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IV35855: SLOWER PERFORMANCE FROM MISSED OPPORTUNITY IN A LOOP OPTIMIZIATI ON

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APAR status

  • Closed as program error.

Error description

  • Error Message: N/A
.
Stack Trace: N/A
.
Around 5% on 32-bit (running on Intel Tigerton E7330 servers)
and 10% on 64-bit (running on Intel Westmere X5670s) is observed
between 601 SR4 and 601 SR1

Local fix

  • N/A

Problem summary

  • The JIT compiler did not fully unroll a double nested loop in a
certain situations, resulting in slower performance.

Problem conclusion

  • This defect will be fixed in:
6.0.1 SR5
7.0.0 SR4
.
The JIT compiler is fixed to correctly unroll the loop to meet
the JTC performance criteria

Temporary fix

  • 



Comments


    

  • 



APAR Information




    

  • APAR number
    IV35855
    • 

  • Reported component name
    JIT
    • 

  • Reported component ID
    620700124
    • 

  • Reported release
    260
    • 

  • Status
    CLOSED  PER
    • 

  • PE
    NoPE
    • 

  • HIPER
    NoHIPER
    • 

  • Special Attention
    NoSpecatt
    • 

  • Submitted date
    2013-01-24
    • 

  • Closed date
    2013-01-24
    • 

  • Last modified date
    2013-01-24
    • 





    

  • APAR is sysrouted FROM one or more of the following:
    

    • 

  • APAR is sysrouted TO one or more of the following:
    

    • 



Fix information


    

  • Fixed component name
    JIT
    • 

  • Fixed component ID
    620700124
    • 



Applicable component levels


    

  • R260  PSY
       UP
    • 








      
              
                            

              

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Document Information


            

            


                        

            Modified date:
            

            24 January 2013
            

            
                      

        


        

        


      

    

  



    

  

  
    
            

          
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