1 files changed, 85 insertions, 0 deletions
diff --git a/src/Runtime/__mem.c b/src/Runtime/__mem.c
new file mode 100644
index 0000000..a5ef6c1
--- /dev/null
+++ b/src/Runtime/__mem.c
@@ -0,0 +1,85 @@
+#include "string.h"
+
+void* memcpy(void* dst, const void* src, size_t n) {
+  const char* p;
+  char* q;
+  int rev = ((unsigned long)src < (unsigned long)dst);
+
+  if (!rev) {
+
+    for (p = (const char*)src - 1, q = (char*)dst - 1, n++; --n;)
+      *++q = *++p;
+
+  } else {
+    for (p = (const char*)src + n, q = (char*)dst + n, n++; --n;)
+      *--q = *--p;
+  }
+  return (dst);
+}
+
+#define cps ((unsigned char*)src)
+#define cpd ((unsigned char*)dst)
+#define lps ((unsigned long*)src)
+#define lpd ((unsigned long*)dst)
+#define deref_auto_inc(p) *++(p)
+
+void __fill_mem(void* dst, int val, size_t n) {
+  unsigned long v = (unsigned char)val;
+  unsigned long i;
+
+  cpd = ((unsigned char*)dst) - 1;
+
+  if (n >= 32) {
+    i = (~(unsigned long)dst) & 3;
+
+    if (i) {
+      n -= i;
+
+      do
+        deref_auto_inc(cpd) = v;
+      while (--i);
+    }
+
+    if (v)
+      v |= v << 24 | v << 16 | v << 8;
+
+    lpd = ((unsigned long*)(cpd + 1)) - 1;
+
+    i = n >> 5;
+
+    if (i)
+      do {
+        deref_auto_inc(lpd) = v;
+        deref_auto_inc(lpd) = v;
+        deref_auto_inc(lpd) = v;
+        deref_auto_inc(lpd) = v;
+        deref_auto_inc(lpd) = v;
+        deref_auto_inc(lpd) = v;
+        deref_auto_inc(lpd) = v;
+        deref_auto_inc(lpd) = v;
+      } while (--i);
+
+    i = (n & 31) >> 2;
+
+    if (i)
+      do
+        deref_auto_inc(lpd) = v;
+      while (--i);
+
+    cpd = ((unsigned char*)(lpd + 1)) - 1;
+
+    n &= 3;
+  }
+
+  if (n)
+    do
+      deref_auto_inc(cpd) = v;
+    while (--n);
+
+  return;
+}
+
+void* memset(void* str, int c, size_t n) {
+  __fill_mem(str, c, n);
+  return str;
+}