diff options
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/real.c | 93 | ||||
| -rw-r--r-- | gcc/real.h | 1 |
3 files changed, 100 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 9709a75..f265ac7 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2002-09-29 David Edelsohn <edelsohn@gnu.org> + + * real.h (ibm_extended_format): Declare. + * real.c (encode_ibm_extended, decode_ibm_extended): New + functions. + 2002-09-29 Kaveh R. Ghazi <ghazi@caip.rutgers.edu> * darwin-protos.h (darwin_asm_output_dwarf_delta): Prototype. @@ -2951,6 +2951,99 @@ const struct real_format ieee_extended_intel_128_format = }; +/* IBM 128-bit extended precision format: a pair of IEEE double precision + numbers whose sum is equal to the extended precision value. The number + with greater magnitude is first. This format has the same magnitude + range as an IEEE double precision value, but effectively 106 bits of + significand precision. Infinity and NaN are represented by their IEEE + double precision value stored in the first number, the second number is + ignored. Zeroes, Infinities, and NaNs are set in both doubles + due to precedent. */ + +static void encode_ibm_extended PARAMS ((const struct real_format *fmt, + long *, const REAL_VALUE_TYPE *)); +static void decode_ibm_extended PARAMS ((const struct real_format *, + REAL_VALUE_TYPE *, const long *)); + +static void +encode_ibm_extended (fmt, buf, r) + const struct real_format *fmt ATTRIBUTE_UNUSED; + long *buf; + const REAL_VALUE_TYPE *r; +{ + REAL_VALUE_TYPE u, v; + + switch (r->class) + { + case rvc_zero: + /* Both doubles have sign bit set. */ + buf[0] = FLOAT_WORDS_BIG_ENDIAN ? r->sign << 31 : 0; + buf[1] = FLOAT_WORDS_BIG_ENDIAN ? 0 : r->sign << 31; + buf[2] = buf[0]; + buf[3] = buf[1]; + break; + + case rvc_inf: + case rvc_nan: + /* Both doubles set to Inf / NaN. */ + encode_ieee_double (&ieee_double_format, &buf[0], r); + buf[2] = buf[0]; + buf[3] = buf[1]; + return; + + case rvc_normal: + /* u = IEEE double precision portion of significand. */ + u = *r; + clear_significand_below (&u, SIGNIFICAND_BITS - 53); + + /* v = remainder containing additional 53 bits of significand. */ + do_add (&v, r, &u, 1); + + encode_ieee_double (&ieee_double_format, &buf[0], &u); + encode_ieee_double (&ieee_double_format, &buf[2], &v); + break; + + default: + abort (); + } +} + +static void +decode_ibm_extended (fmt, r, buf) + const struct real_format *fmt ATTRIBUTE_UNUSED; + REAL_VALUE_TYPE *r; + const long *buf; +{ + REAL_VALUE_TYPE u, v; + + decode_ieee_double (&ieee_double_format, &u, &buf[0]); + + if (u.class != rvc_zero && u.class != rvc_inf && u.class != rvc_nan) + { + decode_ieee_double (&ieee_double_format, &v, &buf[2]); + do_add (r, &u, &v, 0); + } + else + *r = u; +} + +const struct real_format ibm_extended_format = + { + encode_ibm_extended, + decode_ibm_extended, + 2, + 1, + 53 + 53, + -1021, + 1024, + true, + true, + true, + true, + true + }; + + /* IEEE quad precision format. */ static void encode_ieee_quad PARAMS ((const struct real_format *fmt, @@ -216,6 +216,7 @@ extern const struct real_format ieee_double_format; extern const struct real_format ieee_extended_motorola_format; extern const struct real_format ieee_extended_intel_96_format; extern const struct real_format ieee_extended_intel_128_format; +extern const struct real_format ibm_extended_format; extern const struct real_format ieee_quad_format; extern const struct real_format vax_f_format; extern const struct real_format vax_d_format; |