Message ID | ZcdIFVDl6Bby8QZG@tucnak |
---|---|
State | New |
Headers | show |
Series | libgcc: Fix a bug in _BitInt -> dfp conversions | expand |
> Am 10.02.2024 um 10:56 schrieb Jakub Jelinek <jakub@redhat.com>: > > Hi! > > The ia32 _BitInt support revealed a bug in floatbitint?d.c. > As can be even guessed from how the code is written in the loop, > the intention was to set inexact to non-zero whenever the remainder > after division wasn't zero, but I've ended up just checking whether > the 2 least significant limbs of the remainder were non-zero. > Now, in the dfp/bitint-4.c test in one case the remainder happens > to have least significant 64 bits zero and then the higher limbs are > non-zero; with 32-bit limbs that means 2 least significant limbs are zero > and so the code acted as if it was exactly divisible. > > Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux > (including the _BitInt enablement there), ok for trunk? Ok Richard > 2024-02-10 Jakub Jelinek <jakub@redhat.com> > > * soft-fp/floatbitintdd.c (__bid_floatbitintdd): Or in all remainder > limbs into inexact rather than just first two. > * soft-fp/floatbitintsd.c (__bid_floatbitintsd): Likewise. > * soft-fp/floatbitinttd.c (__bid_floatbitinttd): Likewise. > > --- libgcc/soft-fp/floatbitintdd.c.jj 2024-02-09 17:11:47.095675716 +0100 > +++ libgcc/soft-fp/floatbitintdd.c 2024-02-09 18:22:25.786674139 +0100 > @@ -114,7 +114,7 @@ __bid_floatbitintdd (const UBILtype *i, > buf + BITINT_END (q_limbs - 1, 0), q_limbs); > inexact = buf[q_limbs + pow10_limbs]; > for (j = 1; j < pow10_limbs; ++j) > - inexact |= buf[q_limbs + pow10_limbs + 1]; > + inexact |= buf[q_limbs + pow10_limbs + j]; > } > else > { > --- libgcc/soft-fp/floatbitintsd.c.jj 2023-09-06 17:34:04.978510447 +0200 > +++ libgcc/soft-fp/floatbitintsd.c 2024-02-09 18:21:50.949158569 +0100 > @@ -113,7 +113,7 @@ __bid_floatbitintsd (const UBILtype *i, > buf + BITINT_END (q_limbs - 1, 0), q_limbs); > inexact = buf[q_limbs + pow10_limbs]; > for (j = 1; j < pow10_limbs; ++j) > - inexact |= buf[q_limbs + pow10_limbs + 1]; > + inexact |= buf[q_limbs + pow10_limbs + j]; > } > else > { > --- libgcc/soft-fp/floatbitinttd.c.jj 2024-02-09 17:14:17.485578556 +0100 > +++ libgcc/soft-fp/floatbitinttd.c 2024-02-09 18:21:34.409388566 +0100 > @@ -113,7 +113,7 @@ __bid_floatbitinttd (const UBILtype *i, > buf + BITINT_END (q_limbs - 1, 0), q_limbs); > inexact = buf[q_limbs + pow10_limbs]; > for (j = 1; j < pow10_limbs; ++j) > - inexact |= buf[q_limbs + pow10_limbs + 1]; > + inexact |= buf[q_limbs + pow10_limbs + j]; > } > else > { > > Jakub >
--- libgcc/soft-fp/floatbitintdd.c.jj 2024-02-09 17:11:47.095675716 +0100 +++ libgcc/soft-fp/floatbitintdd.c 2024-02-09 18:22:25.786674139 +0100 @@ -114,7 +114,7 @@ __bid_floatbitintdd (const UBILtype *i, buf + BITINT_END (q_limbs - 1, 0), q_limbs); inexact = buf[q_limbs + pow10_limbs]; for (j = 1; j < pow10_limbs; ++j) - inexact |= buf[q_limbs + pow10_limbs + 1]; + inexact |= buf[q_limbs + pow10_limbs + j]; } else { --- libgcc/soft-fp/floatbitintsd.c.jj 2023-09-06 17:34:04.978510447 +0200 +++ libgcc/soft-fp/floatbitintsd.c 2024-02-09 18:21:50.949158569 +0100 @@ -113,7 +113,7 @@ __bid_floatbitintsd (const UBILtype *i, buf + BITINT_END (q_limbs - 1, 0), q_limbs); inexact = buf[q_limbs + pow10_limbs]; for (j = 1; j < pow10_limbs; ++j) - inexact |= buf[q_limbs + pow10_limbs + 1]; + inexact |= buf[q_limbs + pow10_limbs + j]; } else { --- libgcc/soft-fp/floatbitinttd.c.jj 2024-02-09 17:14:17.485578556 +0100 +++ libgcc/soft-fp/floatbitinttd.c 2024-02-09 18:21:34.409388566 +0100 @@ -113,7 +113,7 @@ __bid_floatbitinttd (const UBILtype *i, buf + BITINT_END (q_limbs - 1, 0), q_limbs); inexact = buf[q_limbs + pow10_limbs]; for (j = 1; j < pow10_limbs; ++j) - inexact |= buf[q_limbs + pow10_limbs + 1]; + inexact |= buf[q_limbs + pow10_limbs + j]; } else {