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PowerPC extensions for IBM AS400

Looking for an explanation or documentation on the as400 specific
extensions to the PowerPC instruction set.

Pointers on the as400 are stored as 16 byte values.  The LQ ( load
quad word ) and STQ ( store quad word ) instructions are used to load
and store those pointers.

Here is PPC assembler code that loads a pointer from an EA into a
register:
  LQ     24, 0x1e50(30), 6
  SELRI  26, 25, 0, 41

LQ loads the 16 bytes stored at EA reg30 + 0x1e50 into reg24 and
reg25.  The next SELRI stmt does something to reg25 and places the
result in reg26.  Does anyone know what the 3rd operand does in the LQ
instruction?  What the SELRI instruction does?

This site is the best I have been able to come up with. 
http://www.nersc.gov/vendor_docs/ibm/asm/lq.htm#lq_instruction
It documents LQ but does not explain what the 3rd operand is used for.

thanks,

-Steve Richter
0
srichter
10/31/2004 5:11:08 PM
comp.sys.powerpc.tech 819 articles. 1 followers. Post Follow

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