logarithm in rpgle

How a calculate  log base2 (X) (any value to log base 2 )  in rpgle ?
kishore murarisettyAsked:
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Gary PattersonVP Technology / Senior Consultant Commented:
You can call the log2 ILE CEE APIs: CEESSLG2 (single precision floating point value) or CEESDLG2 (double precision floating point)

See page 92 of the ILE CEE API Reference:  ftp://ftp.software.ibm.com/systems/power/docs/systemi/v5r4/en_US/ile.pdf

Untested, but should give you the basic idea.

ctl-Opt actgrp('TEST') option(*srcStmt: *noDebugIO);

dcl-Pr log2 extProc('CEESDLG2');
  input    float(8) const;
  output float(8);
  error    char(12) options(*omit);
end-Pr;

dcl-S x float(8) ;
dcl-S result float(8) ;

// Mainline
x = 8 ;
log2(x : result : *OMIT);
return;

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