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optimization/7908: ia64 warning 'Use of 'mov' may violate WAW dependency' on -O2 and above


>Number:         7908
>Category:       optimization
>Synopsis:       ia64 warning 'Use of 'mov' may violate WAW dependency' on -O2 and above
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Sep 13 06:46:01 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     Ben
>Release:        3.2
>Organization:
>Environment:
Compiling native code for a ia64 box
>Description:
The code sample is a fairly ugly routine to convert pointers
into a hex string. The code compiles fine with all levels of
optimisation. However, with -O2 and above, gcc reports the
following warning messages:

/tmp/cc2HCufe.s: Assembler messages:
/tmp/cc2HCufe.s:133: Warning: Use of 'mov' may violate WAW dependency 'GR%, % in 1 - 127' (impliedf), specific resource number is 14
/tmp/cc2HCufe.s:133: Warning: Only the first path encountering the conflict is reported
>How-To-Repeat:
Compile the code with -O2 or above. No other compile flags required.
>Fix:

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