1
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SLAC VM NOTEBOOK
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Module 24: SLAC Enhancements to and Beautifications of the IBM
H-Level Assembler for Version 2.8
-
Greg Mushial
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Revision 6
20 July 1983 (CMS ASMH Ver. 2.9)
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Module 24: The IBM Level H Assembler has
been modified to provide added language and
processing capabilities. This note
describes only the departures from the full
language, and assumes a working familiarity
with the Level H Assembler language.
-
SLAC Computing Services (SCS)
Stanford Linear Accelerator Center (SLAC)
Menlo Park, California 94025
1
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DISCLAIMER NOTICE
This document and/or portions of the material and data furnished
+ ___ ________ ___ ____ _________
herewith, was developed under sponsorship of the U.S.
+ ________
Government. Neither the U.S. nor the U.S.D.O.E., nor the Leland
Stanford Junior University, nor their employees, makes any
warranty, express or implied, or assumes any liability or
responsibility for accuracy, completeness or usefulness of any
information, apparatus, product or process disclosed, or
represents that its use will not infringe privately-owned
rights. Mention of any product, its manufacturer, or suppliers
shall not, nor is it intended to, imply approval, disapproval,
or fitness for any particular use. The U.S. and the University
at all times retain the right to use and disseminate same for
any purpose whatsoever.
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-
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Publishing History for Module 24
Revision 1.......14 Mar. 1979 (ASMH Ver. 2.4)
Revision 2........5 Nov. 1979 (ASMH Ver. 2.5)
Revision 3.......30 Aug. 1980 (ASMH Ver. 2.6)
Revision 4....3 Sep. 1981 (CMS ASMH Ver. 2.7)
Revision 5....9 Dec. 1982 (CMS ASMH Ver. 2.8)
Revision 6...20 July 1983 (CMS ASMH Ver. 2.9)
1 Revision 6 SLAC VM NOTEBOOK Page iii
Module 24: IBM H-Level Assembler
-
0 CONTENTS FOR MODULE 24
-
0 Chapter
+ _______
+ page
+ ____
0 1. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . 1
+ 1. INTRODUCTION 1
0 2. CHANGES TO THE ASSEMBLER . . . . . . . . . . . . . . . . . . 2
+ 2. CHANGES TO THE ASSEMBLER 2
0 Changes to Printed Output . . . . . . . . . . . . . . . . 2
Changes to Error Messages and Severities . . . . . . . . . 3
Changes to Input and Output Handling . . . . . . . . . . . 3
Changes to Parameters . . . . . . . . . . . . . . . . . . 5
0 3. CHANGES TO THE MACRO LANGUAGE . . . . . . . . . . . . . . . . 7
+ 3. CHANGES TO THE MACRO LANGUAGE 7
0 4. CHANGES TO THE ASSEMBLY LANGUAGE . . . . . . . . . . . . . . 9
+ 4. CHANGES TO THE ASSEMBLY LANGUAGE 9
- Appendix
+ ________
+ page
+ ____
0 A. THE CMS/ASMH INTERFACE AND ITS BEHAVIOR . . . . . . . . . . . 14
+ A. THE CMS/ASMH INTERFACE AND ITS BEHAVIOR 14
0 The Interface Function . . . . . . . . . . . . . . . . . . 14
ASMH Command Format . . . . . . . . . . . . . . . . . . . 14
ASMH Parameters Actually Understood by the Interface . 14
Alternate MACLIB Specification . . . . . . . . . . . . 15
- INDEX TO MODULE 24 . . . . . . . . . . . . . . . . . . . . . . . 16
+ INDEX TO MODULE 24 16
1 Revision 6 SLAC VM NOTEBOOK Page 1
Module 24: IBM H-Level Assembler
-
0 Chapter 1
+ Chapter 1
0 INTRODUCTION
+ INTRODUCTION
- The SLAC modifications to the IBM Program Product H-Level Assembler
are of three kinds:
0 Changes that do not affect the programming language, but enhance
the capabilities and usability of the Assembler;
0 Changes to the macro and conditional assembly language; and
0 Changes to the assembly ("open-code") language.
0 ¦ Note: Versions 2.7 and beyond are supported only in a VM/SP environ-
¦ ment (though Versions 2.7 through 2.9 are known to have successfully
¦ run at at least a couple of MVS and MVS/SP installations).
0 ¦ Note: Those parts of this document that changed with the current
¦ revision are denoted by "¦" in the left margin.
0 ¦ Note: The SLAC modifications, Versions 2.0 through 2.8 are/were
¦ based on IBM' Version 1 of ASMH; Versions 2.9 and beyond are/will be
based on IBM's Version 2.
1 Revision 6 SLAC VM NOTEBOOK Page 2
Module 24: IBM H-Level Assembler
-
0 Chapter 2
+ Chapter 2
0 CHANGES TO THE ASSEMBLER
+ CHANGES TO THE ASSEMBLER
-
2.1 CHANGES TO PRINTED OUTPUT
+ 2.1 CHANGES TO PRINTED OUTPUT
+ _______ __ _______ ______
0 ¦ The heading at the top of each page contains the identification
"(SLAC V2.9)".
0 A subset of the IEV9xx error messages that appear in the
SYSPRINT data set now will also appear in the SYSTERM data set
(e.g., no core left, i/o error...).
0 The default number of lines in SYSTERM for a no-error assembly is
now 2. The "ASSEMBLER DONE" and the "NO STATEMENTS FLAGGED" are
still printed, and the rest are suppressed.
0 The DECKID (the name field from the first title card) is now also
printed in SYSTERM. This is helpful if you have done a batched
assembly and are trying to determine which assembly is responsible
for an error message.
0 MACRO/Copy Code Source Cross-Reference. This is a list of the
SYSLIB data set names (in search order), and a listing of the mac-
ros and copy code that were used from each. The MACRO/Copy Code
Source Cross-Reference is under the control of the NO MSRC param-
eter. MSRC (the default) will allow it to be produced.
0 DSECT Cross-Reference. Directly after the MACRO/Copy Code
Source, if NODXREF is not specified (i.e., DXREF is the default),
a listing of the DSECTs in the assembly is produced. For each
DSECT, its name, length (in bytes), and the statement number where
it is defined are given.
0 At the top of each page, the current active USINGs are now printed
on up to two subtitle lines. These USINGs are current as of the
end of assembly of the last instruction on the prior page. These
lines are under the control of the NO UMAP parameter. UMAP (the
default) will cause the USINGs to be printed.
0 The second heading line on each page of the actual assembly list-
ing (the line with 'LOC OBJECT ADDR1 ADDR2') will start with
'D-LOC' if IBMOUT is not in effect and at the time of the page
eject the assembly was in a DSECT.
0 The IBM implementation of SYSTERM has been entirely replaced. The
new SYSTERM, for errors in macro-generated code, will only print
the macro call once. After printing any individual macro call, it
1 Revision 6 SLAC VM NOTEBOOK Page 3
Module 24: IBM H-Level Assembler
0 will only print the statement in error and its associated error
messages, rather than all the statements between the call to the
+ ___
error. The format for SYSTERM is now the same as that for
SYSPRINT (i.e., it's not all rearranged like the old SYSTERM).
0 At the end of each assembly listing, the number of utility file
(SYSUT1) reads and writes are displayed, along with the SYSIN,
SYSPRINT and SYSLIB counts which were displayed before.
0 ¦ The output produced as the Assembly Symbol Cross Reference (the
¦ cross-reference under the control of NO XREF option) has been
¦ modified to indicate which references to a symbol will result in
¦ that symbol being altered at execution time; such references are
denoted by being underscored.
-
2.2 CHANGES TO ERROR MESSAGES AND SEVERITIES
+ 2.2 CHANGES TO ERROR MESSAGES AND SEVERITIES
+ _______ __ _____ ________ ___ __________
0 A new error test and diagnostic message have been added:
0 IEV056 - USING RENDERED NULL BY A PRIOR ACTIVE USING
0 Given the rules governing base-displacement resolution of implied
addresses (choose the register giving the smallest displacement, and
the highest-numbered such register), this message will be issued if
it is found that a prior active USING's range overlaps and super-
sedes that of the USING being processed. The severity level of this
error is 4.
0 The error message "IEV044 - SYMBOL NOT DEFINED" has been extended
so that it now will tell you which symbol is thought to be unde-
fined.
0 A misquoted operand on a TITLE card now will only earn you a level
4 error.
-
2.3 CHANGES TO INPUT AND OUTPUT HANDLING
+ 2.3 CHANGES TO INPUT AND OUTPUT HANDLING
+ _______ __ _____ ___ ______ ________
0 ASMH will now accept WYLBUR pressed format (with RECFM=U) as input
for both SYSIN and SYSLIB. The concatenations of SYSLIB may be
either RECFM=FB or RECFM=U, or a mixture of the two. Another
change to SYSLIB processing is that the data set with the largest
block size need not be first in the SYSLIB concatenation sequence.
0 An exit is available just before each line is printed. The exit
routine name is specified by 'PEXIT=XXXX' in the invocation PARM
string. XXXX is the module name of the exit routine in the PDS
pointed to by the EXITLIB DD statement. The exit routine is
called using standard OS linkage conventions. The parameter
address list whose address is passed in R1 is:
1 Revision 6 SLAC VM NOTEBOOK Page 4
Module 24: IBM H-Level Assembler
0 A(the line to be printed)
A(the SYSPRINT DCB)
A(OCTL values)
A(line type flag byte)
0 The first two are self-explanatory. The OCTL values, 4 successive
halfwords, will be described below in the section "Changes to the
Assembly Language." The line type flag is a single byte whose bits
are defined as:
0 '80' - This line is part of the 3-line title
field at the top of each page.
'40' - This line is a machine instruction line.
'20' - This line is a DC/DS line.
'10' - This line is part of the symbol table
cross-reference.
'08' - This line is part of the post-assembly
messages.
'04' - This line is part of the pre-assembly
'02' - SYSPRINT DCB open exit entry (occurs just before
the exit returns to finish the open).
'01' - This line is the first output line of
this assembly.
0 (Note: For the open-exit call, only the DCB address and the flag
byte address are defined; any nonzero return code is equivalent
to 20.)
0 When the exit routine returns control to the Assembler, R15 must
contain a return code. If an invalid return code is returned,
the exit will be turned off (i.e., never called again for this
assembly). The valid return codes are:
0 0 - print the line in the buffer
4 - don't print the line in the buffer
8 - print the line and return back to the
exit with an empty buffer
12 - don't print the line and return with
an empty buffer
16 - final return for this line
20 - kill the exit (i.e., don't call again
for this assembly)
0 The LRECL of the SYSPRINT DCB has been unhardwired from 121. This
allows you to specify any value greater than or equal to 121. (If
the LRECL specified is less than 121 it will be set to 121.) If
you do specify a value larger than 121, only the first 121 bytes
of each print buffer will be properly blanked. It's up to you to
blank or clear anything beyond 121.
0 The DD name for the object deck output data set for the Loader or
Linkage Editor is now determined in much the same way as in ASMG.
The ASMH default DD name, SYSGO, can be overridden by an alternate
1 Revision 6 SLAC VM NOTEBOOK Page 5
Module 24: IBM H-Level Assembler
0 DD name list. This name is searched for in the TIOT; if it is
found, it will be used as the DD name. If not, the TIOT is
searched for SYSGO or SYSLIN. If either is there, the one found
will be used. If both are there, SYSGO will be used. If neither
is there, the DD name in the DCB will be left as is and processing
will continue as in the original ASMH. (The above does not apply
to ASMH under CMS).
0 SYM cards are now produced for equates whose first operand is
relocatable and the LOCTR for that operand is the current one.
The format is the same as that generated by ASMF.
0 For any part of ASMH's input that is a WYLBUR edit data set, one
now has a choice of formats of the sequence field. The invocation
parameter INTEGER, the default, will yield a sequence field of 8
decimal digits (Fortran I8 format). DECIMAL, the other choice,
will yield a sequence field of 4 digits, a period, and 3 more dig-
its (Fortran F8.3 format).
0 The input WYLBUR line number 234.567 will yield "00234567" with
INTEGER, and "234.567" with DECIMAL. Note that an input of
"87654.321" with the DECIMAL option yields: "7654.321" (the
sequence field only has room for 8 characters).
0 The FOLD parameter causes ASMH to treat all lower case characters
as their upper case counterparts. NOFOLD is the default.
-
2.4 CHANGES TO PARAMETERS
+ 2.4 CHANGES TO PARAMETERS
+ _______ __ __________
0 If you specify the REL2 invocation parameter (a new option),
2-byte A-type relocatable constants are allowed, as in AL2(*).
Y-type constants must still have absolute operands; only A-type
constants are affected by the REL2 parameter in this version of
ASMH.
0 The default for the RLD/NORLD invocation parameter is now NORLD.
0 The SYSPRINT exit parameter PEXIT=XXXX is described above, in the
discussion of changes to input and output handling.
0 The Assembler can now run entirely in memory, without SYSUT1. By
specifying NODISK, the Assembler will ignore SYSUT1 and attempt to
run entirely with internal buffering of information that normally
would be spilled to disk. If there isn't enough memory for the
assembly to be done this way, it will be terminated with a level
20 return code and a message.
0 At the end of each assembly, the Assembler will tell you how much
memory was allocated to buffers and what it determines it would
need to do the assembly completely in memory. This information is
provided even when you are not running with NODISK (i.e., DISK).
1 Revision 6 SLAC VM NOTEBOOK Page 6
Module 24: IBM H-Level Assembler
0 Two invocation parameters have been added to control PRINT
statements that appear within an assembly source. PRINTGEN, if
specified, will nullify any PRINT NOGENs embedded within a program
source. PRINTON does similarly, overriding PRINT OFFs.
0 The invocation parameter OPCNTS will cause the opcode table and
the opcode usage counts to be displayed at the end of each assem-
bly. The usage count displayed is the number of times the opcode
was searched for in the opcode table.
0 Within the Assembler, the opcodes are hashed onto a set of chains.
For the OPCNTS display, the beginning of each such chain is flag-
ged by a "¦".
0 The IBMOUT parameter requires the Assembler's SYSPRINT output to
be similar to that of the unmodified ASMH. At the current time,
IBMOUT really means NOUMAP, NOMSRC and NODXREF. If in the future
there are other options that would change the listing format,
IBMOUT will reset them also.
0 The parameters INTEGER/DECIMAL and FOLD/NOFOLD are described
above, in the discussion of changes to input and output handling.
0 The OLDTYPE invocation parameter is described below in the discus-
sion of changes to the macro language.
0 The parameter LIBMAC (NOLIBMAC is the default) has been added to
allow for the definition of each library resident macro to be
inserted into the SYSIN stream immediately preceeding the first
invocation of that macro.
0 ¦ With the introduction of ASMH release 2, (by definition) the
¦ assembler's opcode table was extended to include the XA opcodes.
¦ These new opcodes can cause conflicts with already existing user
¦ macros. For those users that wish to use the new assembler but
¦ cannot because opcode conflicts, the invocation parameter OPC370
¦ will delete the XA opcodes from the opcode table. The default
¦ option is OPCXA.
1 Revision 6 SLAC VM NOTEBOOK Page 7
Module 24: IBM H-Level Assembler
-
0 Chapter 3
+ Chapter 3
0 CHANGES TO THE MACRO LANGUAGE
+ CHANGES TO THE MACRO LANGUAGE
- Six new system variable symbols have been defined:
0 (1) &SYSSTYP - a character variable containing the location counter
type ('CSECT' or 'DSECT') at the invocation of the current
macro. (This definition is the same as in ASMG.)
0 (2,3) &SYSJOB, &SYSSTEP - both are character variables. For OS,
they return the job name and the rightmost non-blank stepname in
the TIOT. For CMS, they return 'NO JOB' and 'NO STEP' respec-
tively.
0 (4) &SYSNEST - an arithmetic type variable that returns the current
macro nesting level. Level 0 is defined as the open code level.
(The use of &SYSNEST makes writing recursive macros not only
easier but much safer. A recursive macro now has a way of tell-
ing how "deep in the weeds" it is, and can do something about
it.)
0 (5) &SYSMDSN - a character variable giving the source of the current
macro. The variable is 50 bytes long and is always padded with
blanks on the right. The first 6 bytes give the volume serial
on which the macro was found, and the following 44 bytes are the
data set name. For CMS, the DSN is only 8 bytes long and is the
file name.
0 (6) &SYSSTMT - an eight-byte character variable that contains the
statement number of the next statement to be generated. The
+ ____
variable is always eight characters and is padded on the left
with zeros. (The significant digits can be obtained by assign-
ing &SYSSTMT to an arithmetic-type variable.)
0 MACRO call statement name fields need not contain a valid Assem-
bler symbol. If you desire to put a number, any string without an
embedded blank, or any quoted string in the name field, no error
messages will be generated.
0 There are 2 valid operands on the AREAD statement that were not
documented by IBM: CLOCKB and CLOCKD. They return the result of
a TIME BIN and TIME DEC (in the OS sense) respectively.
0 The type attribute (T') of a parenthesized expression like "(10)"
is no longer 'N'. It is set to 'U' like it should be. The only
thing that has type attribute 'N' is a truly self-defining term.
(Try generating DC H'10E(10)' from within a macro because the
Assembler "told" you that the T' of "(10)" was 'N'. (For anyone
1 Revision 6 SLAC VM NOTEBOOK Page 8
Module 24: IBM H-Level Assembler
0 that may need the old definition, there is the OLDTYPE invocation
parameter.)
0 In LCLx/GBLx statements, the "&" preceding the variable names
being declared is no longer required. The absence of the "&" will
cause a level 0 warning message to be generated. This can be sup-
pressed by running ASMH with FLAG set to greater than 0.
0 The macro language has 2 new opcodes: ASPACE and AEJECT. They
provide services analogous to SPACE and EJECT, but only for the
listing of in-line macro source code. ASPACE, unlike its assembly
time counterpart, allows only an unsigned decimal integer as a
possible operand. AEJECT, like EJECT, neither requires nor allows
an operand.
1 Revision 6 SLAC VM NOTEBOOK Page 9
Module 24: IBM H-Level Assembler
-
0 Chapter 4
+ Chapter 4
0 CHANGES TO THE ASSEMBLY LANGUAGE
+ CHANGES TO THE ASSEMBLY LANGUAGE
- The MSOURCE operand may be specified on the PRINT statement.
If PRINT NOMSOURCE and PRINT GEN are both in effect, the body
(columns 1 - 71) of each macro-generated statement will not be
printed. If you write code rich in macro calls, it's nice to see
the addresses and the generated code on the left of the listing,
but the body of each statement can be fairly meaningless; hence
you may not want it printed.
0 The underscore (_) has been added to the list of characters that
ASMH allows in symbols. It is treated the same as a numeric digit
as far as where it may and may not appear in symbols and in opera-
tion codes and macro names. The common use is to separate words
in labels or identifiers (don't forget, ASMH allows identifiers of
up to 63 characters).
0 A new machine instruction operation code has been added for VM
users - DIAG (DIAGNOSE). DIAG is treated as an RS-type instruc-
tion:
0 DIAG r1,r3,d2(b2)
0 The Assembler instruction statement opcode OCTL provides a way of
passing parameters to the print exit. There are 4 operands
allowed on an OCTL statement, each of which must evaluate to a
16-bit absolute expression. These are evaluated and put into the
+ ________
corresponding halfwords of the OCTL values passed to the exit rou-
tine designated by the PEXIT parameter. Each operand may be of
three forms: an absolute expression; an expression of the form
* N (where * is taken to be the current value for that OCTL posi-
tion to which N is either added or subtracted); or null, which
means leave the current value as is. Note: The Assembler places
no meaning on the operand values; it simply evaluates them and
passes them to the print exit. For a missing (null) operand, the
value that was there before is left untouched.
0 A new operand, NOPRINT, has been added to the PUSH, POP, and PRINT
pseudo instructions. If you specify 'NOPRINT' the statement will
not be printed, as you would expect.
0 Qualified USINGs (or, more properly, Labeled USINGs and Qualified
Symbols), are a major new capability of ASMH, allowing much
greater control over the resolution of symbolic expressions into
base-displacement form with specific base registers.
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Module 24: IBM H-Level Assembler
0 The mechanics of this facility are rather simple. First, put a
label on a USING statement. Then, to force the Assembler to
resolve a symbol into base-displacement form through that USING,
qualify the symbol by preceding it with the label on the USING,
followed by a period. An example of Labeled USINGs and Qualified
Symbols would be:
0 PRIOR USING IHADCB,R10
NEXT USING IHADCB,R2
MVC PRIOR.DCBLRECL,NEXT.DCBLRECL
0 Without labeled USINGs, this would have to be written in the awk-
ward and inelegant form:
0 USING IHADCB,R10
MVC DCBLRECL,DCBLRECL-IHADCB(R2)
or
MVC DCBLRECL-IHADCB(,R10),DCBLRECL-IHADCB(R2)
0 Another example of the use of labeled USINGs is:
0 X CSECT
USING X,R10,R11
.
.
SYSUT2 USING IHADCB-(DCBUT2-X),R10,R11
LH R0,SYSUT2.DCBBLKSI
.
.
DCBUT2 DCB DDNAME=SYSUT2,...
0 The usual way of symbolically referencing parts of a DCB is to
load the address of the DCB into Rn followed by "USING IHADCB,Rn".
Such a technique requires you to allocate an extra register to
hold the address of the DCB. With labeled USINGs, you are able to
utilize already allocated registers (in this case, the program's
base registers). This technique works because the two USINGs do
not interfere with each other, even though they specify the same
registers; see below for details.
0 The label on a USING may not appear in the name field of any other
statements except that of other USINGs. If a label appears on a
USING, any other USING with the same label is nullified.
0 As is the case with non-labeled USING statements, a symbol (in the
first operand) or a register (in any of the remaining operands)
may appear in any number of USINGs. However, in the case of qual-
ified USINGs, as long as all the USINGs have unique labels, all
are considered active and are eligible to be used as qualifiers.
0 There is a very basic concept about Labeled and non-Labeled USINGs
that needs to be understood. In non-Labeled USINGs, a register
implies data, in the sense that a register may imply only one
1 Revision 6 SLAC VM NOTEBOOK Page 11
Module 24: IBM H-Level Assembler
0 piece of data at a time (i.e., when a register that appeared in a
USING appears in another USING, the prior USING is nullified). In
Labeled USINGs the reverse is true: the data implies a register.
That is, a single register may appear in multiple USINGs, all
+ ___
being active, so long as all the USINGs have unique labels. (Nul-
lification of Labeled USINGs occurs only when a repeated Label
appears, not when a repeated register appears.)
0 Labeled USINGs do not interfere with non-labeled USINGs. When the
Assembler resolves an implied address into base-displacement form,
either the expression to be resolved was qualified or not. If it
was, the specified labeled USING will be used. If not, the active
non-labeled USINGs will be scanned in the standard manner, looking
for a resolution.
0 A label on a USING defines an environment. As such, when you want
to nullify (delete) that environment, you must DROP the environ-
ment's name, the USING's label. An attempt to nullify a labeled
USING by dropping its registers will result in those registers
being dropped instead from the non-labeled USING pool. You would
nullify the Labeled USINGs from the example above by writing:
0 DROP PRIOR,NEXT
- Ten new extended branch mnemonics have been added to the existing
set. The new mnemonics are BGT, BGE, BEQ, BLE, BLT, and their
RR-type BCR counterparts BGTR, BGER, BEQR, BLER, and BLTR. The
corresponding branch mask digits are 2, 10, 8, 12, and 4 respec-
tively.
0 Literals and where they may appear has been made slightly less
restrictive. For machine instructions (and only machine instruc-
tions) a literal may appear anywhere a relocatable symbol is
valid. The exception to this is that the length attribute of a
literal is still undefined. An example of this might be:
0 LA R1,=C'??'-24 get parm for ADT lookup
0 AOPTION - a new opcode. Given that the invocation parameters
really only define a default assembly environment, AOPTION pro-
vides a means to specify a specific statement-by-statement assem-
bly environment. AOPTION may be used as many times as desired
during an assembly whether batched or not. (TEST and NOTEST are
currently the only valid operands.)
0 Now, at the end of each assembly, all the ASMH options are reset
to their invocation values. This means that an environment modi-
fied through AOPTION will not affect the next assembly in a batch.
0 The length attribute (L') used on a machine instruction within a
macro definition now behaves the same as that of ASM-F. (A state-
ment such as:
1 Revision 6 SLAC VM NOTEBOOK Page 12
Module 24: IBM H-Level Assembler
0 TM &X,L'&X
0 used to cause the Assembler to think that it had the letter "L"
followed by an improperly quoted string.)
0 Both the scale attribute (S') and the integer attributes (I') now
may also be used in open code. Both their definitions are identi-
cal to those for use within macro definitions.
0 Errors in the invocation parameters are diagnosed better. Instead
of getting a "There is an error in the parm list" message (at the
end of the assembly), the actual parms in error will be displayed.
In an OS environment, this display will be sent both to SYSPRINT
and to SYSTERM. (Note: In CMS, SYSTERM is assigned to the termi-
nal.)
0 More important, as soon as the assembler recognizes that it has an
erroneous parm, a warning message and the erroneous parm will be
sent to the terminal. (This way, if the parm is critical, the
assembly can be aborted before wasting a lot of time.)
0 Associated USING statements provide additional control over
address expression resolution. The format of an Associated USING
is:
0
