build: add fminf() emulation

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

configure

@@ -1645,6 +1645,7 @@ MATH_FUNCS="
     exp2
     exp2f
     expf
+    fminf
     isinf
     isnan
     ldexpf
@@ -4635,6 +4636,7 @@ disabled crystalhd || check_lib libcrystalhd/libcrystalhd_if.h DtsCrystalHDVersi
 atan2f_args=2
 ldexpf_args=2
 powf_args=2
+fminf_args=2
 
 for func in $MATH_FUNCS; do
     eval check_mathfunc $func \${${func}_args:-1}

libavutil/libm.h

@@ -82,6 +82,11 @@ static av_always_inline float cbrtf(float x)
 #define exp2f(x) ((float)exp2(x))
 #endif /* HAVE_EXP2F */
 
+#if !HAVE_FMINF
+#undef fminf
+#define fminf(x, y) ((float)fminf(x,y))
+#endif
+
 #if !HAVE_ISINF
 static av_always_inline av_const int isinf(float x)
 {