NOTE

Assembler Directives and Pseudo-Operations

.PROC and .PROCEND Directives

.PROC and .PROCEND Directives

The .PROC and .PROCEND directives bracket the instructions within a procedure.

Syntax

.PROC

Lines of Code

.PROCEND

Discussion

The .PROC directive signifies that the next instruction is the first instruction of a procedure. The .PROCEND directive signifies that the previous instruction was the last instruction of the procedure. Switching spaces or subspaces within a procedure is not permitted.

Every procedure must contain a .CALLINFO directive and normally contains an .ENTER and .LEAVE pseudo-operation. The only exception to the latter rule occurs in procedures that are either compiler-generated or created by programmers who are writing their own entry and exit code sequences. In this case, you must use the .ENTRY and .EXIT compiler directives.

Because the .ENTER and .LEAVE pseudo-operations guarantee that the stack unwind process works correctly, you should consistently use these directives rather than writing your own entry and exit code sequences.

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Chapter 4