User guide

C-53
Compile-Time Options
platforms), generating intermediate assembly files (-gen_asm)
and then their parallel assembly, or generating intermediate C files
(-gen_c) and their parallel compilation.
-C
Stops after generating the C code intermediate files if you also
enter the -gen_c option, does not compile the C code files
(-gen_c is the default on IBM RS/6000 AIX). Use this option if
you want to compile by hand. This option can also be used with
the -gen_asm option for disabling assembly.
-O0
Suppresses optimization for faster compilation (but slower
simulation). Suppresses optimization both for how VCS writes
intermediate C code files and how VCS compiles these files. This
option is the uppercase letter "O" followed by a zero with no space
between them.
-Onumber
Specifies an optimization level for how VCS both writes and
compiles intermediate C code files. The number can be in the 0-4
range; 2 is the default, 0 and 1 decrease optimization, 3 and 4
increase optimization. This option is the uppercase letter "O"
followed by 0, 1, 2, 3 or 4 with no space between them. The -O0
variant has special mention above.
-override-cflags
Tells VCS not to pass its default options to the C compiler. VCS
has a number of C compiler options that it passes to the C compiler
by default. The options it passes depends on the platform, whether
it’s a 64 or 64-32 bit compilation and other factors. VCS passes
these options and then passes the options you specify with the
-CFLAGS compile-time option.