1 files changed, 59 insertions, 0 deletions

diff --git a/src/string.c b/src/string.c
new file mode 100644
index 0000000..4801154
--- /dev/null
+++ b/src/string.c
@@ -0,0 +1,59 @@
+#include <string.h>
+
+#include <stdint.h>
+
+void* memcpy(void* dst, const void* src, size_t count) {
+  // TODO: Can probably use better implementations based on hw instruction set.
+  uint32_t*       dst32 = (uint32_t*)dst;
+  const uint32_t* src32 = (uint32_t*)src;
+  for(; count >= 4; count -= 4) {
+    *dst32++ = *src32++;
+  }
+  uint8_t*       dst8 = (uint8_t*)dst32;
+  const uint8_t* src8 = (uint8_t*)src32;
+  for(; count != 0; count--) {
+    *dst8++ = *src8++;
+  }
+  return dst8;
+}
+
+static int count_digits_u(unsigned int x) {
+  int count = 0;
+  for(; x != 0; x /= 10, count++);
+  return count;
+}
+
+char* utoa(unsigned int x, char* buffer, size_t size) {
+  if (size > 0) {
+    const int num_digits = count_digits_u(x);
+    size_t i = 0;
+    while ((x != 0) && ((i+1) < size)) {
+      const unsigned int digit = x % 10;
+      x /= 10;
+      buffer[num_digits-1 - i++] = '0' + digit;
+    }
+    buffer[i] = 0;
+  }
+  return buffer;
+}
+
+char* ptoa(const void* ptr, char* buffer, size_t size) {
+  if (size > 2) {
+    size_t i = 0;
+    buffer[i++] = '0';
+    buffer[i++] = 'x';
+    uintptr_t x = (uintptr_t)ptr;
+    const int num_digits = count_digits_u(x);
+    while ((x != 0) && (i < size)) {
+      const unsigned int digit = x % 16;
+      x /= 16;
+      const char hex = (digit < 10) ? ('0' + digit) : ('a' + (digit-10));
+      buffer[num_digits-1+2 - i++] = hex;
+    }
+    buffer[i] = 0;
+  } else if (size > 0) {
+    buffer[0] = 0;
+  }
+  return buffer;
+}
+