Implemented math.h

libc/math/round.c

@@ -0,0 +1,46 @@
+#include <math.h>
+
+double round(double x) {
+    double res;
+    __asm__ volatile (
+        "fldl %1\n"       // Load x to the FPU stack
+        "frndint\n"       // Round to nearest integer
+        "fstpl %0"        // Store result
+        : "=m"(res)
+        : "m"(x)
+    );
+    if ((x - res) == 0.5 || (x - res) == -0.5) {
+        // Halfway cases: round away from zero
+        res += (x > 0) ? 1.0 : -1.0;
+    }
+    return res;
+}
+
+double floor(double x) {
+    double res = round(x);
+    if (res > x) { res -= 1.0; }
+    return res;
+}
+
+double ceil(double x){
+    double res = round(x);
+    if (res < x) { res += 1.0; }
+    return res;
+}
+
+double trunc(double x) {
+    double res = round(x);
+    if (x < 0 && x != res) { res -= 1.0; }
+    return res;
+}
+
+double fmod(double x, double y) {
+    return x - y * floor(x / y);
+}
+
+double modf(double x, double* iptr) {
+    double whole = trunc(x);
+    *iptr = whole;
+    return x - whole;
+}
+