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real: Fix roundeven on inf/nan [PR93663]

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As can be seen in the testcase, roundeven with inf or nan arguments
ICE because of those asserts where nothing prevents from is_halfway_below
being called with those arguments.

The following patch fixes that by just returning false for rvc_inf/rvc_nan
like it returns for rvc_zero, so that we handle roundeven with all those
values as round.  Inf/NaN are not halfway in between two integers...

2020-02-12  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/93663
	* real.c (is_even): Make static.  Function comment fix.
	(is_halfway_below): Make static, don't assert R is not inf/nan,
	instead return false for those.  Small formatting fixes.

	* gcc.dg/torture/builtin-round-roundeven.c (main): Add tests
	for DBL_MAX, inf, their negations and nan.
This commit is contained in:
Jakub Jelinek 2020-02-12 22:14:27 +01:00
parent b32a3f3243
commit 3f3932a0ec
4 changed files with 29 additions and 14 deletions
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7
gcc/ChangeLog
View file

@ -1,3 +1,10 @@
2020-02-12 Jakub Jelinek <jakub@redhat.com>
PR middle-end/93663
* real.c (is_even): Make static. Function comment fix.
(is_halfway_below): Make static, don't assert R is not inf/nan,
instead return false for those. Small formatting fixes.
2020-02-12 Martin Sebor <msebor@redhat.com>
PR middle-end/93646

20
gcc/real.c
View file

@ -5150,10 +5150,10 @@ real_round (REAL_VALUE_TYPE *r, format_helper fmt,
real_convert (r, fmt, r);
}
/* Return true including 0 if integer part of R is even, else return
/* Return true (including 0) if integer part of R is even, else return
false. The function is not valid for rvc_inf and rvc_nan classes. */
bool
static bool
is_even (REAL_VALUE_TYPE *r)
{
gcc_assert (r->cl != rvc_inf);
@ -5184,16 +5184,12 @@ is_even (REAL_VALUE_TYPE *r)
}
/* Return true if R is halfway between two integers, else return
false. The function is not valid for rvc_inf and rvc_nan classes. */
false. */
bool
static bool
is_halfway_below (const REAL_VALUE_TYPE *r)
{
gcc_assert (r->cl != rvc_inf);
gcc_assert (r->cl != rvc_nan);
int i;
if (r->cl == rvc_zero)
if (r->cl != rvc_normal)
return false;
/* For numbers (-0.5,0) and (0,0.5). */
@ -5205,13 +5201,13 @@ is_halfway_below (const REAL_VALUE_TYPE *r)
unsigned int n = SIGNIFICAND_BITS - REAL_EXP (r) - 1;
int w = n / HOST_BITS_PER_LONG;
for (i = 0; i < w; ++i)
for (int i = 0; i < w; ++i)
if (r->sig[i] != 0)
return false;
unsigned long num = ((unsigned long)1 << (n % HOST_BITS_PER_LONG));
unsigned long num = 1UL << (n % HOST_BITS_PER_LONG);
if (((r->sig[w] & num) != 0) && ((r->sig[w] & (num-1)) == 0))
if ((r->sig[w] & num) != 0 && (r->sig[w] & (num - 1)) == 0)
return true;
}
return false;

6
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,9 @@
2020-02-12 Jakub Jelinek <jakub@redhat.com>
PR middle-end/93663
* gcc.dg/torture/builtin-round-roundeven.c (main): Add tests
for DBL_MAX, inf, their negations and nan.
2020-02-12 Martin Sebor <msebor@redhat.com>
PR middle-end/93646

10
gcc/testsuite/gcc.dg/torture/builtin-round-roundeven.c
View file

@ -18,6 +18,13 @@ main (void)
TEST(roundeven, -1.5, -2);
TEST(roundeven, 3.499, 3);
TEST(roundeven, 3.501, 4);
TEST(roundeven, __DBL_MAX__, __DBL_MAX__);
TEST(roundeven, -__DBL_MAX__, -__DBL_MAX__);
TEST(roundeven, __builtin_inf (), __builtin_inf ());
TEST(roundeven, -__builtin_inf (), -__builtin_inf ());
if (!__builtin_isnan (__builtin_roundeven (__builtin_nan (""))))
link_error (__LINE__);
if (__builtin_copysign (1, __builtin_roundeven (-0.5)) != -1)
link_error (__LINE__);
@ -31,6 +38,5 @@ main (void)
link_error (__LINE__);
if (__builtin_copysign (-1, __builtin_roundeven (0.25)) != 1)
link_error (__LINE__);
return 0;
return 0;
}