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libgcc: Fix a bug in _BitInt -> dfp conversions

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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.

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.
This commit is contained in:
Jakub Jelinek 2024-02-10 12:51:39 +01:00
parent b2684e5512
commit 1e87fcf200
3 changed files with 3 additions and 3 deletions
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2
libgcc/soft-fp/floatbitintdd.c
View File

@ -114,7 +114,7 @@ __bid_floatbitintdd (const UBILtype *i, SItype iprec)
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
{

2
libgcc/soft-fp/floatbitintsd.c
View File

@ -113,7 +113,7 @@ __bid_floatbitintsd (const UBILtype *i, SItype iprec)
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
{

2
libgcc/soft-fp/floatbitinttd.c
View File

@ -113,7 +113,7 @@ __bid_floatbitinttd (const UBILtype *i, SItype iprec)
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
{