change reference_relaxed_exp to use float type to calculate reference…

… value

test_conformance/math_brute_force/reference_math.cpp

@@ -5084,7 +5084,10 @@ static long double reference_scalblnl(long double x, long n)
 #endif
 }
 
-double reference_relaxed_exp(double x) { return reference_exp(x); }
+double reference_relaxed_exp(double x) 
+{ 
+    return reference_exp2(((float)x) * HEX_FLT(+, 1, 715476, +, 0));
+}
 
 double reference_exp(double x)
 {
@@ -5771,4 +5774,4 @@ long double reference_erfcl(long double x) { return erfc(x); }
 long double reference_erfl(long double x) { return erf(x); }
 
 double reference_erfc(double x) { return erfc(x); }
-double reference_erf(double x) { return erf(x); }
+double reference_erf(double x) { return erf(x); }