Bug 164805 - gcc -Os generates bad assembler code
Summary: gcc -Os generates bad assembler code
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 4
Classification: Red Hat
Component: gcc
Version: 4.0
Hardware: i386
OS: Linux
medium
medium
Target Milestone: ---
: ---
Assignee: Jakub Jelinek
QA Contact:
URL:
Whiteboard:
Depends On: 154116
Blocks: 156322
TreeView+ depends on / blocked
 
Reported: 2005-08-01 16:04 UTC by Elena Zannoni
Modified: 2007-11-30 22:07 UTC (History)
0 users

Fixed In Version: RHBA-2005-677
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2005-10-05 11:18:10 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2005:677 0 qe-ready SHIPPED_LIVE gcc bug fix update 2005-10-05 04:00:00 UTC

Description Elena Zannoni 2005-08-01 16:04:38 UTC
+++ This bug was initially created as a clone of Bug #154116 +++

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.6) Gecko/20050323
Firefox/1.0.2 Fedora/1.0.2-1.3.1

Description of problem:
For the included example, gcc generates assembler code that makes the assembler
complain.  The assembler code uses an immediate value in a movb that does not
fit in a byte.  The original C code does not do this.

Version-Release number of selected component (if applicable):
gcc-3.4.2-6.fc3

How reproducible:
Always

Steps to Reproduce:
1. fetch attached file "gcc-inline-bad-byte.c"
2. gcc -Os -c gcc-inline-bad-byte.c
  

Actual Results:  /tmp/ccDdmcnm.s: Assembler messages:
/tmp/ccDdmcnm.s:9: Warning: 277 shortened to 21


Expected Results:  no error messages

Additional info:

This example is boiled down from driver code being developed by the ivtv project.
Without inlining, there is no bad assembler code (I presume that the resulting
code is correct, but I have not looked).

Comment 1 Tom Kincaid 2005-08-02 11:06:08 UTC
QE-ACK

Comment 2 Red Hat Bugzilla 2005-10-05 11:18:10 UTC
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.

http://rhn.redhat.com/errata/RHBA-2005-677.html



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