Optimizing YourCompaq COBOL Program
15.1 Specifying Optimization on the Compiler Command Line
EV56—Generates code for some 21164 chip implementations that use the byte
and word manipulation instruction extensions of the Alpha architecture.
Programs compiled with the EV56 option may incur emulation overhead on
EV4 and EV5 processors, but will still run correctly on OpenVMS Version7.1
(or later) systems.
EV6—Generates code for the 21264 chip implementation that uses the
following extensions to the base Alpha instruction set: BWX (Byte/Word
manipulation) and MAX (Multimedia) instructions, square root and FIX
(Floating-point convert) instructions, and CIX (Count) instructions.
Programs compiled with the EV6 option may incur emulation overhead
on EV4, EV5, EV56, and PCA56 processors, but will still run correctly on
OpenVMS Version7.1 (or later) systems.
EV67—Generates code for the 21264A chip implementation that uses the
following extensions to the base Alpha instruction set: BWX (Byte/Word
manipulation) and MAX (Multimedia) instructions, square root and FIX
(Floating-point convert) instructions, and CIX (Count) instructions.
Programs compiled with the EV67 option may incur emulation overhead on
EV4, EV5, EV56, EV6, and PCA56 processors, but will still run correctly on
OpenVMS Version7.1 (or later) systems.
PCA56—Generates code for the 21164PC chip implementation that uses
the byte and word manipulation instruction extensions and multimedia
instruction extensions of the Alpha architecture.
Programs compiled with the PCA56 option may incur emulation overhead on
EV4, EV5, and EV56 processors, but still run correctly on OpenVMS Version
7.1 (or later) systems.
Note
If a program contains declarations of non-EXTERNAL variables that are
not referenced in the program, the Compaq COBOL compiler does not
allocate those variables. These variables are not affected by /OPTIMIZE;