Bug 143279

Summary: x86_64 ecvt() returns "inf" for valid denormalized doubles
Product: Red Hat Enterprise Linux 3 Reporter: Jason Baietto <jason.baietto>
Component: glibcAssignee: Jakub Jelinek <jakub>
Status: CLOSED ERRATA QA Contact: Brian Brock <bbrock>
Severity: medium Docs Contact:
Priority: medium    
Version: 3.0CC: roland
Target Milestone: ---   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Fixed In Version: RHBA-2005-096 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2005-05-18 10:00:00 EDT Type: ---
Regression: --- Mount Type: ---
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Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Jason Baietto 2004-12-17 18:40:24 EST
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030922

Description of problem:
The x86_64 ecvt() function returns "inf" or "-inf" for valid
denormalized doubles.  The function works correctly on i686 systems
(same library version).  Both systems running RHEL3 update 2.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
Compile and run the following program on both i686 and x86_64 systems.

#include <stdio.h>
#include <stdlib.h>
#include <ieee754.h>

main() {
   char* s;
   int decpt, sign, ndigits=7;
   union ieee754_double D;
   D.ieee.exponent = 0; /* denormalized */
   D.ieee.negative = 0;
   D.ieee.mantissa0 = 0x0; /* MSB */
   D.ieee.mantissa1 = 0x1; /* LSB */
   printf("Input=%e\n", D.d);
   s = ecvt(D.d, ndigits, &decpt, &sign);
   printf("Output=%s, decpt=%d, sign=%d\n", s, decpt, sign);

Actual Results:  On an x86_64 system:

Output=inf, decpt=-309, sign=0

Expected Results:  On an i686 system:

Output=4940656, decpt=-323, sign=0

Additional info:
Comment 3 Jakub Jelinek 2004-12-23 04:51:39 EST
Fix queued for RHEL3 U5 and RHEL4 U1.
Comment 4 Jakub Jelinek 2004-12-23 16:15:26 EST
Fix added to glibc-2.3.2-95.31, for the time being available from
Comment 7 Tim Powers 2005-05-18 10:00:00 EDT
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.