Bug 10404

Summary:	strtod of very small number returns with errno set to ERANGE
Product:	glibc	Reporter:	Orion Poplawski <orion>
Component:	libc	Assignee:	Ulrich Drepper <drepper.fsp>
Status:	RESOLVED INVALID
Severity:	normal	CC:	glibc-bugs
Priority:	P2	Flags:	fweimer: security-
Version:	2.10
Target Milestone:	---
Host:		Target:
Build:		Last reconfirmed:

Description Orion Poplawski 2009-07-16 20:16:10 UTC

strtod (and atof) of "5.30498947741318e-315" returns 5.3049894774131808e-315 but
with errno set to ERANGE.  This is new in 2.10.1 compared to 2.9 and does not
appear to be correct.

Comment 1 Ulrich Drepper 2009-07-16 20:30:27 UTC

That's the correct behavior.

Comment 2 Orion Poplawski 2009-07-16 21:21:47 UTC

I guess it depends on what you think "cannot be represented, without
extraordinary roundoff error" (definition of underflow from the C99 standard
[7.12.1.5]) means.  5.3049894774131808e-315 compared to 5.30498947741318e-315
does not appear to me to have "extraordinary roundoff error".  I would suggest
that something other than a simple comparison with 2.2250738585072014E-308 for
triggering ERANGE is in order.