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Re: [PATCH] Update sparc ULPs.
From: "Joseph S. Myers" <joseph@codesourcery.com>
Date: Fri, 16 Nov 2012 17:40:10 +0000
> On Fri, 16 Nov 2012, David Miller wrote:
>
>> Failure: yn (10, min_value) == -inf: Exception "Underflow" set
>> Failure: yn (10, min_value) == -inf: Exception "Underflow" set
These two failures are indirectly caused by y0l/y1l, specifically
they lack the handling of extremely small values that the flt-32
and dbl-64 variants have.
So the code falls down into the multiply "X * X" and that's where we
get the underflow.
This should fix the same failures on powerpc too, since the
ldbl-128ibm files just include this code.
Any objections?
2012-11-17 David S. Miller <davem@davemloft.net>
* sysdeps/ieee754/ldbl-128/e_j0l.c ( __ieee754_y0l): Avoid
arithmetic underflow when absolute 'x' is very small.
* sysdeps/ieee754/ldbl-128/e_j1l.c (___ieee754_y1l): Likewise.
diff --git a/sysdeps/ieee754/ldbl-128/e_j0l.c b/sysdeps/ieee754/ldbl-128/e_j0l.c
index 112a8f3..7ee4731 100644
--- a/sysdeps/ieee754/ldbl-128/e_j0l.c
+++ b/sysdeps/ieee754/ldbl-128/e_j0l.c
@@ -831,6 +831,8 @@ long double
return -HUGE_VALL + x;
}
xx = fabsl (x);
+ if (xx < 0x2p-27)
+ return TWOOPI * __ieee754_logl (x);
if (xx <= 2.0L)
{
/* 0 <= x <= 2 */
diff --git a/sysdeps/ieee754/ldbl-128/e_j1l.c b/sysdeps/ieee754/ldbl-128/e_j1l.c
index 1f62bd0..4b10e97 100644
--- a/sysdeps/ieee754/ldbl-128/e_j1l.c
+++ b/sysdeps/ieee754/ldbl-128/e_j1l.c
@@ -838,6 +838,8 @@ __ieee754_y1l (long double x)
return -HUGE_VALL + x;
}
xx = fabsl (x);
+ if (xx < 0x2p-54)
+ return -TWOOPI / x;
if (xx <= 2.0L)
{
/* 0 <= x <= 2 */