--- /dev/null
+
+#include <stdbool.h>
+#include <stdint.h>
+#include "platform.h"
+#include "internals.h"
+#include "softfloat.h"
+
+float64_t f64_add( float64_t a, float64_t b )
+{
+ union ui64_f64 uA;
+ uint_fast64_t uiA;
+ bool signA;
+ union ui64_f64 uB;
+ uint_fast64_t uiB;
+ bool signB;
+ float64_t ( *magsRoutine )( uint_fast64_t, uint_fast64_t, bool );
+
+ uA.f = a;
+ uiA = uA.ui;
+ signA = signF64UI( uiA );
+ uB.f = b;
+ uiB = uB.ui;
+ signB = signF64UI( uiB );
+ magsRoutine =
+ ( signA == signB ) ? softfloat_addMagsF64 : softfloat_subMagsF64;
+ return magsRoutine( uiA, uiB, signA );
+
+}
+