libgcc2.c: Correct DI/TI -> SF/DF conversions

FSTYPE FUNC (DWtype u) in libgcc2.c, which converts DI/TI to SF/DF, has

  /* No leading bits means u == minimum.  */
  if (count == 0)
    return -(Wtype_MAXp1_F * (Wtype_MAXp1_F / 2));

in the third case (where actually count == 0 only means the high part is
minimum).  It should be:

  /* No leading bits means u == minimum.  */
  if (count == 0)
    return Wtype_MAXp1_F * (FSTYPE) (hi | ((UWtype) u != 0));

instead.

gcc/testsuite/

2019-01-23  H.J. Lu  <hongjiu.lu@intel.com>

	PR libgcc/88931
	* gcc.dg/torture/fp-int-convert-timode-1.c: New test.
	* gcc.dg/torture/fp-int-convert-timode-2.c: Likewise.
	* gcc.dg/torture/fp-int-convert-timode-3.c: Likewise.
	* gcc.dg/torture/fp-int-convert-timode-4.c: Likewise.

libgcc/

2019-01-23  Joseph Myers  <joseph@codesourcery.com>

	PR libgcc/88931
	* libgcc2.c (FSTYPE FUNC (DWtype u)): Correct no leading bits
	case.

From-SVN: r268216
This commit is contained in:
H.J. Lu 2019-01-23 13:41:59 -08:00
parent 8c5b33788d
commit 6395ba73f8
7 changed files with 121 additions and 1 deletions

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@ -1,3 +1,11 @@
2019-01-23 H.J. Lu <hongjiu.lu@intel.com>
PR libgcc/88931
* gcc.dg/torture/fp-int-convert-timode-1.c: New test.
* gcc.dg/torture/fp-int-convert-timode-2.c: Likewise.
* gcc.dg/torture/fp-int-convert-timode-3.c: Likewise.
* gcc.dg/torture/fp-int-convert-timode-4.c: Likewise.
2019-01-23 Uroš Bizjak <ubizjak@gmail.com>
PR target/88998

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@ -0,0 +1,25 @@
/* Test for correct rounding of conversions from __int128 to
float. */
/* { dg-do run } */
/* { dg-require-effective-target int128 } */
/* { dg-options "-frounding-math" } */
#include <fenv.h>
#include <stdlib.h>
int
main (void)
{
volatile unsigned long long h = 0x8000000000000000LL;
volatile unsigned long long l = 0xdLL;
volatile unsigned __int128 u128 = (((unsigned __int128) h) << 64) | l;
volatile __int128 s128 = u128;
fesetround (FE_TONEAREST);
float fs = s128;
if (fs != -0x1p+127)
abort ();
double ds = s128;
if (ds != -0x1p+127)
abort ();
exit (0);
}

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@ -0,0 +1,27 @@
/* Test for correct rounding of conversions from __int128 to
float. */
/* { dg-do run } */
/* { dg-require-effective-target int128 } */
/* { dg-options "-frounding-math" } */
#include <fenv.h>
#include <stdlib.h>
int
main (void)
{
#ifdef FE_DOWNWARD
volatile unsigned long long h = 0x8000000000000000LL;
volatile unsigned long long l = 0xdLL;
volatile unsigned __int128 u128 = (((unsigned __int128) h) << 64) | l;
volatile __int128 s128 = u128;
fesetround (FE_DOWNWARD);
float fs = s128;
if (fs != -0x1p+127)
abort ();
double ds = s128;
if (ds != -0x1p+127)
abort ();
#endif
exit (0);
}

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@ -0,0 +1,27 @@
/* Test for correct rounding of conversions from __int128 to
float. */
/* { dg-do run } */
/* { dg-require-effective-target int128 } */
/* { dg-options "-frounding-math" } */
#include <fenv.h>
#include <stdlib.h>
int
main (void)
{
#ifdef FE_UPWARD
volatile unsigned long long h = 0x8000000000000000LL;
volatile unsigned long long l = 0xdLL;
volatile unsigned __int128 u128 = (((unsigned __int128) h) << 64) | l;
volatile __int128 s128 = u128;
fesetround (FE_UPWARD);
float fs = s128;
if (fs != -0x1.fffffep+126)
abort ();
double ds = s128;
if (ds != -0x1.fffffffffffffp+126)
abort ();
#endif
exit (0);
}

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@ -0,0 +1,27 @@
/* Test for correct rounding of conversions from __int128 to
float. */
/* { dg-do run } */
/* { dg-require-effective-target int128 } */
/* { dg-options "-frounding-math" } */
#include <fenv.h>
#include <stdlib.h>
int
main (void)
{
#ifdef FE_TOWARDZERO
volatile unsigned long long h = 0x8000000000000000LL;
volatile unsigned long long l = 0xdLL;
volatile unsigned __int128 u128 = (((unsigned __int128) h) << 64) | l;
volatile __int128 s128 = u128;
fesetround (FE_TOWARDZERO);
float fs = s128;
if (fs != -0x1.fffffep+126)
abort ();
double ds = s128;
if (ds != -0x1.fffffffffffffp+126)
abort ();
#endif
exit (0);
}

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@ -1,3 +1,9 @@
2019-01-23 Joseph Myers <joseph@codesourcery.com>
PR libgcc/88931
* libgcc2.c (FSTYPE FUNC (DWtype u)): Correct no leading bits
case.
2019-01-18 Martin Liska <mliska@suse.cz>
* libgcov-profiler.c (__gcov_indirect_call_profiler_v2): Rename

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@ -1684,7 +1684,7 @@ FUNC (DWtype u)
/* No leading bits means u == minimum. */
if (count == 0)
return -(Wtype_MAXp1_F * (Wtype_MAXp1_F / 2));
return Wtype_MAXp1_F * (FSTYPE) (hi | ((UWtype) u != 0));
shift = 1 + W_TYPE_SIZE - count;