Initial revision

1 files changed, 636 insertions, 0 deletions

diff --git a/gas/atof-generic.c b/gas/atof-generic.c
new file mode 100644
index 0000000000..316f665a45
--- /dev/null
+++ b/gas/atof-generic.c
@@ -0,0 +1,636 @@
+/* atof_generic.c - turn a string of digits into a Flonum
+   Copyright (C) 1987, 90, 91, 92, 93, 94, 95, 96, 1998
+   Free Software Foundation, Inc.
+
+   This file is part of GAS, the GNU Assembler.
+
+   GAS is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   GAS is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GAS; see the file COPYING.  If not, write to
+   the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+#include <ctype.h>
+#include <string.h>
+
+#include "as.h"
+
+#ifndef FALSE
+#define FALSE (0)
+#endif
+#ifndef TRUE
+#define TRUE  (1)
+#endif
+
+#ifdef TRACE
+static void flonum_print PARAMS ((const FLONUM_TYPE *));
+#endif
+
+#define ASSUME_DECIMAL_MARK_IS_DOT
+
+/***********************************************************************\
+ *									*
+ *	Given a string of decimal digits , with optional decimal	*
+ *	mark and optional decimal exponent (place value) of the		*
+ *	lowest_order decimal digit: produce a floating point		*
+ *	number. The number is 'generic' floating point: our		*
+ *	caller will encode it for a specific machine architecture.	*
+ *									*
+ *	Assumptions							*
+ *		uses base (radix) 2					*
+ *		this machine uses 2's complement binary integers	*
+ *		target flonums use "      "         "       "		*
+ *		target flonums exponents fit in a long			*
+ *									*
+ \***********************************************************************/
+
+/*
+
+  Syntax:
+
+  <flonum> ::= <optional-sign> <decimal-number> <optional-exponent>
+  <optional-sign> ::= '+' | '-' | {empty}
+  <decimal-number> ::= <integer>
+  | <integer> <radix-character>
+  | <integer> <radix-character> <integer>
+  | <radix-character> <integer>
+
+  <optional-exponent> ::= {empty}
+  | <exponent-character> <optional-sign> <integer>
+
+  <integer> ::= <digit> | <digit> <integer>
+  <digit> ::= '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9'
+  <exponent-character> ::= {one character from "string_of_decimal_exponent_marks"}
+  <radix-character> ::= {one character from "string_of_decimal_marks"}
+
+  */
+
+int
+atof_generic (address_of_string_pointer,
+	      string_of_decimal_marks,
+	      string_of_decimal_exponent_marks,
+	      address_of_generic_floating_point_number)
+     /* return pointer to just AFTER number we read. */
+     char **address_of_string_pointer;
+     /* At most one per number. */
+     const char *string_of_decimal_marks;
+     const char *string_of_decimal_exponent_marks;
+     FLONUM_TYPE *address_of_generic_floating_point_number;
+{
+  int return_value;		/* 0 means OK. */
+  char *first_digit;
+  unsigned int number_of_digits_before_decimal;
+  unsigned int number_of_digits_after_decimal;
+  long decimal_exponent;
+  unsigned int number_of_digits_available;
+  char digits_sign_char;
+
+  /*
+   * Scan the input string, abstracting (1)digits (2)decimal mark (3) exponent.
+   * It would be simpler to modify the string, but we don't; just to be nice
+   * to caller.
+   * We need to know how many digits we have, so we can allocate space for
+   * the digits' value.
+   */
+
+  char *p;
+  char c;
+  int seen_significant_digit;
+
+#ifdef ASSUME_DECIMAL_MARK_IS_DOT
+  assert (string_of_decimal_marks[0] == '.'
+	  && string_of_decimal_marks[1] == 0);
+#define IS_DECIMAL_MARK(c)	((c) == '.')
+#else
+#define IS_DECIMAL_MARK(c)	(0 != strchr (string_of_decimal_marks, (c)))
+#endif
+
+  first_digit = *address_of_string_pointer;
+  c = *first_digit;
+
+  if (c == '-' || c == '+')
+    {
+      digits_sign_char = c;
+      first_digit++;
+    }
+  else
+    digits_sign_char = '+';
+
+  switch (first_digit[0])
+    {
+    case 'n':
+    case 'N':
+      if (!strncasecmp ("nan", first_digit, 3))
+	{
+	  address_of_generic_floating_point_number->sign = 0;
+	  address_of_generic_floating_point_number->exponent = 0;
+	  address_of_generic_floating_point_number->leader =
+	    address_of_generic_floating_point_number->low;
+	  *address_of_string_pointer = first_digit + 3;
+	  return 0;
+	}
+      break;
+
+    case 'i':
+    case 'I':
+      if (!strncasecmp ("inf", first_digit, 3))
+	{
+	  address_of_generic_floating_point_number->sign =
+	    digits_sign_char == '+' ? 'P' : 'N';
+	  address_of_generic_floating_point_number->exponent = 0;
+	  address_of_generic_floating_point_number->leader =
+	    address_of_generic_floating_point_number->low;
+
+	  first_digit += 3;
+	  if (!strncasecmp ("inity", first_digit, 5))
+	    first_digit += 5;
+
+	  *address_of_string_pointer = first_digit;
+
+	  return 0;
+	}
+      break;
+    }
+
+  number_of_digits_before_decimal = 0;
+  number_of_digits_after_decimal = 0;
+  decimal_exponent = 0;
+  seen_significant_digit = 0;
+  for (p = first_digit;
+       (((c = *p) != '\0')
+	&& (!c || !IS_DECIMAL_MARK (c))
+	&& (!c || !strchr (string_of_decimal_exponent_marks, c)));
+       p++)
+    {
+      if (isdigit ((unsigned char) c))
+	{
+	  if (seen_significant_digit || c > '0')
+	    {
+	      ++number_of_digits_before_decimal;
+	      seen_significant_digit = 1;
+	    }
+	  else
+	    {
+	      first_digit++;
+	    }
+	}
+      else
+	{
+	  break;		/* p -> char after pre-decimal digits. */
+	}
+    }				/* For each digit before decimal mark. */
+
+#ifndef OLD_FLOAT_READS
+  /* Ignore trailing 0's after the decimal point.  The original code here
+   * (ifdef'd out) does not do this, and numbers like
+   *	4.29496729600000000000e+09	(2**31)
+   * come out inexact for some reason related to length of the digit
+   * string.
+   */
+  if (c && IS_DECIMAL_MARK (c))
+    {
+      unsigned int zeros = 0;	/* Length of current string of zeros */
+
+      for (p++; (c = *p) && isdigit ((unsigned char) c); p++)
+	{
+	  if (c == '0')
+	    {
+	      zeros++;
+	    }
+	  else
+	    {
+	      number_of_digits_after_decimal += 1 + zeros;
+	      zeros = 0;
+	    }
+	}
+    }
+#else
+  if (c && IS_DECIMAL_MARK (c))
+    {
+      for (p++;
+	   (((c = *p) != '\0')
+	    && (!c || !strchr (string_of_decimal_exponent_marks, c)));
+	   p++)
+	{
+	  if (isdigit (c))
+	    {
+	      /* This may be retracted below. */
+	      number_of_digits_after_decimal++;
+
+	      if ( /* seen_significant_digit || */ c > '0')
+		{
+		  seen_significant_digit = TRUE;
+		}
+	    }
+	  else
+	    {
+	      if (!seen_significant_digit)
+		{
+		  number_of_digits_after_decimal = 0;
+		}
+	      break;
+	    }
+	}			/* For each digit after decimal mark. */
+    }
+
+  while (number_of_digits_after_decimal
+	 && first_digit[number_of_digits_before_decimal
+			+ number_of_digits_after_decimal] == '0')
+    --number_of_digits_after_decimal;
+#endif
+
+  if (flag_m68k_mri)
+    {
+      while (c == '_')
+	c = *++p;
+    }
+  if (c && strchr (string_of_decimal_exponent_marks, c))
+    {
+      char digits_exponent_sign_char;
+
+      c = *++p;
+      if (flag_m68k_mri)
+	{
+	  while (c == '_')
+	    c = *++p;
+	}
+      if (c && strchr ("+-", c))
+	{
+	  digits_exponent_sign_char = c;
+	  c = *++p;
+	}
+      else
+	{
+	  digits_exponent_sign_char = '+';
+	}
+
+      for (; (c); c = *++p)
+	{
+	  if (isdigit ((unsigned char) c))
+	    {
+	      decimal_exponent = decimal_exponent * 10 + c - '0';
+	      /*
+	       * BUG! If we overflow here, we lose!
+	       */
+	    }
+	  else
+	    {
+	      break;
+	    }
+	}
+
+      if (digits_exponent_sign_char == '-')
+	{
+	  decimal_exponent = -decimal_exponent;
+	}
+    }
+
+  *address_of_string_pointer = p;
+
+
+
+  number_of_digits_available =
+    number_of_digits_before_decimal + number_of_digits_after_decimal;
+  return_value = 0;
+  if (number_of_digits_available == 0)
+    {
+      address_of_generic_floating_point_number->exponent = 0;	/* Not strictly necessary */
+      address_of_generic_floating_point_number->leader
+	= -1 + address_of_generic_floating_point_number->low;
+      address_of_generic_floating_point_number->sign = digits_sign_char;
+      /* We have just concocted (+/-)0.0E0 */
+
+    }
+  else
+    {
+      int count;		/* Number of useful digits left to scan. */
+
+      LITTLENUM_TYPE *digits_binary_low;
+      unsigned int precision;
+      unsigned int maximum_useful_digits;
+      unsigned int number_of_digits_to_use;
+      unsigned int more_than_enough_bits_for_digits;
+      unsigned int more_than_enough_littlenums_for_digits;
+      unsigned int size_of_digits_in_littlenums;
+      unsigned int size_of_digits_in_chars;
+      FLONUM_TYPE power_of_10_flonum;
+      FLONUM_TYPE digits_flonum;
+
+      precision = (address_of_generic_floating_point_number->high
+		   - address_of_generic_floating_point_number->low
+		   + 1);	/* Number of destination littlenums. */
+
+      /* Includes guard bits (two littlenums worth) */
+#if 0 /* The integer version below is very close, and it doesn't
+	 require floating point support (which is currently buggy on
+	 the Alpha).  */
+      maximum_useful_digits = (((double) (precision - 2))
+			       * ((double) (LITTLENUM_NUMBER_OF_BITS))
+			       / (LOG_TO_BASE_2_OF_10))
+	+ 2;			/* 2 :: guard digits. */
+#else
+      maximum_useful_digits = (((precision - 2))
+			       * ( (LITTLENUM_NUMBER_OF_BITS))
+			       * 1000000 / 3321928)
+	+ 2;			/* 2 :: guard digits. */
+#endif
+
+      if (number_of_digits_available > maximum_useful_digits)
+	{
+	  number_of_digits_to_use = maximum_useful_digits;
+	}
+      else
+	{
+	  number_of_digits_to_use = number_of_digits_available;
+	}
+
+      /* Cast these to SIGNED LONG first, otherwise, on systems with
+	 LONG wider than INT (such as Alpha OSF/1), unsignedness may
+	 cause unexpected results.  */
+      decimal_exponent += ((long) number_of_digits_before_decimal
+			   - (long) number_of_digits_to_use);
+
+#if 0
+      more_than_enough_bits_for_digits
+	= ((((double) number_of_digits_to_use) * LOG_TO_BASE_2_OF_10) + 1);
+#else
+      more_than_enough_bits_for_digits
+	= (number_of_digits_to_use * 3321928 / 1000000 + 1);
+#endif
+
+      more_than_enough_littlenums_for_digits
+	= (more_than_enough_bits_for_digits
+	   / LITTLENUM_NUMBER_OF_BITS)
+	+ 2;
+
+      /* Compute (digits) part. In "12.34E56" this is the "1234" part.
+	 Arithmetic is exact here. If no digits are supplied then this
+	 part is a 0 valued binary integer.  Allocate room to build up
+	 the binary number as littlenums.  We want this memory to
+	 disappear when we leave this function.  Assume no alignment
+	 problems => (room for n objects) == n * (room for 1
+	 object).  */
+
+      size_of_digits_in_littlenums = more_than_enough_littlenums_for_digits;
+      size_of_digits_in_chars = size_of_digits_in_littlenums
+	* sizeof (LITTLENUM_TYPE);
+
+      digits_binary_low = (LITTLENUM_TYPE *)
+	alloca (size_of_digits_in_chars);
+
+      memset ((char *) digits_binary_low, '\0', size_of_digits_in_chars);
+
+      /* Digits_binary_low[] is allocated and zeroed. */
+
+      /*
+       * Parse the decimal digits as if * digits_low was in the units position.
+       * Emit a binary number into digits_binary_low[].
+       *
+       * Use a large-precision version of:
+       * (((1st-digit) * 10 + 2nd-digit) * 10 + 3rd-digit ...) * 10 + last-digit
+       */
+
+      for (p = first_digit, count = number_of_digits_to_use; count; p++, --count)
+	{
+	  c = *p;
+	  if (isdigit ((unsigned char) c))
+	    {
+	      /*
+	       * Multiply by 10. Assume can never overflow.
+	       * Add this digit to digits_binary_low[].
+	       */
+
+	      long carry;
+	      LITTLENUM_TYPE *littlenum_pointer;
+	      LITTLENUM_TYPE *littlenum_limit;
+
+	      littlenum_limit = digits_binary_low
+		+ more_than_enough_littlenums_for_digits
+		- 1;
+
+	      carry = c - '0';	/* char -> binary */
+
+	      for (littlenum_pointer = digits_binary_low;
+		   littlenum_pointer <= littlenum_limit;
+		   littlenum_pointer++)
+		{
+		  long work;
+
+		  work = carry + 10 * (long) (*littlenum_pointer);
+		  *littlenum_pointer = work & LITTLENUM_MASK;
+		  carry = work >> LITTLENUM_NUMBER_OF_BITS;
+		}
+
+	      if (carry != 0)
+		{
+		  /*
+		   * We have a GROSS internal error.
+		   * This should never happen.
+		   */
+		  as_fatal (_("failed sanity check."));
+		}
+	    }
+	  else
+	    {
+	      ++count;		/* '.' doesn't alter digits used count. */
+	    }
+	}
+
+
+      /*
+       * Digits_binary_low[] properly encodes the value of the digits.
+       * Forget about any high-order littlenums that are 0.
+       */
+      while (digits_binary_low[size_of_digits_in_littlenums - 1] == 0
+	     && size_of_digits_in_littlenums >= 2)
+	size_of_digits_in_littlenums--;
+
+      digits_flonum.low = digits_binary_low;
+      digits_flonum.high = digits_binary_low + size_of_digits_in_littlenums - 1;
+      digits_flonum.leader = digits_flonum.high;
+      digits_flonum.exponent = 0;
+      /*
+       * The value of digits_flonum . sign should not be important.
+       * We have already decided the output's sign.
+       * We trust that the sign won't influence the other parts of the number!
+       * So we give it a value for these reasons:
+       * (1) courtesy to humans reading/debugging
+       *     these numbers so they don't get excited about strange values
+       * (2) in future there may be more meaning attached to sign,
+       *     and what was
+       *     harmless noise may become disruptive, ill-conditioned (or worse)
+       *     input.
+       */
+      digits_flonum.sign = '+';
+
+      {
+	/*
+	 * Compute the mantssa (& exponent) of the power of 10.
+	 * If sucessful, then multiply the power of 10 by the digits
+	 * giving return_binary_mantissa and return_binary_exponent.
+	 */
+
+	LITTLENUM_TYPE *power_binary_low;
+	int decimal_exponent_is_negative;
+	/* This refers to the "-56" in "12.34E-56". */
+	/* FALSE: decimal_exponent is positive (or 0) */
+	/* TRUE:  decimal_exponent is negative */
+	FLONUM_TYPE temporary_flonum;
+	LITTLENUM_TYPE *temporary_binary_low;
+	unsigned int size_of_power_in_littlenums;
+	unsigned int size_of_power_in_chars;
+
+	size_of_power_in_littlenums = precision;
+	/* Precision has a built-in fudge factor so we get a few guard bits. */
+
+	decimal_exponent_is_negative = decimal_exponent < 0;
+	if (decimal_exponent_is_negative)
+	  {
+	    decimal_exponent = -decimal_exponent;
+	  }
+
+	/* From now on: the decimal exponent is > 0. Its sign is separate. */
+
+	size_of_power_in_chars = size_of_power_in_littlenums
+	  * sizeof (LITTLENUM_TYPE) + 2;
+
+	power_binary_low = (LITTLENUM_TYPE *) alloca (size_of_power_in_chars);
+	temporary_binary_low = (LITTLENUM_TYPE *) alloca (size_of_power_in_chars);
+	memset ((char *) power_binary_low, '\0', size_of_power_in_chars);
+	*power_binary_low = 1;
+	power_of_10_flonum.exponent = 0;
+	power_of_10_flonum.low = power_binary_low;
+	power_of_10_flonum.leader = power_binary_low;
+	power_of_10_flonum.high = power_binary_low + size_of_power_in_littlenums - 1;
+	power_of_10_flonum.sign = '+';
+	temporary_flonum.low = temporary_binary_low;
+	temporary_flonum.high = temporary_binary_low + size_of_power_in_littlenums - 1;
+	/*
+	 * (power) == 1.
+	 * Space for temporary_flonum allocated.
+	 */
+
+	/*
+	 * ...
+	 *
+	 * WHILE	more bits
+	 * DO	find next bit (with place value)
+	 *	multiply into power mantissa
+	 * OD
+	 */
+	{
+	  int place_number_limit;
+	  /* Any 10^(2^n) whose "n" exceeds this */
+	  /* value will fall off the end of */
+	  /* flonum_XXXX_powers_of_ten[]. */
+	  int place_number;
+	  const FLONUM_TYPE *multiplicand;	/* -> 10^(2^n) */
+
+	  place_number_limit = table_size_of_flonum_powers_of_ten;
+
+	  multiplicand = (decimal_exponent_is_negative
+			  ? flonum_negative_powers_of_ten
+			  : flonum_positive_powers_of_ten);
+
+	  for (place_number = 1;/* Place value of this bit of exponent. */
+	       decimal_exponent;/* Quit when no more 1 bits in exponent. */
+	       decimal_exponent >>= 1, place_number++)
+	    {
+	      if (decimal_exponent & 1)
+		{
+		  if (place_number > place_number_limit)
+		    {
+		      /* The decimal exponent has a magnitude so great
+			 that our tables can't help us fragment it.
+			 Although this routine is in error because it
+			 can't imagine a number that big, signal an
+			 error as if it is the user's fault for
+			 presenting such a big number.  */
+		      return_value = ERROR_EXPONENT_OVERFLOW;
+		      /* quit out of loop gracefully */
+		      decimal_exponent = 0;
+		    }
+		  else
+		    {
+#ifdef TRACE
+		      printf ("before multiply, place_number = %d., power_of_10_flonum:\n",
+			      place_number);
+
+		      flonum_print (&power_of_10_flonum);
+		      (void) putchar ('\n');
+#endif
+#ifdef TRACE
+		      printf ("multiplier:\n");
+		      flonum_print (multiplicand + place_number);
+		      (void) putchar ('\n');
+#endif
+		      flonum_multip (multiplicand + place_number,
+				     &power_of_10_flonum, &temporary_flonum);
+#ifdef TRACE
+		      printf ("after multiply:\n");
+		      flonum_print (&temporary_flonum);
+		      (void) putchar ('\n');
+#endif
+		      flonum_copy (&temporary_flonum, &power_of_10_flonum);
+#ifdef TRACE
+		      printf ("after copy:\n");
+		      flonum_print (&power_of_10_flonum);
+		      (void) putchar ('\n');
+#endif
+		    } /* If this bit of decimal_exponent was computable.*/
+		} /* If this bit of decimal_exponent was set. */
+	    } /* For each bit of binary representation of exponent */
+#ifdef TRACE
+	  printf ("after computing power_of_10_flonum:\n");
+	  flonum_print (&power_of_10_flonum);
+	  (void) putchar ('\n');
+#endif
+	}
+
+      }
+
+      /*
+       * power_of_10_flonum is power of ten in binary (mantissa) , (exponent).
+       * It may be the number 1, in which case we don't NEED to multiply.
+       *
+       * Multiply (decimal digits) by power_of_10_flonum.
+       */
+
+      flonum_multip (&power_of_10_flonum, &digits_flonum, address_of_generic_floating_point_number);
+      /* Assert sign of the number we made is '+'. */
+      address_of_generic_floating_point_number->sign = digits_sign_char;
+
+    }
+  return return_value;
+}
+
+#ifdef TRACE
+static void
+flonum_print (f)
+     const FLONUM_TYPE *f;
+{
+  LITTLENUM_TYPE *lp;
+  char littlenum_format[10];
+  sprintf (littlenum_format, " %%0%dx", sizeof (LITTLENUM_TYPE) * 2);
+#define print_littlenum(LP)	(printf (littlenum_format, LP))
+  printf ("flonum @%p %c e%ld", f, f->sign, f->exponent);
+  if (f->low < f->high)
+    for (lp = f->high; lp >= f->low; lp--)
+      print_littlenum (*lp);
+  else
+    for (lp = f->low; lp <= f->high; lp++)
+      print_littlenum (*lp);
+  printf ("\n");
+  fflush (stdout);
+}
+#endif
+
+/* end of atof_generic.c */