From:	SMTP%"ARNE@ko.hhs.dk" 31-DEC-1994 12:56:30.04
To:	EVERHART
CC:	
Subj:	Re: Port VAX Macro to AXP

From: Arne Vajhoej <ARNE@ko.hhs.dk>
X-Newsgroups: comp.os.vms
Subject: Re: Port VAX Macro to AXP
Message-ID: <01HLAMPZRQCY8WXSGB@kopc.hhs.dk>
Date: Sat, 31 Dec 1994 13:34:51 +0100
Organization: Info-Vax<==>Comp.Os.Vms Gateway
X-Gateway-Source-Info: Mailing List
Lines: 88
To: Info-VAX@Mvb.Saic.Com

>      Several years back, the Macro subroutine F_FILE_ATTR.MAR was posted to
> INFOVAX as a convenient solution for people who wanted to use the features
> of the DCL lexical function F$FILE_ATTRIBUTES from within their FORTRAN or
> C programs.  It has done the job for me so far, but now I need to port my
> application to OpenVMS AXP.
> 
>      A quick attempt with the assembler on the Alpha indicates problems
> (diagnostics are listed below).  I don't know enough about the assembly
> language of either the VAX or AXP processors to be sure that I can solve the
> problems.  So, before I put time into the project, I'll ask:

It is 1 warning and 2 informationals ! The code is actual working !

>   1.  If you have ported F_FILE_ATTR.MAR for use on an ALPHA, would you
>       please post it to INFO_VAX or mail it to me?

It is simple to remove the "errors".

See below.

>      I've included the original F_FILE_ATTR.MAR as a VMS_SHARE structure at the
> end of this posting for anyone who may be interested in looking at the code.
> (All 3 files in the VMS_SHARE structure are included in this one message which
> I realize partially defeats the purpose of VMS_SHARE, but does make it easy for
> you to ignore this posting. :-) )

> L060:   CASEW   R9,#F_ALQ,#14                   ; Branch to appropriate code.
> ^
> %AMAC-W-TOOFEWCAS, too few CASE destinations found
> at line number 485 in file MYDISK:[DIRECTORY]F_FILE_ATTR.MAR;1

From the code fragment:

L060:	CASEW	R9,#F_ALQ,#14			; Branch to appropriate code.
ICODES:	.WORD	ALQ-ICODES			; The following codes all return
	.WORD	BKS-ICODES			; integer values.
	.WORD	BLS-ICODES
	.WORD	DEQ-ICODES
	.WORD	EOF-ICODES
	.WORD	FSZ-ICODES
	.WORD	GRP-ICODES
	.WORD	MBM-ICODES
	.WORD	MRN-ICODES
	.WORD	MRS-ICODES
	.WORD	NOA-ICODES
	.WORD	NOK-ICODES
	.WORD	PVN-ICODES
	.WORD	RVN-ICODES
	BRW	FAILURE			; Bad code.

Actually there is a programming bug here !  The VMS VAX assembler did
not find it, but the VMS AXP compiler did !

Change from:

L060:	CASEW	R9,#F_ALQ,#14			; Branch to appropriate code.

to:

L060:	CASEW	R9,#F_ALQ,#13			; Branch to appropriate code.

>         MOVQ            @4(AP),INP_LOG_NAM_D    ; Move input logical descriptor.
> ^
> %AMAC-I-MEMREFNOT, memory reference not naturally aligned in routine
> F_FILE_ATTRIBUTES
> at line number 440 in file MYDISK:[DIRECTORY]F_FILE_ATTR.MAR;1

> L080:   MOVQ            (R6),OUTBUF_DESC        ; Output is a string.  Get
> ^
> %AMAC-I-QUADMEMREF, quadword memory references may be unaligned in routine
> F_FILE_ATTRIBUTES
> at line number 514 in file MYDISK:[DIRECTORY]F_FILE_ATTR.MAR;1

You can ignore those two informationals or substitute each MOVQ with two
MOVL's !

The compilers is telling you, that it can not detremine whether the quadwords
being moved is proper aligned (quadword aligned) and if they are not, then
there may be a significant performance decrease. This is not relevant for
this routine !

                                                          Arne

Arne Vajhøj                             local DECNET:  KO::ARNE
Computer Department                     PSI:           PSI%238310013040::ARNE
Southern Denmark Business School        Internet:      ARNE@KO.HHS.DK
                WWW URL: http://www.hhs.dk/~arne/arne.html