diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-128ibm/math_ldbl.h')
| -rw-r--r-- | sysdeps/ieee754/ldbl-128ibm/math_ldbl.h | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128ibm/math_ldbl.h b/sysdeps/ieee754/ldbl-128ibm/math_ldbl.h new file mode 100644 index 0000000..e7e1b96 --- /dev/null +++ b/sysdeps/ieee754/ldbl-128ibm/math_ldbl.h @@ -0,0 +1,124 @@ +#ifndef _MATH_PRIVATE_H_ +#error "Never use <math_ldbl.h> directly; include <math_private.h> instead." +#endif + +#include <sysdeps/ieee754/ldbl-128/math_ldbl.h> + +#define EXTRACT_IBM_EXTENDED_MANTISSA(hi64, lo64, expnt, ibm_ext_ldbl) \ + do \ + { \ + /* We have 105 bits of mantissa plus one implicit digit. Since \ + 106 bits are representable without the rest using hexadecimal \ + digits we use only the implicit digits for the number before \ + the decimal point. */ \ + unsigned long long hi, lo; \ + int ediff; \ + union ibm_extended_long_double eldbl; \ + eldbl.d = ibm_ext_ldbl; \ + expnt = eldbl.ieee.exponent - IBM_EXTENDED_LONG_DOUBLE_BIAS; \ + \ + lo = ((long long)eldbl.ieee.mantissa2 << 32) | eldbl.ieee.mantissa3; \ + hi = ((long long)eldbl.ieee.mantissa0 << 32) | eldbl.ieee.mantissa1; \ + /* If the lower double is not a denomal or zero then set the hidden \ + 53rd bit. */ \ + if (eldbl.ieee.exponent2 > 0x001) \ + { \ + lo |= (1ULL << 52); \ + lo = lo << 7; /* pre-shift lo to match ieee854. */ \ + /* The lower double is normalized separately from the upper. We \ + may need to adjust the lower manitissa to reflect this. */ \ + ediff = eldbl.ieee.exponent - eldbl.ieee.exponent2; \ + if (ediff > 53) \ + lo = lo >> (ediff-53); \ + } \ + hi |= (1ULL << 52); \ + \ + if ((eldbl.ieee.negative != eldbl.ieee.negative2) \ + && ((eldbl.ieee.exponent2 != 0) && (lo != 0LL))) \ + { \ + hi--; \ + lo = (1ULL << 60) - lo; \ + if (hi < (1ULL << 52)) \ + { \ + /* we have a borrow from the hidden bit, so shift left 1. */ \ + hi = (hi << 1) | (lo >> 59); \ + lo = 0xfffffffffffffffLL & (lo << 1); \ + expnt--; \ + } \ + } \ + lo64 = (hi << 60) | lo; \ + hi64 = hi >> 4; \ + } \ + while (0) + +#define INSERT_IBM_EXTENDED_MANTISSA(ibm_ext_ldbl, sign, expnt, hi64, lo64) \ + do \ + { \ + union ibm_extended_long_double u; \ + unsigned long hidden2, lzcount; \ + unsigned long long hi, lo; \ + \ + u.ieee.negative = sign; \ + u.ieee.negative2 = sign; \ + u.ieee.exponent = expnt + IBM_EXTENDED_LONG_DOUBLE_BIAS; \ + u.ieee.exponent2 = expnt-53 + IBM_EXTENDED_LONG_DOUBLE_BIAS; \ + /* Expect 113 bits (112 bits + hidden) right justified in two longs. \ + The low order 53 bits (52 + hidden) go into the lower double */ \ + lo = (lo64 >> 7)& ((1ULL << 53) - 1); \ + hidden2 = (lo64 >> 59) & 1ULL; \ + /* The high order 53 bits (52 + hidden) go into the upper double */ \ + hi = (lo64 >> 60) & ((1ULL << 11) - 1); \ + hi |= (hi64 << 4); \ + \ + if (lo != 0LL) \ + { \ + /* hidden2 bit of low double controls rounding of the high double. \ + If hidden2 is '1' then round up hi and adjust lo (2nd mantissa) \ + plus change the sign of the low double to compensate. */ \ + if (hidden2) \ + { \ + hi++; \ + u.ieee.negative2 = !sign; \ + lo = (1ULL << 53) - lo; \ + } \ + /* The hidden bit of the lo mantissa is zero so we need to \ + normalize the it for the low double. Shift it left until the \ + hidden bit is '1' then adjust the 2nd exponent accordingly. */ \ + \ + if (sizeof (lo) == sizeof (long)) \ + lzcount = __builtin_clzl (lo); \ + else if ((lo >> 32) != 0) \ + lzcount = __builtin_clzl ((long) (lo >> 32)); \ + else \ + lzcount = __builtin_clzl ((long) lo) + 32; \ + lzcount = lzcount - 11; \ + if (lzcount > 0) \ + { \ + int expnt2 = u.ieee.exponent2 - lzcount; \ + if (expnt2 >= 1) \ + { \ + /* Not denormal. Normalize and set low exponent. */ \ + lo = lo << lzcount; \ + u.ieee.exponent2 = expnt2; \ + } \ + else \ + { \ + /* Is denormal. */ \ + lo = lo << (lzcount + expnt2); \ + u.ieee.exponent2 = 0; \ + } \ + } \ + } \ + else \ + { \ + u.ieee.negative2 = 0; \ + u.ieee.exponent2 = 0; \ + } \ + \ + u.ieee.mantissa3 = lo & ((1ULL << 32) - 1); \ + u.ieee.mantissa2 = (lo >> 32) & ((1ULL << 20) - 1); \ + u.ieee.mantissa1 = hi & ((1ULL << 32) - 1); \ + u.ieee.mantissa0 = (hi >> 32) & ((1ULL << 20) - 1); \ + ibm_ext_ldbl = u.d; \ + } \ + while (0) |