//===-- RuntimeLib.lc - LLVM Standard C Runtime Library -----------*- C -*-===//
// 
// This file contains definitions of C functions that are useful to get LLVM
// programs up and running.  This library of functions is automatically linked
// into programs loaded into LLI.
//
// This file is compiled by the LLVM port of GCC to get LLVM code.
//
// A lot of this code is ripped gratuitously from glibc and libiberty.
//
//===----------------------------------------------------------------------===//

#include <stdlib.h>

// Prototypes for functions exported by LLI directly.
void exit(int Code);
int putchar(int);
void *malloc(unsigned);
void free(void *);

#define isspace(x) ((x) == ' ' || (x) == '\t' || (x) == '\n')
#define isdigit(x) ((x) >= '0' && (x) <= '9')
#define isupper(x) ((x) >= 'A' && (x) <= 'Z')
#define islower(x) ((x) >= 'a' && (x) <= 'z')
#define isalpha(x) (isupper(x) || islower(x))

// The puts() function writes the string pointed to by s, followed by a 
// NEWLINE character, to the standard output stream stdout. On success the 
// number of characters written is returned; otherwise they return EOF.
//
int puts(const char *S) {
  const char *Str = S;
  while (*Str) putchar(*Str++);
  putchar('\n');
  return Str+1-S;
}


#ifndef ULONG_MAX
#define ULONG_MAX       ((unsigned long)(~0L))          /* 0xFFFFFFFF */
#endif

#ifndef LONG_MAX
#define LONG_MAX        ((long)(ULONG_MAX >> 1))        /* 0x7FFFFFFF */
#endif

#ifndef LONG_MIN
#define LONG_MIN        ((long)(~LONG_MAX))             /* 0x80000000 */
#endif

/*
 * Convert a string to a long integer.
 *
 * Ignores `locale' stuff.  Assumes that the upper and lower case
 * alphabets and digits are each contiguous.
 */
long strtol(const char *nptr, char **endptr, int base) {
        register const char *s = nptr;
        register unsigned long acc;
        register int c;
        register unsigned long cutoff;
        register int neg = 0, any, cutlim;

        /*
         * Skip white space and pick up leading +/- sign if any.
         * If base is 0, allow 0x for hex and 0 for octal, else
         * assume decimal; if base is already 16, allow 0x.
         */
        do {
                c = *s++;
        } while (isspace(c));
        if (c == '-') {
                neg = 1;
                c = *s++;
        } else if (c == '+')
                c = *s++;
        if ((base == 0 || base == 16) &&
            c == '0' && (*s == 'x' || *s == 'X')) {
                c = s[1];
                s += 2;
                base = 16;
        }
        if (base == 0)
                base = c == '0' ? 8 : 10;

        /*
         * Compute the cutoff value between legal numbers and illegal
         * numbers.  That is the largest legal value, divided by the
         * base.  An input number that is greater than this value, if
         * followed by a legal input character, is too big.  One that
         * is equal to this value may be valid or not; the limit
         * between valid and invalid numbers is then based on the last
         * digit.  For instance, if the range for longs is
         * [-2147483648..2147483647] and the input base is 10,
         * cutoff will be set to 214748364 and cutlim to either
         * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
         * a value > 214748364, or equal but the next digit is > 7 (or 8),
         * the number is too big, and we will return a range error.
         *
         * Set any if any `digits' consumed; make it negative to indicate
         * overflow.
         */
        cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
        cutlim = cutoff % (unsigned long)base;
        cutoff /= (unsigned long)base;
        for (acc = 0, any = 0;; c = *s++) {
                if (isdigit(c))
                        c -= '0';
                else if (isalpha(c))
                        c -= isupper(c) ? 'A' - 10 : 'a' - 10;
                else
                        break;
                if (c >= base)
                        break;
                if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
                        any = -1;
                else {
                        any = 1;
                        acc *= base;
                        acc += c;
                }
        }
        if (any < 0) {
                acc = neg ? LONG_MIN : LONG_MAX;
        } else if (neg)
                acc = -acc;
        if (endptr != 0)
                *endptr = (char *) (any ? s - 1 : nptr);
        return (acc);
}


/* Convert a string to an int.  */
int atoi(const char *nptr) {
  return (int)strtol(nptr, 0, 10);
}

/* Convert a string to a long int.  */
long int atol(const char *nptr) {
  return strtol(nptr, 0, 10);
}


unsigned strlen(const char *Str) {
  int Count = 0;
  while (*Str) { ++Count; ++Str; }
  return Count;
}

char *strdup(const char *str) {
  int Len = strlen(str);
  char *Result = (char*)malloc((Len+1)*sizeof(char));
  memcpy(Result, str, Len+1);
  return Result;
}


/* Compare S1 and S2, returning less than, equal to or
   greater than zero if S1 is lexicographically less than,
   equal to or greater than S2.  */
int strcmp (const char *p1, const char *p2) {
  register const unsigned char *s1 = (const unsigned char *) p1;
  register const unsigned char *s2 = (const unsigned char *) p2;
  unsigned char c1, c2;

  do
    {
      c1 = (unsigned char) *s1++;
      c2 = (unsigned char) *s2++;
      if (c1 == '\0')
        return c1 - c2;
    }
  while (c1 == c2);

  return c1 - c2;
}


//===----------------------------------------------------------------------===//
// memory stuff...
//===----------------------------------------------------------------------===//
// http://sources.redhat.com/cgi-bin/cvsweb.cgi/libc/sysdeps/generic/?cvsroot=glibc

typedef unsigned int op_t;
#define OPSIZ 4

void *memset (void *dstpp, int c, size_t len) {
  long long int dstp = (long long int) dstpp;

  if (len >= 8)
    {
      size_t xlen;
      op_t cccc;

      cccc = (unsigned char) c;
      cccc |= cccc << 8;
      cccc |= cccc << 16;
      if (OPSIZ > 4)
        /* Do the shift in two steps to avoid warning if long has 32 bits.  */
        cccc |= (cccc << 16) << 16;

      /* There are at least some bytes to set.
         No need to test for LEN == 0 in this alignment loop.  */
      while (dstp % OPSIZ != 0)
        {
          ((unsigned char *) dstp)[0] = c;
          dstp += 1;
          len -= 1;
        }

      /* Write 8 `op_t' per iteration until less than 8 `op_t' remain.  */
      xlen = len / (OPSIZ * 8);
      while (xlen > 0)
        {
          ((op_t *) dstp)[0] = cccc;
          ((op_t *) dstp)[1] = cccc;
          ((op_t *) dstp)[2] = cccc;
          ((op_t *) dstp)[3] = cccc;
          ((op_t *) dstp)[4] = cccc;
          ((op_t *) dstp)[5] = cccc;
          ((op_t *) dstp)[6] = cccc;
          ((op_t *) dstp)[7] = cccc;
          dstp += 8 * OPSIZ;
          xlen -= 1;
        }
      len %= OPSIZ * 8;

      /* Write 1 `op_t' per iteration until less than OPSIZ bytes remain.  */
      xlen = len / OPSIZ;
      while (xlen > 0)
        {
          ((op_t *) dstp)[0] = cccc;
          dstp += OPSIZ;
          xlen -= 1;
        }
      len %= OPSIZ;
    }

  /* Write the last few bytes.  */
  while (len > 0)
    {
      ((unsigned char *) dstp)[0] = c;
      dstp += 1;
      len -= 1;
    }

  return dstpp;
}

void *memcpy(void *dstpp, const void *srcpp, size_t len) {
  char *dstp = (char*)dstpp;
  char *srcp = (char*) srcpp;
  unsigned i;

  for (i = 0; i < len; ++i)
    dstp[i] = srcp[i];

  return dstpp;
}

void *calloc(size_t nelem, size_t elsize) {
  void *Result = malloc(nelem*elsize);
  return memset(Result, 0, nelem*elsize);
}


//===----------------------------------------------------------------------===//
// libm stuff...
//===----------------------------------------------------------------------===//