Get rid of libc, take just parts of it

1 files changed, 96 insertions, 0 deletions

diff --git a/third_party/newlib/string/memset.c b/third_party/newlib/string/memset.c
new file mode 100644
index 0000000..e8e667a
--- /dev/null
+++ b/third_party/newlib/string/memset.c
@@ -0,0 +1,96 @@
+/*
+FUNCTION
+	<<memset>>---set an area of memory
+
+INDEX
+	memset
+
+SYNOPSIS
+	#include <string.h>
+	void *memset(void *<[dst]>, int <[c]>, size_t <[length]>);
+
+DESCRIPTION
+	This function converts the argument <[c]> into an unsigned
+	char and fills the first <[length]> characters of the array
+	pointed to by <[dst]> to the value.
+
+RETURNS
+	<<memset>> returns the value of <[dst]>.
+
+PORTABILITY
+<<memset>> is ANSI C.
+
+    <<memset>> requires no supporting OS subroutines.
+
+QUICKREF
+	memset ansi pure
+*/
+
+#include <string.h>
+#include "local.h"
+
+#define LBLOCKSIZE (sizeof(long))
+#define UNALIGNED(X)   ((long)X & (LBLOCKSIZE - 1))
+#define TOO_SMALL(LEN) ((LEN) < LBLOCKSIZE)
+
+void *
+__inhibit_loop_to_libcall
+memset (void *m,
+	int c,
+	size_t n)
+{
+  char *s = (char *) m;
+
+#if !defined(PREFER_SIZE_OVER_SPEED) && !defined(__OPTIMIZE_SIZE__)
+  unsigned int i;
+  unsigned long buffer;
+  unsigned long *aligned_addr;
+  unsigned int d = c & 0xff;	/* To avoid sign extension, copy C to an
+				   unsigned variable.  */
+
+  while (UNALIGNED (s))
+    {
+      if (n--)
+        *s++ = (char) c;
+      else
+        return m;
+    }
+
+  if (!TOO_SMALL (n))
+    {
+      /* If we get this far, we know that n is large and s is word-aligned. */
+      aligned_addr = (unsigned long *) s;
+
+      /* Store D into each char sized location in BUFFER so that
+         we can set large blocks quickly.  */
+      buffer = (d << 8) | d;
+      buffer |= (buffer << 16);
+      for (i = 32; i < LBLOCKSIZE * 8; i <<= 1)
+        buffer = (buffer << i) | buffer;
+
+      /* Unroll the loop.  */
+      while (n >= LBLOCKSIZE*4)
+        {
+          *aligned_addr++ = buffer;
+          *aligned_addr++ = buffer;
+          *aligned_addr++ = buffer;
+          *aligned_addr++ = buffer;
+          n -= 4*LBLOCKSIZE;
+        }
+
+      while (n >= LBLOCKSIZE)
+        {
+          *aligned_addr++ = buffer;
+          n -= LBLOCKSIZE;
+        }
+      /* Pick up the remainder with a bytewise loop.  */
+      s = (char*)aligned_addr;
+    }
+
+#endif /* not PREFER_SIZE_OVER_SPEED */
+
+  while (n--)
+    *s++ = (char) c;
+
+  return m;
+}