| Message ID | 20161208185149.22707-1-vapier@gentoo.org |
|---|---|
| State | New |
| Headers | show |
On 12/08/2016 10:51 AM, Mike Frysinger wrote: > __ceil (double x) > { > + if (isnan (x)) > + return x + x; > + > if (isless (fabs (x), 9007199254740992.0)) /* 1 << DBL_MANT_DIG */ > { > double tmp1, new_x; Probably better to test for nan in the else of this if, since the isless is surely more likely than the nan. That goes for all of the changes. r~
On 08 Dec 2016 20:01, Richard Henderson wrote: > On 12/08/2016 10:51 AM, Mike Frysinger wrote: > > __ceil (double x) > > { > > + if (isnan (x)) > > + return x + x; > > + > > if (isless (fabs (x), 9007199254740992.0)) /* 1 << DBL_MANT_DIG */ > > { > > double tmp1, new_x; > > Probably better to test for nan in the else of this if, since the isless is > surely more likely than the nan. > > That goes for all of the changes. i guess fabs(NaN) and isless(NaN, ...) isn't a problem ? would it be equiv to do ? if (__glibc_unlikely (isnan (x))) -mike
On 12/08/2016 08:11 PM, Mike Frysinger wrote: > On 08 Dec 2016 20:01, Richard Henderson wrote: >> On 12/08/2016 10:51 AM, Mike Frysinger wrote: >>> __ceil (double x) >>> { >>> + if (isnan (x)) >>> + return x + x; >>> + >>> if (isless (fabs (x), 9007199254740992.0)) /* 1 << DBL_MANT_DIG */ >>> { >>> double tmp1, new_x; >> >> Probably better to test for nan in the else of this if, since the isless is >> surely more likely than the nan. >> >> That goes for all of the changes. > > i guess fabs(NaN) and isless(NaN, ...) isn't a problem ? No, that's fine. > would it be equiv to do ? > if (__glibc_unlikely (isnan (x))) No, since that test would still happen first. I think that if (isless(...)) ... else if (isnan(x)) return x + x; is better for the average case. r~
diff --git a/ChangeLog b/ChangeLog index 24ce4491dc80..ad8921af8858 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2016-08-02 Aurelien Jarno <aurelien@aurel32.net> + + * sysdeps/alpha/fpu/s_ceil.c (__ceil): Add argument with itself + when it is a NaN. + [_IEEE_FP_INEXACT] Remove. + * sysdeps/alpha/fpu/s_ceilf.c (__ceilf): Likewise. + 2016-11-23 Matthew Fortune <Matthew.Fortune@imgtec.com> Maciej W. Rozycki <macro@imgtec.com> diff --git a/sysdeps/alpha/fpu/s_ceil.c b/sysdeps/alpha/fpu/s_ceil.c index c1ff864d4b86..e9c350af1cc0 100644 --- a/sysdeps/alpha/fpu/s_ceil.c +++ b/sysdeps/alpha/fpu/s_ceil.c @@ -26,17 +26,16 @@ double __ceil (double x) { + if (isnan (x)) + return x + x; + if (isless (fabs (x), 9007199254740992.0)) /* 1 << DBL_MANT_DIG */ { double tmp1, new_x; new_x = -x; __asm ( -#ifdef _IEEE_FP_INEXACT - "cvttq/svim %2,%1\n\t" -#else "cvttq/svm %2,%1\n\t" -#endif "cvtqt/m %1,%0\n\t" : "=f"(new_x), "=&f"(tmp1) : "f"(new_x)); diff --git a/sysdeps/alpha/fpu/s_ceilf.c b/sysdeps/alpha/fpu/s_ceilf.c index 7e63a6fe94e7..77e01a99f743 100644 --- a/sysdeps/alpha/fpu/s_ceilf.c +++ b/sysdeps/alpha/fpu/s_ceilf.c @@ -25,6 +25,9 @@ float __ceilf (float x) { + if (isnanf (x)) + return x + x; + if (isless (fabsf (x), 16777216.0f)) /* 1 << FLT_MANT_DIG */ { /* Note that Alpha S_Floating is stored in registers in a @@ -36,11 +39,7 @@ __ceilf (float x) new_x = -x; __asm ("cvtst/s %3,%2\n\t" -#ifdef _IEEE_FP_INEXACT - "cvttq/svim %2,%1\n\t" -#else "cvttq/svm %2,%1\n\t" -#endif "cvtqt/m %1,%0\n\t" : "=f"(new_x), "=&f"(tmp1), "=&f"(tmp2) : "f"(new_x));
From: Aurelien Jarno <aurelien@aurel32.net> The alpha version of ceil wrongly return sNaN for sNaN input. Fix that by checking for NaN and by returning the input value added with itself in that case. Finally remove the code to handle inexact exception, ceil should never generate such an exception. Changelog: * sysdeps/alpha/fpu/s_ceil.c (__ceil): Add argument with itself when it is a NaN. [_IEEE_FP_INEXACT] Remove. * sysdeps/alpha/fpu/s_ceilf.c (__ceilf): Likewise. (cherry picked from commit 062e53c195b4a87754632c7d51254867247698b4) --- ChangeLog | 7 +++++++ sysdeps/alpha/fpu/s_ceil.c | 7 +++---- sysdeps/alpha/fpu/s_ceilf.c | 7 +++---- 3 files changed, 13 insertions(+), 8 deletions(-)