optimization/2076: scheduler ignores data dependency

[dje@watson.ibm.com]

>Number:         2076
>Category:       optimization
>Synopsis:       scheduler ignores data dependency
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Feb 23 14:46:00 PST 2001
>Closed-Date:
>Last-Modified:
>Originator:     dje@watson.ibm.com
>Release:        gcc-3.0 20010222 (prerelease)
>Organization:
>Environment:
rs6000-ibm-aix4.3.3.0
>Description:
c-torture/execute/980205.c demonstrates a bug where the
first scheduler pass moves a load of a parameter from the
stack argument area before the parameter has been spilled
to the argument area.  Compiler pass 980205.c.16.regmove
shows the arguments spilled to the argument area before
FP pseudo is loaded.  After the scheduling pass, the load
from the pseudo has been moved to the beginning of the
basic block before the argument area on the stack is valid.
>How-To-Repeat:

>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: