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Diffstat (limited to 'contrib/binutils/libiberty/floatformat.c')
| -rw-r--r-- | contrib/binutils/libiberty/floatformat.c | 620 |
1 files changed, 0 insertions, 620 deletions
diff --git a/contrib/binutils/libiberty/floatformat.c b/contrib/binutils/libiberty/floatformat.c deleted file mode 100644 index a0f65354e482..000000000000 --- a/contrib/binutils/libiberty/floatformat.c +++ /dev/null @@ -1,620 +0,0 @@ -/* IEEE floating point support routines, for GDB, the GNU Debugger. - Copyright (C) 1991, 1994, 1999, 2000, 2003 Free Software Foundation, Inc. - -This file is part of GDB. - -This program 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 of the License, or -(at your option) any later version. - -This program 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 this program; if not, write to the Free Software -Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ - -/* This is needed to pick up the NAN macro on some systems. */ -#define _GNU_SOURCE - -#ifdef HAVE_CONFIG_H -#include "config.h" -#endif - -#include <math.h> - -#ifdef HAVE_STRING_H -#include <string.h> -#endif - -#include "ansidecl.h" -#include "libiberty.h" -#include "floatformat.h" - -#ifndef INFINITY -#ifdef HUGE_VAL -#define INFINITY HUGE_VAL -#else -#define INFINITY (1.0 / 0.0) -#endif -#endif - -#ifndef NAN -#define NAN (0.0 / 0.0) -#endif - -static unsigned long get_field PARAMS ((const unsigned char *, - enum floatformat_byteorders, - unsigned int, - unsigned int, - unsigned int)); -static int floatformat_always_valid PARAMS ((const struct floatformat *fmt, - const char *from)); - -static int -floatformat_always_valid (fmt, from) - const struct floatformat *fmt ATTRIBUTE_UNUSED; - const char *from ATTRIBUTE_UNUSED; -{ - return 1; -} - -/* The odds that CHAR_BIT will be anything but 8 are low enough that I'm not - going to bother with trying to muck around with whether it is defined in - a system header, what we do if not, etc. */ -#define FLOATFORMAT_CHAR_BIT 8 - -/* floatformats for IEEE single and double, big and little endian. */ -const struct floatformat floatformat_ieee_single_big = -{ - floatformat_big, 32, 0, 1, 8, 127, 255, 9, 23, - floatformat_intbit_no, - "floatformat_ieee_single_big", - floatformat_always_valid -}; -const struct floatformat floatformat_ieee_single_little = -{ - floatformat_little, 32, 0, 1, 8, 127, 255, 9, 23, - floatformat_intbit_no, - "floatformat_ieee_single_little", - floatformat_always_valid -}; -const struct floatformat floatformat_ieee_double_big = -{ - floatformat_big, 64, 0, 1, 11, 1023, 2047, 12, 52, - floatformat_intbit_no, - "floatformat_ieee_double_big", - floatformat_always_valid -}; -const struct floatformat floatformat_ieee_double_little = -{ - floatformat_little, 64, 0, 1, 11, 1023, 2047, 12, 52, - floatformat_intbit_no, - "floatformat_ieee_double_little", - floatformat_always_valid -}; - -/* floatformat for IEEE double, little endian byte order, with big endian word - ordering, as on the ARM. */ - -const struct floatformat floatformat_ieee_double_littlebyte_bigword = -{ - floatformat_littlebyte_bigword, 64, 0, 1, 11, 1023, 2047, 12, 52, - floatformat_intbit_no, - "floatformat_ieee_double_littlebyte_bigword", - floatformat_always_valid -}; - -static int floatformat_i387_ext_is_valid PARAMS ((const struct floatformat *fmt, const char *from)); - -static int -floatformat_i387_ext_is_valid (fmt, from) - const struct floatformat *fmt; - const char *from; -{ - /* In the i387 double-extended format, if the exponent is all ones, - then the integer bit must be set. If the exponent is neither 0 - nor ~0, the intbit must also be set. Only if the exponent is - zero can it be zero, and then it must be zero. */ - unsigned long exponent, int_bit; - const unsigned char *ufrom = (const unsigned char *) from; - - exponent = get_field (ufrom, fmt->byteorder, fmt->totalsize, - fmt->exp_start, fmt->exp_len); - int_bit = get_field (ufrom, fmt->byteorder, fmt->totalsize, - fmt->man_start, 1); - - if ((exponent == 0) != (int_bit == 0)) - return 0; - else - return 1; -} - -const struct floatformat floatformat_i387_ext = -{ - floatformat_little, 80, 0, 1, 15, 0x3fff, 0x7fff, 16, 64, - floatformat_intbit_yes, - "floatformat_i387_ext", - floatformat_i387_ext_is_valid -}; -const struct floatformat floatformat_m68881_ext = -{ - /* Note that the bits from 16 to 31 are unused. */ - floatformat_big, 96, 0, 1, 15, 0x3fff, 0x7fff, 32, 64, - floatformat_intbit_yes, - "floatformat_m68881_ext", - floatformat_always_valid -}; -const struct floatformat floatformat_i960_ext = -{ - /* Note that the bits from 0 to 15 are unused. */ - floatformat_little, 96, 16, 17, 15, 0x3fff, 0x7fff, 32, 64, - floatformat_intbit_yes, - "floatformat_i960_ext", - floatformat_always_valid -}; -const struct floatformat floatformat_m88110_ext = -{ - floatformat_big, 80, 0, 1, 15, 0x3fff, 0x7fff, 16, 64, - floatformat_intbit_yes, - "floatformat_m88110_ext", - floatformat_always_valid -}; -const struct floatformat floatformat_m88110_harris_ext = -{ - /* Harris uses raw format 128 bytes long, but the number is just an ieee - double, and the last 64 bits are wasted. */ - floatformat_big,128, 0, 1, 11, 0x3ff, 0x7ff, 12, 52, - floatformat_intbit_no, - "floatformat_m88110_ext_harris", - floatformat_always_valid -}; -const struct floatformat floatformat_arm_ext_big = -{ - /* Bits 1 to 16 are unused. */ - floatformat_big, 96, 0, 17, 15, 0x3fff, 0x7fff, 32, 64, - floatformat_intbit_yes, - "floatformat_arm_ext_big", - floatformat_always_valid -}; -const struct floatformat floatformat_arm_ext_littlebyte_bigword = -{ - /* Bits 1 to 16 are unused. */ - floatformat_littlebyte_bigword, 96, 0, 17, 15, 0x3fff, 0x7fff, 32, 64, - floatformat_intbit_yes, - "floatformat_arm_ext_littlebyte_bigword", - floatformat_always_valid -}; -const struct floatformat floatformat_ia64_spill_big = -{ - floatformat_big, 128, 0, 1, 17, 65535, 0x1ffff, 18, 64, - floatformat_intbit_yes, - "floatformat_ia64_spill_big", - floatformat_always_valid -}; -const struct floatformat floatformat_ia64_spill_little = -{ - floatformat_little, 128, 0, 1, 17, 65535, 0x1ffff, 18, 64, - floatformat_intbit_yes, - "floatformat_ia64_spill_little", - floatformat_always_valid -}; -const struct floatformat floatformat_ia64_quad_big = -{ - floatformat_big, 128, 0, 1, 15, 16383, 0x7fff, 16, 112, - floatformat_intbit_no, - "floatformat_ia64_quad_big", - floatformat_always_valid -}; -const struct floatformat floatformat_ia64_quad_little = -{ - floatformat_little, 128, 0, 1, 15, 16383, 0x7fff, 16, 112, - floatformat_intbit_no, - "floatformat_ia64_quad_little", - floatformat_always_valid -}; - -/* Extract a field which starts at START and is LEN bits long. DATA and - TOTAL_LEN are the thing we are extracting it from, in byteorder ORDER. */ -static unsigned long -get_field (data, order, total_len, start, len) - const unsigned char *data; - enum floatformat_byteorders order; - unsigned int total_len; - unsigned int start; - unsigned int len; -{ - unsigned long result; - unsigned int cur_byte; - int cur_bitshift; - - /* Start at the least significant part of the field. */ - cur_byte = (start + len) / FLOATFORMAT_CHAR_BIT; - if (order == floatformat_little) - cur_byte = (total_len / FLOATFORMAT_CHAR_BIT) - cur_byte - 1; - cur_bitshift = - ((start + len) % FLOATFORMAT_CHAR_BIT) - FLOATFORMAT_CHAR_BIT; - result = *(data + cur_byte) >> (-cur_bitshift); - cur_bitshift += FLOATFORMAT_CHAR_BIT; - if (order == floatformat_little) - ++cur_byte; - else - --cur_byte; - - /* Move towards the most significant part of the field. */ - while ((unsigned int) cur_bitshift < len) - { - if (len - cur_bitshift < FLOATFORMAT_CHAR_BIT) - /* This is the last byte; zero out the bits which are not part of - this field. */ - result |= - (*(data + cur_byte) & ((1 << (len - cur_bitshift)) - 1)) - << cur_bitshift; - else - result |= *(data + cur_byte) << cur_bitshift; - cur_bitshift += FLOATFORMAT_CHAR_BIT; - if (order == floatformat_little) - ++cur_byte; - else - --cur_byte; - } - return result; -} - -#ifndef min -#define min(a, b) ((a) < (b) ? (a) : (b)) -#endif - -/* Convert from FMT to a double. - FROM is the address of the extended float. - Store the double in *TO. */ - -void -floatformat_to_double (fmt, from, to) - const struct floatformat *fmt; - const char *from; - double *to; -{ - const unsigned char *ufrom = (const unsigned char *)from; - double dto; - long exponent; - unsigned long mant; - unsigned int mant_bits, mant_off; - int mant_bits_left; - int special_exponent; /* It's a NaN, denorm or zero */ - - exponent = get_field (ufrom, fmt->byteorder, fmt->totalsize, - fmt->exp_start, fmt->exp_len); - - /* If the exponent indicates a NaN, we don't have information to - decide what to do. So we handle it like IEEE, except that we - don't try to preserve the type of NaN. FIXME. */ - if ((unsigned long) exponent == fmt->exp_nan) - { - int nan; - - mant_off = fmt->man_start; - mant_bits_left = fmt->man_len; - nan = 0; - while (mant_bits_left > 0) - { - mant_bits = min (mant_bits_left, 32); - - if (get_field (ufrom, fmt->byteorder, fmt->totalsize, - mant_off, mant_bits) != 0) - { - /* This is a NaN. */ - nan = 1; - break; - } - - mant_off += mant_bits; - mant_bits_left -= mant_bits; - } - - if (nan) - dto = NAN; - else - dto = INFINITY; - - if (get_field (ufrom, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1)) - dto = -dto; - - *to = dto; - - return; - } - - mant_bits_left = fmt->man_len; - mant_off = fmt->man_start; - dto = 0.0; - - special_exponent = exponent == 0 || (unsigned long) exponent == fmt->exp_nan; - - /* Don't bias zero's, denorms or NaNs. */ - if (!special_exponent) - exponent -= fmt->exp_bias; - - /* Build the result algebraically. Might go infinite, underflow, etc; - who cares. */ - - /* If this format uses a hidden bit, explicitly add it in now. Otherwise, - increment the exponent by one to account for the integer bit. */ - - if (!special_exponent) - { - if (fmt->intbit == floatformat_intbit_no) - dto = ldexp (1.0, exponent); - else - exponent++; - } - - while (mant_bits_left > 0) - { - mant_bits = min (mant_bits_left, 32); - - mant = get_field (ufrom, fmt->byteorder, fmt->totalsize, - mant_off, mant_bits); - - /* Handle denormalized numbers. FIXME: What should we do for - non-IEEE formats? */ - if (exponent == 0 && mant != 0) - dto += ldexp ((double)mant, - (- fmt->exp_bias - - mant_bits - - (mant_off - fmt->man_start) - + 1)); - else - dto += ldexp ((double)mant, exponent - mant_bits); - if (exponent != 0) - exponent -= mant_bits; - mant_off += mant_bits; - mant_bits_left -= mant_bits; - } - - /* Negate it if negative. */ - if (get_field (ufrom, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1)) - dto = -dto; - *to = dto; -} - -static void put_field PARAMS ((unsigned char *, enum floatformat_byteorders, - unsigned int, - unsigned int, - unsigned int, - unsigned long)); - -/* Set a field which starts at START and is LEN bits long. DATA and - TOTAL_LEN are the thing we are extracting it from, in byteorder ORDER. */ -static void -put_field (data, order, total_len, start, len, stuff_to_put) - unsigned char *data; - enum floatformat_byteorders order; - unsigned int total_len; - unsigned int start; - unsigned int len; - unsigned long stuff_to_put; -{ - unsigned int cur_byte; - int cur_bitshift; - - /* Start at the least significant part of the field. */ - cur_byte = (start + len) / FLOATFORMAT_CHAR_BIT; - if (order == floatformat_little) - cur_byte = (total_len / FLOATFORMAT_CHAR_BIT) - cur_byte - 1; - cur_bitshift = - ((start + len) % FLOATFORMAT_CHAR_BIT) - FLOATFORMAT_CHAR_BIT; - *(data + cur_byte) &= - ~(((1 << ((start + len) % FLOATFORMAT_CHAR_BIT)) - 1) << (-cur_bitshift)); - *(data + cur_byte) |= - (stuff_to_put & ((1 << FLOATFORMAT_CHAR_BIT) - 1)) << (-cur_bitshift); - cur_bitshift += FLOATFORMAT_CHAR_BIT; - if (order == floatformat_little) - ++cur_byte; - else - --cur_byte; - - /* Move towards the most significant part of the field. */ - while ((unsigned int) cur_bitshift < len) - { - if (len - cur_bitshift < FLOATFORMAT_CHAR_BIT) - { - /* This is the last byte. */ - *(data + cur_byte) &= - ~((1 << (len - cur_bitshift)) - 1); - *(data + cur_byte) |= (stuff_to_put >> cur_bitshift); - } - else - *(data + cur_byte) = ((stuff_to_put >> cur_bitshift) - & ((1 << FLOATFORMAT_CHAR_BIT) - 1)); - cur_bitshift += FLOATFORMAT_CHAR_BIT; - if (order == floatformat_little) - ++cur_byte; - else - --cur_byte; - } -} - -/* The converse: convert the double *FROM to an extended float - and store where TO points. Neither FROM nor TO have any alignment - restrictions. */ - -void -floatformat_from_double (fmt, from, to) - const struct floatformat *fmt; - const double *from; - char *to; -{ - double dfrom; - int exponent; - double mant; - unsigned int mant_bits, mant_off; - int mant_bits_left; - unsigned char *uto = (unsigned char *)to; - - dfrom = *from; - memset (uto, 0, fmt->totalsize / FLOATFORMAT_CHAR_BIT); - - /* If negative, set the sign bit. */ - if (dfrom < 0) - { - put_field (uto, fmt->byteorder, fmt->totalsize, fmt->sign_start, 1, 1); - dfrom = -dfrom; - } - - if (dfrom == 0) - { - /* 0.0. */ - return; - } - - if (dfrom != dfrom) - { - /* NaN. */ - put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start, - fmt->exp_len, fmt->exp_nan); - /* Be sure it's not infinity, but NaN value is irrelevant. */ - put_field (uto, fmt->byteorder, fmt->totalsize, fmt->man_start, - 32, 1); - return; - } - - if (dfrom + dfrom == dfrom) - { - /* This can only happen for an infinite value (or zero, which we - already handled above). */ - put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start, - fmt->exp_len, fmt->exp_nan); - return; - } - - mant = frexp (dfrom, &exponent); - if (exponent + fmt->exp_bias - 1 > 0) - put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start, - fmt->exp_len, exponent + fmt->exp_bias - 1); - else - { - /* Handle a denormalized number. FIXME: What should we do for - non-IEEE formats? */ - put_field (uto, fmt->byteorder, fmt->totalsize, fmt->exp_start, - fmt->exp_len, 0); - mant = ldexp (mant, exponent + fmt->exp_bias - 1); - } - - mant_bits_left = fmt->man_len; - mant_off = fmt->man_start; - while (mant_bits_left > 0) - { - unsigned long mant_long; - mant_bits = mant_bits_left < 32 ? mant_bits_left : 32; - - mant *= 4294967296.0; - mant_long = (unsigned long)mant; - mant -= mant_long; - - /* If the integer bit is implicit, and we are not creating a - denormalized number, then we need to discard it. */ - if ((unsigned int) mant_bits_left == fmt->man_len - && fmt->intbit == floatformat_intbit_no - && exponent + fmt->exp_bias - 1 > 0) - { - mant_long &= 0x7fffffff; - mant_bits -= 1; - } - else if (mant_bits < 32) - { - /* The bits we want are in the most significant MANT_BITS bits of - mant_long. Move them to the least significant. */ - mant_long >>= 32 - mant_bits; - } - - put_field (uto, fmt->byteorder, fmt->totalsize, - mant_off, mant_bits, mant_long); - mant_off += mant_bits; - mant_bits_left -= mant_bits; - } -} - -/* Return non-zero iff the data at FROM is a valid number in format FMT. */ - -int -floatformat_is_valid (fmt, from) - const struct floatformat *fmt; - const char *from; -{ - return fmt->is_valid (fmt, from); -} - - -#ifdef IEEE_DEBUG - -#include <stdio.h> - -/* This is to be run on a host which uses IEEE floating point. */ - -void -ieee_test (n) - double n; -{ - double result; - - floatformat_to_double (&floatformat_ieee_double_little, (char *) &n, - &result); - if ((n != result && (! isnan (n) || ! isnan (result))) - || (n < 0 && result >= 0) - || (n >= 0 && result < 0)) - printf ("Differ(to): %.20g -> %.20g\n", n, result); - - floatformat_from_double (&floatformat_ieee_double_little, &n, - (char *) &result); - if ((n != result && (! isnan (n) || ! isnan (result))) - || (n < 0 && result >= 0) - || (n >= 0 && result < 0)) - printf ("Differ(from): %.20g -> %.20g\n", n, result); - -#if 0 - { - char exten[16]; - - floatformat_from_double (&floatformat_m68881_ext, &n, exten); - floatformat_to_double (&floatformat_m68881_ext, exten, &result); - if (n != result) - printf ("Differ(to+from): %.20g -> %.20g\n", n, result); - } -#endif - -#if IEEE_DEBUG > 1 - /* This is to be run on a host which uses 68881 format. */ - { - long double ex = *(long double *)exten; - if (ex != n) - printf ("Differ(from vs. extended): %.20g\n", n); - } -#endif -} - -int -main () -{ - ieee_test (0.0); - ieee_test (0.5); - ieee_test (256.0); - ieee_test (0.12345); - ieee_test (234235.78907234); - ieee_test (-512.0); - ieee_test (-0.004321); - ieee_test (1.2E-70); - ieee_test (1.2E-316); - ieee_test (4.9406564584124654E-324); - ieee_test (- 4.9406564584124654E-324); - ieee_test (- 0.0); - ieee_test (- INFINITY); - ieee_test (- NAN); - ieee_test (INFINITY); - ieee_test (NAN); - return 0; -} -#endif |