The execution environment

In this section:

• Introduction
• The execution environment
• The CODE/EDOC facility
• Mixing of Intel 32-bit Assembler and Fortran
• Labels
• Referencing Fortran variables
• Literals
• Halfword and byte forms of instructions
• Using the coprocessor
• Instruction prefixes
• Other assembler facilities
• Other machine-level facilities
• Error messages
• 64-bit assembler

Each process executes in its own 32-bit virtual address space. This gives 2 gigabytes for the combined code and data spaces (the remaining 2 gigabytes are reserved for the operating system). Using the advanced features of the CPU, each process address space is protected from modification by other processes executing within the system.