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pseudo instructions

PostPosted: Sun Jan 11, 2009 7:32 pm
by ramachandran
what are the pseudo instructions available in assembler?

Re: pseudo instructions

PostPosted: Mon Jan 12, 2009 6:02 am
by William Thompson
ramachandran wrote:what are the pseudo instructions available in assembler?
I waited to see if anybody had any idea of what you meant by "pseudo instructions", but I guess everybody else is just a mystified as I am.......

Try again, are you referring to the "PLx" stuff the supervisor/nuclease is coded in? Or just macros?

Re: pseudo instructions

PostPosted: Mon Jan 12, 2009 7:45 am
by dick scherrer
Hello and welcome to the forum,

Might you mean macro instructions rather than pseudo?

Pseudo-code/instructions are often used to demonstrate logic so that something may explained rather than implemented in some specific instruction set.

Re: pseudo instructions

PostPosted: Wed Feb 18, 2009 8:41 pm
by hlasm1
EQU is an example of pseudo instruction in assembler. Pseudo instructions are never categorised as RR,RX,RS,SS1,SS2,Si instructions. Pseudo instructions do not occupy memory like A,AR and so on.

Re: pseudo instructions

PostPosted: Thu Feb 19, 2009 1:34 am
by dick scherrer
Hello and welcome to the forum,

I believe the term you are describing is a pseudo-operation:
A pseudo-operation, commonly called a pseudo-op, is an instruction to the assembler that does not generate any machine code. The assembler resolves pseudo-ops during assembly, unlike machine instructions, which are resolved only at runtime. Pseudo-ops are sometimes called assembler instructions, assembler operators, or assembler directives.


Additonal info is available here:
http://www.nersc.gov/vendor_docs/ibm/as ... _ovrvw.htm

Re: pseudo instructions

PostPosted: Thu Sep 16, 2010 9:39 am
by billyy2288
dick scherrer wrote:Hello and welcome to the forum,

I believe the term you are describing is a pseudo-operation:
A pseudo-operation, commonly called a pseudo-op, is an instruction to the assembler that does not generate any machine code. The assembler resolves pseudo-ops during assembly, unlike machine instructions, which are resolved only at runtime. Pseudo-ops are sometimes called assembler instructions, assembler operators, or assembler directives.


Additonal info is available here:
http://www.nersc.gov/vendor_docs/ibm/as ... _ovrvw.htm


Such a very amazing link!

Re: pseudo instructions

PostPosted: Thu Sep 16, 2010 10:48 am
by steve-myers
The HLASM Language Reference does not use either term "pseudo operation" or "pseudo instruction." I must admit I was surprised! HLASM calls them "assembler instructions," and defines several types. Taken as a generic, a "pseudo operation," "pseudo instruction, or "assembler instruction" refers to Assembler code that appear to be a machine code but serve other purposes. Many Assemblers have a REM pseudo instruction to define a comment, but HLASM does not define such an animal in the manual.
  • Program control - AINSERT, CNOP, COPY, END, EXITCTL, ICTL, ISEQ, LTORG, ORG, POP, PUNCH, PUSH, and REPRO.
  • Listing control - CEJECT, EJECT, PRINT, SPACE and TITLE.
  • Operation code definition - OPSYN
  • Program section and linking - ALIAS, AMODE, CATTR, COM, CSECT, CXD, DSECT, DXD, ENTRY, EXTERN, LOCTR, RMODE, RSECT, START, WXTRN and XATTR.
  • Base register - DROP and USING.
  • Data Definition - CCW, CCW0, CCW1, DC and DS.
  • Symbol definition - EQU.
  • Associated data - ADATA.
  • Assembler options - *PROCESS (Since *PROCESS starts in column 1, arguably it's not a pseudo instruction), ACONTROL.
I have to admit I've never used many of these; I'm just copying them from the HLASM Language Reference.