* Re: [musl] [BUG] catanf: overflow when the parameter is valid
2020-02-05 13:32 ` Rich Felker
@ 2020-02-05 14:23 ` Rich Felker
0 siblings, 0 replies; 3+ messages in thread
From: Rich Felker @ 2020-02-05 14:23 UTC (permalink / raw)
To: sysysongyue; +Cc: musl
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On Wed, Feb 05, 2020 at 08:32:26AM -0500, Rich Felker wrote:
> On Wed, Feb 05, 2020 at 04:33:43PM +0800, sysysongyue@gmail.com wrote:
> > Hi!
> > I wrote some testcases for catanf(), and found that catanf(1+0*I) return
> > 99999996802856924650656260769173209088+99999996802856924650656260769173209088*I,
> > which should return pi/4 in expected. catanl, catanhf, and catanhl have
> > the same problem. Is this a bug? Any patches existed?
> > Thank you in advance!
>
> Looks like the equivalent of commit
> 10e4bd3780050e75b72aac5d85c31816419bb17d for catan was not applied to
> catanf. It should be an easy fix. I'll look at it.
>
> BTW your mail contained an empty plaintext part and the actual message
> was buried in the html version. I was able to dig it out to reply, but
> try to send text-only or at least with a matching text part since many
> readers probably can't see your email and the archive probably missed
> the body.
Proposed patch attached. It should be identical to the changes in
10e4bd3780050e75b72aac5d85c31816419bb17d except that it's applied to
catanf and catanl.
Rich
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diff --git a/src/complex/catanf.c b/src/complex/catanf.c
index e10d9c09..ef3907a5 100644
--- a/src/complex/catanf.c
+++ b/src/complex/catanf.c
@@ -87,29 +87,17 @@ float complex catanf(float complex z)
x = crealf(z);
y = cimagf(z);
- if ((x == 0.0f) && (y > 1.0f))
- goto ovrf;
-
x2 = x * x;
a = 1.0f - x2 - (y * y);
- if (a == 0.0f)
- goto ovrf;
t = 0.5f * atan2f(2.0f * x, a);
w = _redupif(t);
t = y - 1.0f;
a = x2 + (t * t);
- if (a == 0.0f)
- goto ovrf;
t = y + 1.0f;
a = (x2 + (t * t))/a;
- w = w + (0.25f * logf (a)) * I;
- return w;
-
-ovrf:
- // FIXME
- w = MAXNUMF + MAXNUMF * I;
+ w = CMPLXF(w, 0.25f * logf(a));
return w;
}
diff --git a/src/complex/catanl.c b/src/complex/catanl.c
index a9fc02db..e62526c0 100644
--- a/src/complex/catanl.c
+++ b/src/complex/catanl.c
@@ -97,30 +97,18 @@ long double complex catanl(long double complex z)
x = creall(z);
y = cimagl(z);
- if ((x == 0.0L) && (y > 1.0L))
- goto ovrf;
-
x2 = x * x;
a = 1.0L - x2 - (y * y);
- if (a == 0.0L)
- goto ovrf;
t = atan2l(2.0L * x, a) * 0.5L;
w = redupil(t);
t = y - 1.0L;
a = x2 + (t * t);
- if (a == 0.0L)
- goto ovrf;
t = y + 1.0L;
a = (x2 + (t * t)) / a;
- w = w + (0.25L * logl(a)) * I;
- return w;
-
-ovrf:
- // FIXME
- w = LDBL_MAX + LDBL_MAX * I;
+ w = CMPLXF(w, 0.25L * logl(a));
return w;
}
#endif
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