Switch gets optimized away incorrectly

[Kevin O'Gorman]

A program stub with a very simple switch statement is performing incorrectly; examination of the assembler output shows that the switch has been partially optimized away, leaving only the default case, when a different case would be expected to execute.

This occurs in lucid (gcc-4.4) and natty (gcc-4.5.2), but I'm reporting it as a 4.4 bug because I mostly use lucid.

I expected the program to copy stdin to stdout, one character at a time. Instead, it fails on the first character, executing statements that I have in the default: case. These statements show that the switch expression should have chosen a different case, but that case is not even compiled into the assembler code.

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: gcc 4:4.4.3-1ubuntu1
ProcVersionSignature: Ubuntu 2.6.32-34.77-generic 2.6.32.44+drm33.19
Uname: Linux 2.6.32-34-generic i686
Architecture: i386
Date: Tue Oct 11 20:31:22 2011
InstallationMedia: Ubuntu 10.04.1 LTS "Lucid Lynx" - Release i386 (20100816.1)
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gcc-defaults

[dino99 (9d9)]

This version has expired some times ago, and no backport is expected as there is no 'security' reported problem