) (1.0 / M_LN2))