added _Complex floating point routines

Author: ZERICO2005

src/crt/dcomplex.c

@@ -0,0 +1,36 @@
+
+// (a + ib) + (c + id)
+_Complex long double __adddc3(long double a, long double b, long double c, long double d) {
+    return (a + c) + (b + d) * 1.0iL;
+}
+
+// (a + ib) - (c + id)
+_Complex long double __subdc3(long double a, long double b, long double c, long double d) {
+    return (a - c) + (b - d) * 1.0iL;
+}
+
+// (a + ib) * (c + id)
+_Complex long double __muldc3(long double a, long double b, long double c, long double d) {
+    return (a * c - b * d) + (a * d + b * c) * 1.0iL;
+}
+
+// (a + ib) / (c + id)
+// Uses stable algorithm to avoid overflow/underflow issues
+_Complex long double __divdc3(long double a, long double b, long double c, long double d) {
+    long double r, den;
+    long double real, imag;
+
+    if (__builtin_fabsl(c) >= __builtin_fabsl(d)) {
+        r   = d / c;
+        den = c + d * r;
+        real = (a + b * r) / den;
+        imag = (b - a * r) / den;
+    } else {
+        r   = c / d;
+        den = d + c * r;
+        real = (a * r + b) / den;
+        imag = (b * r - a) / den;
+    }
+
+    return real + imag * 1.0iL;
+}

src/crt/fcomplex.c

@@ -0,0 +1,36 @@
+
+// (a + ib) + (c + id)
+_Complex float __addsc3(float a, float b, float c, float d) {
+    return (a + c) + (b + d) * 1.0iF;
+}
+
+// (a + ib) - (c + id)
+_Complex float __subsc3(float a, float b, float c, float d) {
+    return (a - c) + (b - d) * 1.0iF;
+}
+
+// (a + ib) * (c + id)
+_Complex float __mulsc3(float a, float b, float c, float d) {
+    return (a * c - b * d) + (a * d + b * c) * 1.0iF;
+}
+
+// (a + ib) / (c + id)
+// Uses stable algorithm to avoid overflow/underflow issues
+_Complex float __divsc3(float a, float b, float c, float d) {
+    float r, den;
+    float real, imag;
+
+    if (__builtin_fabsf(c) >= __builtin_fabsf(d)) {
+        r   = d / c;
+        den = c + d * r;
+        real = (a + b * r) / den;
+        imag = (b - a * r) / den;
+    } else {
+        r   = c / d;
+        den = d + c * r;
+        real = (a * r + b) / den;
+        imag = (b * r - a) / den;
+    }
+
+    return real + imag * 1.0iF;
+}