optimization/6475: zlib miscompilation with gcc-3.1

[gbeauchesne@mandrakesoft.com]

>Number:         6475
>Category:       optimization
>Synopsis:       zlib miscompilation with gcc-3.1
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          wrong-code
>Submitter-Id:   net
>Arrival-Date:   Fri Apr 26 03:06:01 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     Gwenole Beauchesne
>Release:        3.1 20020425 (prerelease)
>Organization:
>Environment:
i586-mandrake-linux-gnu
>Description:
make test fails with a particular combination, and only that combination so far, of optimization flags.

CFLAGS="-O2 -frename-registers -fomit-frame-pointer -mcpu=pentiumpro -fPIC"
>How-To-Repeat:
I am sorry but I don't have a testcase at this point.

1) Get zlib-1.1.4 sources
2) Configure as follows: CFLAGS="-O2 -frename-registers -fomit-frame-pointer -mcpu=pentiumpro -fPIC" ./configure --shared
3) make; make test
>Fix:
Remove one (any of) the CFLAGS.
>Release-Note:
>Audit-Trail:
>Unformatted: