diff options
author | Joseph Myers <joseph@codesourcery.com> | 2007-11-08 00:08:48 +0000 |
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committer | Joseph Myers <joseph@codesourcery.com> | 2007-11-08 00:08:48 +0000 |
commit | b14d30e141e438bf7caebb1925569510eae049d7 (patch) | |
tree | 61e4f7993a702a3ec527bda64b5ccda54ca8ee7f /libiberty/floatformat.c | |
parent | 5d324c3ec4090c667b24441e3a5653f1dfd8e261 (diff) | |
download | gdb-b14d30e141e438bf7caebb1925569510eae049d7.zip gdb-b14d30e141e438bf7caebb1925569510eae049d7.tar.gz gdb-b14d30e141e438bf7caebb1925569510eae049d7.tar.bz2 |
include:
2007-11-07 Joseph Myers <joseph@codesourcery.com>
Daniel Jacobowitz <dan@codesourcery.com>
* floatformat.h (struct floatformat): Add split_half field.
(floatformat_ibm_long_double): New.
libiberty:
2007-11-07 Joseph Myers <joseph@codesourcery.com>
Daniel Jacobowitz <dan@codesourcery.com>
* floatformat.c (mant_bits_set): New.
(floatformat_to_double): Use it. Note no special handling of
split formats.
(floatformat_from_double): Note no special handing of split
formats.
(floatformat_ibm_long_double_is_valid,
floatformat_ibm_long_double): New.
(floatformat_ieee_single_big, floatformat_ieee_single_little,
floatformat_ieee_double_big, floatformat_ieee_double_little,
floatformat_ieee_double_littlebyte_bigword, floatformat_vax_f,
floatformat_vax_d, floatformat_vax_g, floatformat_i387_ext,
floatformat_m68881_ext, floatformat_i960_ext,
floatformat_m88110_ext, floatformat_m88110_harris_ext,
floatformat_arm_ext_big, floatformat_arm_ext_littlebyte_bigword,
floatformat_ia64_spill_big, floatformat_ia64_spill_little,
floatformat_ia64_quad_big, floatformat_ia64_quad_little): Update
for addition of split_half field.
gdb:
2007-11-07 Joseph Myers <joseph@codesourcery.com>
Daniel Jacobowitz <dan@codesourcery.com>
* gdbtypes.c (floatformats_ibm_long_double): New.
* gdbtypes.h (floatformats_ibm_long_double): Declare.
* ia64-tdep.c (floatformat_ia64_ext): Update for addition of
split_half field.
* mips-tdep.c (n32n64_floatformat_always_valid,
floatformat_n32n64_long_double_big, floatformats_n32n64_long):
Remove.
(mips_gdbarch_init): Use floatformats_ibm_long_double instead of
floatformats_n32n64_long.
* ppc-linux-tdep.c (ppc_linux_init_abi): Use 128-bit IBM long
double.
* doublest.c (convert_floatformat_to_doublest,
convert_doublest_to_floatformat): Handle split floating-point
formats.
* ppc-sysv-tdep.c (ppc_sysv_abi_push_dummy_call): Handle IBM long
double arguments.
(ppc64_sysv_abi_push_dummy_call): Likewise.
(do_ppc_sysv_return_value): Handle IBM long double return.
Diffstat (limited to 'libiberty/floatformat.c')
-rw-r--r-- | libiberty/floatformat.c | 209 |
1 files changed, 170 insertions, 39 deletions
diff --git a/libiberty/floatformat.c b/libiberty/floatformat.c index c5abbb1..07af726 100644 --- a/libiberty/floatformat.c +++ b/libiberty/floatformat.c @@ -56,6 +56,7 @@ Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. #endif #endif +static int mant_bits_set (const struct floatformat *, const unsigned char *); static unsigned long get_field (const unsigned char *, enum floatformat_byteorders, unsigned int, @@ -82,28 +83,32 @@ 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 + floatformat_always_valid, + NULL }; 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 + floatformat_always_valid, + NULL }; 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 + floatformat_always_valid, + NULL }; 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_always_valid, + NULL }; /* floatformat for IEEE double, little endian byte order, with big endian word @@ -114,7 +119,8 @@ 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 + floatformat_always_valid, + NULL }; /* floatformat for VAX. Not quite IEEE, but close enough. */ @@ -124,21 +130,24 @@ const struct floatformat floatformat_vax_f = floatformat_vax, 32, 0, 1, 8, 129, 0, 9, 23, floatformat_intbit_no, "floatformat_vax_f", - floatformat_always_valid + floatformat_always_valid, + NULL }; const struct floatformat floatformat_vax_d = { floatformat_vax, 64, 0, 1, 8, 129, 0, 9, 55, floatformat_intbit_no, "floatformat_vax_d", - floatformat_always_valid + floatformat_always_valid, + NULL }; const struct floatformat floatformat_vax_g = { floatformat_vax, 64, 0, 1, 11, 1025, 0, 12, 52, floatformat_intbit_no, "floatformat_vax_g", - floatformat_always_valid + floatformat_always_valid, + NULL }; static int floatformat_i387_ext_is_valid (const struct floatformat *fmt, @@ -170,7 +179,8 @@ 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 + floatformat_i387_ext_is_valid, + NULL }; const struct floatformat floatformat_m68881_ext = { @@ -178,7 +188,8 @@ const struct floatformat floatformat_m68881_ext = floatformat_big, 96, 0, 1, 15, 0x3fff, 0x7fff, 32, 64, floatformat_intbit_yes, "floatformat_m68881_ext", - floatformat_always_valid + floatformat_always_valid, + NULL }; const struct floatformat floatformat_i960_ext = { @@ -186,14 +197,16 @@ const struct floatformat floatformat_i960_ext = floatformat_little, 96, 16, 17, 15, 0x3fff, 0x7fff, 32, 64, floatformat_intbit_yes, "floatformat_i960_ext", - floatformat_always_valid + floatformat_always_valid, + NULL }; 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 + floatformat_always_valid, + NULL }; const struct floatformat floatformat_m88110_harris_ext = { @@ -202,7 +215,8 @@ const struct floatformat floatformat_m88110_harris_ext = floatformat_big,128, 0, 1, 11, 0x3ff, 0x7ff, 12, 52, floatformat_intbit_no, "floatformat_m88110_ext_harris", - floatformat_always_valid + floatformat_always_valid, + NULL }; const struct floatformat floatformat_arm_ext_big = { @@ -210,7 +224,8 @@ const struct floatformat floatformat_arm_ext_big = floatformat_big, 96, 0, 17, 15, 0x3fff, 0x7fff, 32, 64, floatformat_intbit_yes, "floatformat_arm_ext_big", - floatformat_always_valid + floatformat_always_valid, + NULL }; const struct floatformat floatformat_arm_ext_littlebyte_bigword = { @@ -218,35 +233,138 @@ const struct floatformat floatformat_arm_ext_littlebyte_bigword = floatformat_littlebyte_bigword, 96, 0, 17, 15, 0x3fff, 0x7fff, 32, 64, floatformat_intbit_yes, "floatformat_arm_ext_littlebyte_bigword", - floatformat_always_valid + floatformat_always_valid, + NULL }; 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 + floatformat_always_valid, + NULL }; 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 + floatformat_always_valid, + NULL }; 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 + floatformat_always_valid, + NULL }; 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 + floatformat_always_valid, + NULL +}; + +static int +floatformat_ibm_long_double_is_valid (const struct floatformat *fmt, + const void *from) +{ + const unsigned char *ufrom = (const unsigned char *) from; + const struct floatformat *hfmt = fmt->split_half; + long top_exp, bot_exp; + int top_nan = 0; + + top_exp = get_field (ufrom, hfmt->byteorder, hfmt->totalsize, + hfmt->exp_start, hfmt->exp_len); + bot_exp = get_field (ufrom + 8, hfmt->byteorder, hfmt->totalsize, + hfmt->exp_start, hfmt->exp_len); + + if (top_exp == hfmt->exp_nan) + top_nan = mant_bits_set (hfmt, ufrom); + + /* A NaN is valid with any low part. */ + if (top_nan) + return 1; + + /* An infinity, zero or denormal requires low part 0 (positive or + negative). */ + if (top_exp == hfmt->exp_nan || top_exp == 0) + { + unsigned int mant_bits, mant_off; + int mant_bits_left; + + if (bot_exp != 0) + return 0; + + return !mant_bits_set (hfmt, ufrom + 8); + } + + /* The top part is now a finite normal value. The long double value + is the sum of the two parts, and the top part must equal the + result of rounding the long double value to nearest double. Thus + the bottom part must be <= 0.5ulp of the top part in absolute + value, and if it is < 0.5ulp then the long double is definitely + valid. */ + if (bot_exp < top_exp - 53) + return 1; + if (bot_exp > top_exp - 53 && bot_exp != 0) + return 0; + if (bot_exp == 0) + { + /* The bottom part is 0 or denormal. Determine which, and if + denormal the first two set bits. */ + int first_bit = -1, second_bit = -1, cur_bit; + for (cur_bit = 0; cur_bit < hfmt->man_len; cur_bit++) + if (get_field (ufrom + 8, hfmt->byteorder, hfmt->totalsize, + hfmt->man_start + cur_bit, 1)) + { + if (first_bit == -1) + first_bit = cur_bit; + else + { + second_bit = cur_bit; + break; + } + } + /* Bottom part 0 is OK. */ + if (first_bit == -1) + return 1; + /* The real exponent of the bottom part is -first_bit. */ + if (-first_bit < top_exp - 53) + return 1; + if (-first_bit > top_exp - 53) + return 0; + /* The bottom part is at least 0.5ulp of the top part. For this + to be OK, the bottom part must be exactly 0.5ulp (i.e. no + more bits set) and the top part must have last bit 0. */ + if (second_bit != -1) + return 0; + return !get_field (ufrom, hfmt->byteorder, hfmt->totalsize, + hfmt->man_start + hfmt->man_len - 1, 1); + } + else + { + /* The bottom part is at least 0.5ulp of the top part. For this + to be OK, it must be exactly 0.5ulp (i.e. no explicit bits + set) and the top part must have last bit 0. */ + if (get_field (ufrom, hfmt->byteorder, hfmt->totalsize, + hfmt->man_start + hfmt->man_len - 1, 1)) + return 0; + return !mant_bits_set (hfmt, ufrom + 8); + } +} + +const struct floatformat floatformat_ibm_long_double = +{ + floatformat_big, 128, 0, 1, 11, 1023, 2047, 12, 52, + floatformat_intbit_no, + "floatformat_ibm_long_double", + floatformat_always_valid, + &floatformat_ieee_double_big }; @@ -254,6 +372,30 @@ const struct floatformat floatformat_ia64_quad_little = #define min(a, b) ((a) < (b) ? (a) : (b)) #endif +/* Return 1 if any bits are explicitly set in the mantissa of UFROM, + format FMT, 0 otherwise. */ +static int +mant_bits_set (const struct floatformat *fmt, const unsigned char *ufrom) +{ + unsigned int mant_bits, mant_off; + int mant_bits_left; + + mant_off = fmt->man_start; + mant_bits_left = fmt->man_len; + 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) + return 1; + + mant_off += mant_bits; + mant_bits_left -= mant_bits; + } + return 0; +} + /* 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 @@ -310,6 +452,10 @@ floatformat_to_double (const struct floatformat *fmt, int mant_bits_left; int special_exponent; /* It's a NaN, denorm or zero */ + /* Split values are not handled specially, since the top half has + the correctly rounded double value (in the only supported case of + split values). */ + exponent = get_field (ufrom, fmt->byteorder, fmt->totalsize, fmt->exp_start, fmt->exp_len); @@ -318,26 +464,7 @@ floatformat_to_double (const struct floatformat *fmt, 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; - } + int nan = mant_bits_set (fmt, ufrom); /* On certain systems (such as GNU/Linux), the use of the INFINITY macro below may generate a warning that can not be @@ -474,6 +601,10 @@ floatformat_from_double (const struct floatformat *fmt, dfrom = *from; memset (uto, 0, fmt->totalsize / FLOATFORMAT_CHAR_BIT); + /* Split values are not handled specially, since a bottom half of + zero is correct for any value representable as double (in the + only supported case of split values). */ + /* If negative, set the sign bit. */ if (dfrom < 0) { |