Chapter 40.VAX Dependent Features40.1. VAX Command-Line OptionsThe Vax version of as accepts any of the following options, gives a warning message that the optionwas ignored and proceeds. These options are for compatibility with scripts designed for other people’sassemblers.-D (Debug)-S (Symbol Table)-T (Token Trace)These are obsolete options used to debug old assemblers.-d (Displacement size for JUMPs)This option expects a number following the -d. Like options that expect filenames, the numbermay immediately follow the -d (old standard) or constitute the whole of the command lineargument that follows -d (gnu standard).-V (Virtualize Interpass Temporary File)Some other assemblers use a temporary file. This option commanded them to keep the informa-tion in active memory rather than in a disk file. as always does this, so this option is redundant.-J (JUMPify Longer Branches)Many 32-bit computers permit a variety of branch instructions to do the same job. Some of theseinstructions are short (and fast) but have a limited range; others are long (and slow) but canbranch anywhere in virtual memory. Often there are 3 flavors of branch: short, medium and long.Some other assemblers would emit short and medium branches, unless told by this option to emitshort and long branches.-t (Temporary File Directory)Some other assemblers may use a temporary file, and this option takes a filename being thedirectory to site the temporary file. Since as does not use a temporary disk file, this optionmakes no difference. -t needs exactly one filename.The Vax version of the assembler accepts additional options when compiled for VMS:-h nExternal symbol or section (used for global variables) names are not case sensitive on VAX/VMSand always mapped to upper case. This is contrary to the C language definition which explicitlydistinguishes upper and lower case. To implement a standard conforming C compiler, namesmust be changed (mapped) to preserve the case information. The default mapping is to convertall lower case characters to uppercase and adding an underscore followed by a 6 digit hex value,representing a 24 digit binary value. The one digits in the binary value represent which charactersare uppercase in the original symbol name.
