+++ /dev/null
-/* atof_ns32k.c - turn a Flonum into a ns32k floating point number
- Copyright (C) 1987 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 1, 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, 675 Mass Ave, Cambridge, MA 02139, USA. */
-
-/* this is atof-m68k.c hacked for ns32k */
-
-#include "as.h"
-
-extern FLONUM_TYPE generic_floating_point_number; /* Flonums returned here. */
-
-extern const char EXP_CHARS[];
-/* Precision in LittleNums. */
-#define MAX_PRECISION (4)
-#define F_PRECISION (2)
-#define D_PRECISION (4)
-
-/* Length in LittleNums of guard bits. */
-#define GUARD (2)
-
-int /* Number of chars in flonum type 'letter'. */
-atof_sizeof (letter)
- char letter;
-{
- int return_value;
-
- /*
- * Permitting uppercase letters is probably a bad idea.
- * Please use only lower-cased letters in case the upper-cased
- * ones become unsupported!
- */
- switch (letter)
- {
- case 'f':
- return_value = F_PRECISION;
- break;
-
- case 'd':
- return_value = D_PRECISION;
- break;
-
- default:
- return_value = 0;
- break;
- }
- return (return_value);
-}
-
-static unsigned long int mask[] =
-{
- 0x00000000,
- 0x00000001,
- 0x00000003,
- 0x00000007,
- 0x0000000f,
- 0x0000001f,
- 0x0000003f,
- 0x0000007f,
- 0x000000ff,
- 0x000001ff,
- 0x000003ff,
- 0x000007ff,
- 0x00000fff,
- 0x00001fff,
- 0x00003fff,
- 0x00007fff,
- 0x0000ffff,
- 0x0001ffff,
- 0x0003ffff,
- 0x0007ffff,
- 0x000fffff,
- 0x001fffff,
- 0x003fffff,
- 0x007fffff,
- 0x00ffffff,
- 0x01ffffff,
- 0x03ffffff,
- 0x07ffffff,
- 0x0fffffff,
- 0x1fffffff,
- 0x3fffffff,
- 0x7fffffff,
- 0xffffffff
-};
-\f
-static int bits_left_in_littlenum;
-static int littlenums_left;
-static LITTLENUM_TYPE *littlenum_pointer;
-
-static int
-next_bits (number_of_bits)
- int number_of_bits;
-{
- int return_value;
-
- if (!littlenums_left)
- return 0;
- if (number_of_bits >= bits_left_in_littlenum)
- {
- return_value = mask[bits_left_in_littlenum] & *littlenum_pointer;
- number_of_bits -= bits_left_in_littlenum;
- return_value <<= number_of_bits;
- if (littlenums_left)
- {
- bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS - number_of_bits;
- littlenum_pointer--;
- --littlenums_left;
- return_value |= (*littlenum_pointer >> bits_left_in_littlenum) & mask[number_of_bits];
- }
- }
- else
- {
- bits_left_in_littlenum -= number_of_bits;
- return_value = mask[number_of_bits] & (*littlenum_pointer >> bits_left_in_littlenum);
- }
- return (return_value);
-}
-
-static void
-make_invalid_floating_point_number (words)
- LITTLENUM_TYPE *words;
-{
- words[0] = ((unsigned) -1) >> 1; /* Zero the leftmost bit */
- words[1] = -1;
- words[2] = -1;
- words[3] = -1;
-}
-\f
-/***********************************************************************\
-* *
-* Warning: this returns 16-bit LITTLENUMs, because that is *
-* what the VAX thinks in. It is up to the caller to figure *
-* out any alignment problems and to conspire for the bytes/word *
-* to be emitted in the right order. Bigendians beware! *
-* *
-\***********************************************************************/
-
-char * /* Return pointer past text consumed. */
-atof_ns32k (str, what_kind, words)
- char *str; /* Text to convert to binary. */
- char what_kind; /* 'd', 'f', 'g', 'h' */
- LITTLENUM_TYPE *words; /* Build the binary here. */
-{
- FLONUM_TYPE f;
- LITTLENUM_TYPE bits[MAX_PRECISION + MAX_PRECISION + GUARD];
- /* Extra bits for zeroed low-order bits. */
- /* The 1st MAX_PRECISION are zeroed, */
- /* the last contain flonum bits. */
- char *return_value;
- int precision; /* Number of 16-bit words in the format. */
- long int exponent_bits;
-
- long int exponent_1;
- long int exponent_2;
- long int exponent_3;
- long int exponent_4;
- int exponent_skippage;
- LITTLENUM_TYPE word1;
- LITTLENUM_TYPE *lp;
-
- return_value = str;
- f.low = bits + MAX_PRECISION;
- f.high = NULL;
- f.leader = NULL;
- f.exponent = NULL;
- f.sign = '\0';
-
- /* Use more LittleNums than seems */
- /* necessary: the highest flonum may have */
- /* 15 leading 0 bits, so could be useless. */
-
- bzero (bits, sizeof (LITTLENUM_TYPE) * MAX_PRECISION);
-
- switch (what_kind)
- {
- case 'f':
- precision = F_PRECISION;
- exponent_bits = 8;
- break;
-
- case 'd':
- precision = D_PRECISION;
- exponent_bits = 11;
- break;
-
- default:
- make_invalid_floating_point_number (words);
- return NULL;
- }
-
- f.high = f.low + precision - 1 + GUARD;
-
- if (atof_generic (&return_value, ".", EXP_CHARS, &f))
- {
- as_warn ("Error converting floating point number (Exponent overflow?)");
- make_invalid_floating_point_number (words);
- return NULL;
- }
-
- if (f.low > f.leader)
- {
- /* 0.0e0 seen. */
- bzero (words, sizeof (LITTLENUM_TYPE) * precision);
- return return_value;
- }
-
- if (f.sign != '+' && f.sign != '-')
- {
- make_invalid_floating_point_number (words);
- return NULL;
- }
-
-
- /*
- * All vaxen floating_point formats (so far) have:
- * Bit 15 is sign bit.
- * Bits 14:n are excess-whatever exponent.
- * Bits n-1:0 (if any) are most significant bits of fraction.
- * Bits 15:0 of the next word are the next most significant bits.
- * And so on for each other word.
- *
- * So we need: number of bits of exponent, number of bits of
- * mantissa.
- */
- bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS;
- littlenum_pointer = f.leader;
- littlenums_left = 1 + f.leader - f.low;
- /* Seek (and forget) 1st significant bit */
- for (exponent_skippage = 0; !next_bits (1); exponent_skippage++)
- ;
- exponent_1 = f.exponent + f.leader + 1 - f.low;
- /* Radix LITTLENUM_RADIX, point just higher than f.leader. */
- exponent_2 = exponent_1 * LITTLENUM_NUMBER_OF_BITS;
- /* Radix 2. */
- exponent_3 = exponent_2 - exponent_skippage;
- /* Forget leading zeros, forget 1st bit. */
- exponent_4 = exponent_3 + ((1 << (exponent_bits - 1)) - 2);
- /* Offset exponent. */
-
- if (exponent_4 & ~mask[exponent_bits])
- {
- /*
- * Exponent overflow. Lose immediately.
- */
-
- /*
- * We leave return_value alone: admit we read the
- * number, but return a floating exception
- * because we can't encode the number.
- */
-
- as_warn ("Exponent overflow in floating-point number");
- make_invalid_floating_point_number (words);
- return return_value;
- }
- lp = words;
-
- /* Word 1. Sign, exponent and perhaps high bits. */
- /* Assume 2's complement integers. */
- word1 = ((exponent_4 & mask[exponent_bits]) << (15 - exponent_bits)) |
- ((f.sign == '+') ? 0 : 0x8000) | next_bits (15 - exponent_bits);
- *lp++ = word1;
-
- /* The rest of the words are just mantissa bits. */
- for (; lp < words + precision; lp++)
- *lp = next_bits (LITTLENUM_NUMBER_OF_BITS);
-
- if (next_bits (1))
- {
- unsigned long int carry;
- /*
- * Since the NEXT bit is a 1, round UP the mantissa.
- * The cunning design of these hidden-1 floats permits
- * us to let the mantissa overflow into the exponent, and
- * it 'does the right thing'. However, we lose if the
- * highest-order bit of the lowest-order word flips.
- * Is that clear?
- */
-
-
- /* #if (sizeof(carry)) < ((sizeof(bits[0]) * BITS_PER_CHAR) + 2)
- Please allow at least 1 more bit in carry than is in a LITTLENUM.
- We need that extra bit to hold a carry during a LITTLENUM carry
- propagation. Another extra bit (kept 0) will assure us that we
- don't get a sticky sign bit after shifting right, and that
- permits us to propagate the carry without any masking of bits.
-#endif */
- for (carry = 1, lp--; carry && (lp >= words); lp--)
- {
- carry = *lp + carry;
- *lp = carry;
- carry >>= LITTLENUM_NUMBER_OF_BITS;
- }
- if ((word1 ^ *words) & (1 << (LITTLENUM_NUMBER_OF_BITS - 1)))
- {
- /* We leave return_value alone: admit we read the
- * number, but return a floating exception
- * because we can't encode the number.
- */
- make_invalid_floating_point_number (words);
- return return_value;
- }
- }
- return (return_value);
-}
-
-/* This is really identical to atof_ns32k except for some details */
-
-gen_to_words (words, precision, exponent_bits)
- LITTLENUM_TYPE *words;
- long int exponent_bits;
-{
- int return_value = 0;
-
- long int exponent_1;
- long int exponent_2;
- long int exponent_3;
- long int exponent_4;
- int exponent_skippage;
- LITTLENUM_TYPE word1;
- LITTLENUM_TYPE *lp;
-
- if (generic_floating_point_number.low > generic_floating_point_number.leader)
- {
- /* 0.0e0 seen. */
- bzero (words, sizeof (LITTLENUM_TYPE) * precision);
- return return_value;
- }
-
- /*
- * All vaxen floating_point formats (so far) have:
- * Bit 15 is sign bit.
- * Bits 14:n are excess-whatever exponent.
- * Bits n-1:0 (if any) are most significant bits of fraction.
- * Bits 15:0 of the next word are the next most significant bits.
- * And so on for each other word.
- *
- * So we need: number of bits of exponent, number of bits of
- * mantissa.
- */
- bits_left_in_littlenum = LITTLENUM_NUMBER_OF_BITS;
- littlenum_pointer = generic_floating_point_number.leader;
- littlenums_left = 1 + generic_floating_point_number.leader - generic_floating_point_number.low;
- /* Seek (and forget) 1st significant bit */
- for (exponent_skippage = 0; !next_bits (1); exponent_skippage++)
- ;
- exponent_1 = generic_floating_point_number.exponent + generic_floating_point_number.leader + 1 -
- generic_floating_point_number.low;
- /* Radix LITTLENUM_RADIX, point just higher than generic_floating_point_number.leader. */
- exponent_2 = exponent_1 * LITTLENUM_NUMBER_OF_BITS;
- /* Radix 2. */
- exponent_3 = exponent_2 - exponent_skippage;
- /* Forget leading zeros, forget 1st bit. */
- exponent_4 = exponent_3 + ((1 << (exponent_bits - 1)) - 2);
- /* Offset exponent. */
-
- if (exponent_4 & ~mask[exponent_bits])
- {
- /*
- * Exponent overflow. Lose immediately.
- */
-
- /*
- * We leave return_value alone: admit we read the
- * number, but return a floating exception
- * because we can't encode the number.
- */
-
- make_invalid_floating_point_number (words);
- return return_value;
- }
- lp = words;
-
- /* Word 1. Sign, exponent and perhaps high bits. */
- /* Assume 2's complement integers. */
- word1 = ((exponent_4 & mask[exponent_bits]) << (15 - exponent_bits)) |
- ((generic_floating_point_number.sign == '+') ? 0 : 0x8000) | next_bits (15 - exponent_bits);
- *lp++ = word1;
-
- /* The rest of the words are just mantissa bits. */
- for (; lp < words + precision; lp++)
- *lp = next_bits (LITTLENUM_NUMBER_OF_BITS);
-
- if (next_bits (1))
- {
- unsigned long int carry;
- /*
- * Since the NEXT bit is a 1, round UP the mantissa.
- * The cunning design of these hidden-1 floats permits
- * us to let the mantissa overflow into the exponent, and
- * it 'does the right thing'. However, we lose if the
- * highest-order bit of the lowest-order word flips.
- * Is that clear?
- */
-
-
- /* #if (sizeof(carry)) < ((sizeof(bits[0]) * BITS_PER_CHAR) + 2)
- Please allow at least 1 more bit in carry than is in a LITTLENUM.
- We need that extra bit to hold a carry during a LITTLENUM carry
- propagation. Another extra bit (kept 0) will assure us that we
- don't get a sticky sign bit after shifting right, and that
- permits us to propagate the carry without any masking of bits.
-#endif */
- for (carry = 1, lp--; carry && (lp >= words); lp--)
- {
- carry = *lp + carry;
- *lp = carry;
- carry >>= LITTLENUM_NUMBER_OF_BITS;
- }
- if ((word1 ^ *words) & (1 << (LITTLENUM_NUMBER_OF_BITS - 1)))
- {
- /* We leave return_value alone: admit we read the
- * number, but return a floating exception
- * because we can't encode the number.
- */
- make_invalid_floating_point_number (words);
- return return_value;
- }
- }
- return (return_value);
-}
-
-/* This routine is a real kludge. Someone really should do it better, but
- I'm too lazy, and I don't understand this stuff all too well anyway
- (JF)
- */
-void
-int_to_gen (x)
- long x;
-{
- char buf[20];
- char *bufp;
-
- sprintf (buf, "%ld", x);
- bufp = &buf[0];
- if (atof_generic (&bufp, ".", EXP_CHARS, &generic_floating_point_number))
- as_warn ("Error converting number to floating point (Exponent overflow?)");
-}
projects / binutils-gdb.git / commitdiff