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author | Anton Samokhvalov <pg83@yandex.ru> | 2022-02-10 16:45:15 +0300 |
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committer | Daniil Cherednik <dcherednik@yandex-team.ru> | 2022-02-10 16:45:15 +0300 |
commit | 72cb13b4aff9bc9cf22e49251bc8fd143f82538f (patch) | |
tree | da2c34829458c7d4e74bdfbdf85dff449e9e7fb8 /contrib/libs/cxxsupp/builtins/ppc/fixunstfdi.c | |
parent | 778e51ba091dc39e7b7fcab2b9cf4dbedfb6f2b5 (diff) | |
download | ydb-72cb13b4aff9bc9cf22e49251bc8fd143f82538f.tar.gz |
Restoring authorship annotation for Anton Samokhvalov <pg83@yandex.ru>. Commit 1 of 2.
Diffstat (limited to 'contrib/libs/cxxsupp/builtins/ppc/fixunstfdi.c')
-rw-r--r-- | contrib/libs/cxxsupp/builtins/ppc/fixunstfdi.c | 118 |
1 files changed, 59 insertions, 59 deletions
diff --git a/contrib/libs/cxxsupp/builtins/ppc/fixunstfdi.c b/contrib/libs/cxxsupp/builtins/ppc/fixunstfdi.c index 5e6e2cedf6..277f30ecca 100644 --- a/contrib/libs/cxxsupp/builtins/ppc/fixunstfdi.c +++ b/contrib/libs/cxxsupp/builtins/ppc/fixunstfdi.c @@ -1,59 +1,59 @@ -/* This file is distributed under the University of Illinois Open Source - * License. See LICENSE.TXT for details. - */ - -/* uint64_t __fixunstfdi(long double x); */ -/* This file implements the PowerPC 128-bit double-double -> uint64_t conversion */ - -#include "DD.h" - -uint64_t __fixunstfdi(long double input) -{ - const DD x = { .ld = input }; - const doublebits hibits = { .d = x.s.hi }; - - const uint32_t highWordMinusOne = (uint32_t)(hibits.x >> 32) - UINT32_C(0x3ff00000); - - /* If (1.0 - tiny) <= input < 0x1.0p64: */ - if (UINT32_C(0x04000000) > highWordMinusOne) - { - const int unbiasedHeadExponent = highWordMinusOne >> 20; - - uint64_t result = hibits.x & UINT64_C(0x000fffffffffffff); /* mantissa(hi) */ - result |= UINT64_C(0x0010000000000000); /* matissa(hi) with implicit bit */ - result <<= 11; /* mantissa(hi) left aligned in the int64 field. */ - - /* If the tail is non-zero, we need to patch in the tail bits. */ - if (0.0 != x.s.lo) - { - const doublebits lobits = { .d = x.s.lo }; - int64_t tailMantissa = lobits.x & INT64_C(0x000fffffffffffff); - tailMantissa |= INT64_C(0x0010000000000000); - - /* At this point we have the mantissa of |tail| */ - - const int64_t negationMask = ((int64_t)(lobits.x)) >> 63; - tailMantissa = (tailMantissa ^ negationMask) - negationMask; - - /* Now we have the mantissa of tail as a signed 2s-complement integer */ - - const int biasedTailExponent = (int)(lobits.x >> 52) & 0x7ff; - - /* Shift the tail mantissa into the right position, accounting for the - * bias of 11 that we shifted the head mantissa by. - */ - tailMantissa >>= (unbiasedHeadExponent - (biasedTailExponent - (1023 - 11))); - - result += tailMantissa; - } - - result >>= (63 - unbiasedHeadExponent); - return result; - } - - /* Edge cases are handled here, with saturation. */ - if (1.0 > x.s.hi) - return UINT64_C(0); - else - return UINT64_MAX; -} +/* This file is distributed under the University of Illinois Open Source + * License. See LICENSE.TXT for details. + */ + +/* uint64_t __fixunstfdi(long double x); */ +/* This file implements the PowerPC 128-bit double-double -> uint64_t conversion */ + +#include "DD.h" + +uint64_t __fixunstfdi(long double input) +{ + const DD x = { .ld = input }; + const doublebits hibits = { .d = x.s.hi }; + + const uint32_t highWordMinusOne = (uint32_t)(hibits.x >> 32) - UINT32_C(0x3ff00000); + + /* If (1.0 - tiny) <= input < 0x1.0p64: */ + if (UINT32_C(0x04000000) > highWordMinusOne) + { + const int unbiasedHeadExponent = highWordMinusOne >> 20; + + uint64_t result = hibits.x & UINT64_C(0x000fffffffffffff); /* mantissa(hi) */ + result |= UINT64_C(0x0010000000000000); /* matissa(hi) with implicit bit */ + result <<= 11; /* mantissa(hi) left aligned in the int64 field. */ + + /* If the tail is non-zero, we need to patch in the tail bits. */ + if (0.0 != x.s.lo) + { + const doublebits lobits = { .d = x.s.lo }; + int64_t tailMantissa = lobits.x & INT64_C(0x000fffffffffffff); + tailMantissa |= INT64_C(0x0010000000000000); + + /* At this point we have the mantissa of |tail| */ + + const int64_t negationMask = ((int64_t)(lobits.x)) >> 63; + tailMantissa = (tailMantissa ^ negationMask) - negationMask; + + /* Now we have the mantissa of tail as a signed 2s-complement integer */ + + const int biasedTailExponent = (int)(lobits.x >> 52) & 0x7ff; + + /* Shift the tail mantissa into the right position, accounting for the + * bias of 11 that we shifted the head mantissa by. + */ + tailMantissa >>= (unbiasedHeadExponent - (biasedTailExponent - (1023 - 11))); + + result += tailMantissa; + } + + result >>= (63 - unbiasedHeadExponent); + return result; + } + + /* Edge cases are handled here, with saturation. */ + if (1.0 > x.s.hi) + return UINT64_C(0); + else + return UINT64_MAX; +} |