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Re: Fix pow (0.0, -Inf) (bug 14241)
On 06/15/2012 01:17 PM, Joseph S. Myers wrote:
On Fri, 15 Jun 2012, Andreas Jaeger wrote:
- if (ABS(y) > 1.0e20) return (y>0)?0:INF.x;
+ if (ABS(y) > 1.0e20) return (y>0)?0:1.0/ABS(x);
k = checkint(y);
if (k == -1)
return y < 0 ? 1.0/x : x;
Can't we just revert this - just using INF.x in both places? Why do we need
the division here?
When y is finite, the divide-by-zero exception is required, which means
the division must be executed. It's the case of infinite y where ideally
there would be no exception (as per the IEEE 754 semantics that
divide-by-zero exceptions are for exact infinities as results for
operations on *finite* operands) and C11 makes the exception optional.
thanks for the explanation. In that case your changes is fine.
Andreas
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