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.TH ACK 1 "$Revision$"
.ad
.SH NAME
ack \- Amsterdam Compiler Kit
.SH SYNOPSIS
\fBack\fP arguments
.br
\fBacc\fP arguments
.br
\fBapc\fP arguments
.br
\fBabc\fP arguments
.br
\fBm2\fP arguments
.br
\fBocm\fP arguments
.br
\fBf2c\fP arguments
.br
\fImachine\fP arguments
.SH DESCRIPTION
This program transforms sources in several
languages to load files for a variety of machines,
internally using several phases.
The transformation can be stopped at any phase.
Combining sources from several languages is allowed.
The run-time system of the first language mentioned,
either in the program call name or in the arguments,
is automatically included.
The libraries of all other languages mentioned,
containing most of the run-time systems,
are also automatically included.
Two types of load files can be distinguished,
\fIa.out\fP files containing machine code and \fIe.out\fP
files containing virtual EM machine code.
The last type is designed for interpretation; it is obtained by calling
the compiler as \fIem22\fP, \fIem24\fP, or \fIem44\fP.
Compilation time for interpretation is fast and gives many
runtime checks,
but execution with \fIem\fP(1) is about seven times slower.
Execution with \fIint\fP(1) is even slower than that, but available on
more machines.
Which combinations of languages and machines are allowed varies
in time and depends on the installation.
.PP
The actions of \fIack\fP are to repeatedly transform files with a
particular suffix into files with another suffix,
finally combining the results into a single file.
.PP
Different machines can use different suffices,
but the following are recognized by most machines:
.IP .p
Pascal program.
.IP .c
C module.
.IP .b
Basic program.
.IP .ocm
Occam program.
.IP .mod
Modula-2 module.
.IP .f
Fortran module.
.IP .e
EM assembly module in human readable form.
.IP .k
Compact EM assembly code.
.IP .m
Optimized compact EM assembly code.
.IP .s
Machine assembly language code.
.IP .o
Object file.
.PP
\fIAck\fP accepts the following flags:
.SB machine used
.IP \-m\fImachine\fP
This flag tells \fIack\fP to generate a load file for \fImachine\fP.
\fIMachine\fP can also be used as the program call
name, instead of \fIack\fP.
e.g. \fIack \-mi86 file.p\fP is equivalent to \fIi86
file.p\fP.
.SB output files
.IP \-o
Use the next argument as the name of the resulting file.
\fIAck\fP produces \fIa.out\fP or \fIe.out\fP by default.
This flag can always be used when \fIack\fP produces a single output file,
as in
.br
.ti +5
\fBack -c.s main.c -o new.s\fP.
.br
The output is produced on \fInew.s\fP instead of \fImain.s\fP.
.IP \-c\fI.suffix\fP
.IP \-c
\fIAck\fP tries to transform each source into a file with the \fIsuffix\fP.
When no \fIsuffix\fP is specified \fIack\fP stops just
before the phase where it combines all arguments into a load file,
thereby transforming the sources into \fI.k\fP, \fI.s\fP,
\&\fI.o\fP or \fI.m\fP files.
One extra \fIsuffix\fP is recognized here, \fI.i\fP,
this tells \fIack\fP to only preprocess all human readable sources,
producing files with \fIsuffix\fP \fI.i\fP.
.br
Note: \fIack\fP refuses to overwrite argument \fI.e\fP files.
.IP \-t
Preserve all intermediate files.
If two \fB\-t\fP are used,
\fIack\fP also preserves core dumps and output of failed transformations.
.SB messages
.IP \-w
Suppress all warning messages.
.IP \-v
Verbose.
Print information while juggling with files.
.IP \-KR
Tell the C-compiler to conform to "Kernighan & Ritchie" C.
.IP \-ansi
Tell \fIack\fP to use the ANSI C compiler instead of the old one.
.IP \-fp
Use the software floating point package, if present.
.SB preprocessing
.IP \-I\fIdir\fP
\&\`#include\' files whose names do not begin with \`/\' are
always sought first in the directory of the \fIfile\fP argument,
then in the directories named in \fB\-I\fP options,
then in directories on a standard list.
.IP \-D\fIname=def\fP
.IP \-D\fIname\fP
Define the \fIname\fP to the preprocessor,
as if by \`#define\'.
If no definition is given the \fIname\fP is defined as 1.
.IP \-U\fIname\fP
Remove any initial definition of \fIname\fP, before
preprocessing.
.IP \-P
Don't generate line directives.
.IP \-C
Leave C-comments in.
.SB debugging
.IP \-p
This flag tells both the Pascal and C front ends to include
code enabling the user to do some monitoring/debugging.
Each time a routine is entered the routine \fBprocentry\fP
is called and just before each return \fBprocexit\fP is called.
These routines are supplied with one parameter, a pointer
to a string containing the name of the routine.
.SB optimizing
.IP \-O
.IP \-O\fInum\fP
.IP \-O\fIopt1,opt2,...\fP
Try to use the named optimizers, or, if no optimizers are given,
try to use the optimizers with optimization level <= \fInum\fP (default 1).
For optimizer names, see the table at the end of this manual page.
Currently, only the global optimizer has a level > 1.
Higher levels will invoke more passes of the global optimizer.
For the global optimizer, it is also possible to indicate explicitly which
phases must be executed, using the following flags:
.RS
.IP \-EGO-IL
Inline substitution.
.IP \-EGO-CS
Common subexpression elimination.
.IP \-EGO-SR
Strength reduction.
.IP \-EGO-UD
Use definition analysis.
.IP \-EGO-LV
Live variable analysis.
.IP \-EGO-RA
Register allocation.
.IP \-EGO-SP
Stack pollution.
.IP \-EGO-BO
Branch optimization.
.IP \-EGO-CJ
Cross jumping.
.RE
.IP ""
Also, the following flags may be used:
.RS
.IP \-s<num>
Give an indication to the inline substitution phase,
how much bigger the program may get,
in percentage. This is only used as a rough indication.
The inline substitution phase will not make the program bigger when given \-s0.
.IP \-a
Indicate to the inline substitution phase that it is offered the whole program.
This allows it to throw away routines that it has substituted inline.
.IP \-Q
Give some statistics.
.IP \-T
Optimize for time.
.IP \-S
Optimize for size.
.RE
.IP ""
In principle, the optimization phases can be run in any order; a phase
may even be run more than once. However, the following rules must be obeyed:
.RS
.IP -
the Live Variable analysis phase (LV) must be run prior to the
Register Allocation phase (SA), as SA uses information produced by LV.
.IP -
SA should be the last phase.
.RE
.IP ""
Also, the following may be of use:
.RS
.IP -
Inline Substitution (IL) may create new opportunities for most other phases,
so it should be run as early as possible.
.IP -
Use Definition analysis (UD) may introduce opportunities for LV.
.IP -
Strength Reduction (SR) may create opportunities for UD.
.RE
.IP ""
The global optimizer is a combiner, so it should be offered all the source
files of the program. This is not strictly necessary, but it makes the
global optimizer more effective.
The current default optimization phases are:
.RS
.IP -
for \-O2: CJ, BO, SP;
.IP -
for \-O3: CS, SR, CJ, BO, SP, UD, LV, RA;
.IP -
for \-O4: IL, CS, SR, CJ, BO, SP, UD, LV, RA;
.IP -
for higher levels: as for \-O4.
.RE
.IP \-L
Disable the generation of code by the front ends to
record line number and source file name at run-time.
(This is the default for C and Fortran).
.SB libraries
.IP \-l\fIname\fP
Tells \fIack\fP to insert a library module at this point.
For example: the library \fImon\fP contains the
routines for systems calls needed by both C and Pascal.
.IP \-.\fIsuffix\fP
When linking multiple \fI.o\fP or \fI.m\fP files created by
separate calls of \fIack\fP together, \fIack\fP cannot deduce
the run-time system needed,
unless called as \fIapc\fP, \fIabc\fP, \fIocm\fP, \fIm2\fP, \fIf2c\fP, or \fIacc\fP.
This flag serves to tell \fIack\fP which runtime system is
needed in such a case.
For example: "ack \-c x.c ; ack \-.c x.o".
.IP \-r.\fIsuffix\fP
Most frontends and backends use one or
more run-time libraries.
These flags tell \fIack\fP to include the libraries needed when
a file with \fIsuffix\fP would be included in the arguments.
.IP \-LIB
This flag tells the peephole optimizer
.RF em_opt 6
to add information about the visibility of the names used
to each output module.
This is needed by
assembler/linkers when these modules are to be inserted
in libraries.
.SB interpreter
.IP \-{xxx}
The string starting after \`{\' and terminated by a \`}\' is passed
as an option string to the Pascal compiler and supersedes corresponding
options given in the source file.
See the ACK reference manual [4] for a list of options.
.IP "\-+xxx, \-\-xxx"
When interpreting programs, these flags are used to select some
options during interpretation, like test, profile, flow, extra and count.
A short description of these flags follows:
.RS
.IP "  t(est)" 12
test for undefined, overflow, array bound etc.
.IP "  f(low)"
keep track of executed source lines.
.IP "  c(ount)"
count the number of times a source line is executed.
.IP "  p(rofile)"
count the memory cycles executed per source line.
.RE
.IP "" 5
Test is on by default, the others are off. Normally, these
flag options are given each time the interpreter is run.
The EM assembler/linker offers the opportunity to change
the defaults per program.
The changed options are recorded in the "e.out" header.
These flags \-\- and \-+ are passed to the assembler for this purpose.
So, \-\-t and \-+pfce invert the defaults.
.SB general
.IP \-R\fIprogram=xxx\fP
Replace the \fIprogram\fP by the pathname \fIxxx\fP.
The program names referred to later in this manual are allowed here.
.IP \-R\fIprogram\-xxx\fP
The flag argument \fI\-xxx\fP is given to \fIprogram\fP.
.IP \-R\fIprogram:n\fP
Set the priority of the indicated transformation to \fIn\fP.
The default priority is 0, setting it to -1 makes it highly
unlikely the the phase will be used, setting it to 1 makes
it very likely that the phase will be used.
.IP \-k
Do not stop when an error occurs, but try to transform all
other arguments as far as possible.
.IP \-g
Instruct the front-end and back-end to produce symbolic debugger information
for \fIgrind\fP(1). This is currently supported by the following front-ends:
C, ANSI-C, Pascal, Modula-2, and the following back-ends: Motorola M68020,
Sparc, Vax, Intel 80386.
.IP \-gdb
Instruct the front-end and back-end to produce symbolic debugger information
for \fIgdb\fP. This is currently supported by the following front-ends:
C, ANSI-C, Pascal, Modula-2, and the following back-ends: Motorola M68020,
Sparc, Vax, Intel 80386.
.PP
All arguments without a suffix or with an unrecognized suffix
are passed to the loaders, as for flags.
.SH PREPROCESSOR
All C source programs are run through the preprocessor
before they are fed to the compiler proper.
On larger machines, the compiler has a built in preprocessor.
Other human readable sources (Modula-2, Pascal, or Basic programs and
machine assembly) are only preprocessed when they start with a \`#\'.
.PP
\fIAck\fP adds a few macro definitions when it calls the
preprocessor.
These macro\'s contain the word- and pointer-size and the sizes
of some basic types used by the Pascal, Basic and/or C compiler.
All sizes are in bytes.
.sp 1
.TS
tab(:);
l l l l.
EM_WSIZE:wordsize:EM_PSIZE:pointer size
EM_SSIZE:size of shorts (C):EM_LSIZE:size of longs (C+Pascal)
EM_FSIZE:size of floats (C):EM_DSIZE:size of doubles (C+Pascal)
.TE
.sp 1
The name of the \fImachine\fP or something like it when
the machine name is numeric is also defined (as 1).
As the ANSI C rules forbid this, in ANSI C, underscores are prepended to
these names.
.PP
The default directories searched for include files differ for each machine.
.SH PROGRAMS
\fIAck\fP uses one or more programs in each phase of the
transformation.
The table below gives the names \fIack\fP uses for these
programs.
Internally \fIack\fP maintains a mapping of these names to pathnames
for load files.
The table specifies which type of files are accepted by each
program as input and the file type produced as output.
.sp 1
.in +2
.TS
tab(:);
l l l l.
input:name:output:description
\&.f:f77:.c:Fortran-to-C front end
\&.c:cem:.k:C front end [4,5,6]
\&.p:pc:.k:Pascal front end [2,3,6]
\&.b:abc:.k:Basic front end [6,8]
\&.ocm:ocm:.k:Occam front end [9]
\&.mod:m2:.k:Modula-2 front end [11]
\&.e:encode:.k:Compactify EM assembly language [1]
\&.k:opt:.m:EM peephole optimizer
\&.k .m:decode:.e:Produce human readable EM assembly
\&.k .m:emass:e.out:Linker producing EM machine code [1]
\&.m:ego:.gk:EM global optimizer [10]
\&.gk:opt2:.g:Second EM peephole optimizer
\&.m .g:be:.s:backend
\&.s:asopt:.so:target optimizer
\&.s .so:asld:.out:Assembler/linker, Ack object format
\&.s .so:as:.o:Assembler, relocatable object
\&.o:ld:a.out:Linker, machine a.out format
\&.o:led:.out:Linker, Ack object format
\&.o:cv:a.out:Conversion from Ack object to machine object
.TE
.in -2
.SH "ENVIRONMENT VARIABLES"
.IP ACKDIR
If set, this environment variable overrides ack's idea of its home
directory.
.IP ACKM
If set, this environment variable overrides ack's idea of the default
machine it compiles for.
.IP ACKFE
If set, this environment variable tells ack where to get the front-end
description file.
.SH "SEE ALSO"
.PD 0
em_opt(6), em_ass(6), em_cg(6), ack.out(5)
.IP [1]
A.S. Tanenbaum, Hans van Staveren, Ed Keizer and Johan
Stevenson, \fIDescription of a machine architecture for use with
block structured languages\fP, Informatica rapport IR-81.
.IP [2]
K. Jensen and N. Wirth,
\fIPASCAL, User manual and report\fP Springer Verlag.
.IP [3]
The ISO Pascal standard proposal ISO/TC97/SC5-N462.
.IP [4]
B.W. Kernighan and D.M. Ritchie, \fIThe C Programming
language\fP, Prentice-Hall, 1978
.IP [5]
D.M. Ritchie, \fI C Reference Manual\fP
.IP [6]
Amsterdam Compiler Kit, reference manuals and UNIX manual pages.
.IP [7]
E.G. Keizer, Ack description file reference manual.
.IP [8]
M.L. Kersten a.o., \fIThe ABC compiler\fP.
.IP [9]
Kees Bot and Edwin Scheffer, \fIAn Occam Compiler\fP, IM-6.
.IP [10]
H.E. Bal, \fIThe design and implementation of the EM Global Optimizer\fP,
Informatica rapport IR-99.
.IP [11]
C.J.H. Jacobs, \fIThe ACK Modula-2 Compiler\fP.
.PD
.SH DIAGNOSTICS
.PD
The diagnostics are intended to be self\-explanatory.
.SH BUGS
Not all warning messages are superseded by \fB\-w\fP.
.br
Argument assembly files are not preprocessed when fed into the
universal assembler/loader.
.SH AUTHOR
Ed Keizer, Vrije Universiteit, Amsterdam
