z/OS V1R9.0 UNIX System Services Command ... - Christian Grothoff

More inlining will improve application performance and increase application
memory usage. The z/OS XL C/C++ User’s Guide contains more
information on the INLINE compiler option.
Example: The following is an example of a compile with optimization with
no report generated, a threshold of 500 abstract code units, and a limit of
2500 abstract code units:
c89 -o outfile -O2 -Wc,’inline(auto,noreport,500,2500)’ file.c
When using IPA, the default is -O (level 1) optimization and inlining. IPA
optimization is independent from and can be specified in addition to this
optimization level. IPA is further described under the -W option on page 78.
If compiling with PDF, the same optimization level must be used in the
PDF1 and PDF2 steps.
If you compile your program to take advantage of dbx source-level
debugging and specify –g (see the -g option on page 72), you will always
get -0 (level zero) optimization regardless of which of these compiler
optimization levels you specify.
In addition to using optimization techniques, you may want to control
writable strings by using the #pragma strings(readonly) directive or the
ROSTRING compiler option. As of z/OS Version 1 Release 2, ROSTRING
is the default.
For more information on this topic, see reentrancy in z/OS XL C/C++ in
z/OS XL C/C++ Programming Guide or the description of the ROSTRING
option in the z/OS XL C/C++ User’s Guide.
-o outfile
Specifies the name of the c89/cc/c++ output file.
If the -o option is specified in addition to the –c option, and only one source
file is specified, then this option specifies the name of the output file
associated with the one source file. See file.o under “Operands” on page 81
for information on the default name of the output file.
Otherwise the -o option specifies the name of the executable file produced
during the link-editing phase. The default output file is a.out.
-p Ignored by cc. Provided for compatibility with historical implementations of
cc. Flagged as an error by c89 and c++.
-q Ignored by cc. Provided for compatibility with historical implementations of
cc. Flagged as an error by c89 and c++.
-r Specifies that c89/cc/c++ is to save relocation information about the object
files which are processed. When the output file (as specified on –o) is
created, it is not made an executable file. Instead, this output file can later
be used as input to c89/cc/c++. This can be used as an alternative to an
archive library.
IPA Usage Note:
c89, cc, and c++
When using -r and link-editing IPA compiled object files, you must link-edit
with IPA (see the description of IPA under the -W option). However, the -r
option is typically not useful when creating an IPA optimized program. This
is because link-editing with IPA requires that all of the program information
is available to the link editor (that is, all of the object files). It is not
Chapter 2. Shell command descriptions 75