Epson S5U1C63000A Conditional Assembly Instructions, <Name, <Name, #ifdef, [#else, #endif, [#else, #endif, #ifndef, Format 1), Format 2), Name definition, Instruction formats

CHAPTER 4: ASSEMBLER

4.7.5Conditional Assembly Instructions (#ifdef ... #else ... #endif, #ifndef... #else ... #endif)

A conditional assembly instruction determines whether assembling should be performed within the specified range, dependent on whether the specified name (Define name) is defined or not.

Instruction formats

Format 1)	#ifdef	<Name>
		<Statement string 1>
	[#else
		<Statement string 2> ]
	#endif

If the name is defined, <Statement string 1> will be subjected to the assembling.

If the name is not defined, and #else ... <Statement string 2> is described, then <Statement string 2> will be subjected to the assembling. #else ... <Statement string 2> can be omitted.

Format 2)	#ifndef	<Name>
		<Statement string 1>
	[#else
		<Statement string 2> ]
	#endif

If the name is not defined, <Statement string 1> will be subjected to the assembling.

If the name is defined, and #else ... <Statement string 2> is described, <Statement string 2> will be subjected to the assembling. #else ... <Statement string 2> can be omitted.

<Name>:

Conforms to the restrictions on Define name. (See #define.)

<Statement string>:

All statements, excluding conditional assembly instructions, can be described.

Sample description: #ifdef TYPE1

ld %x,0x12

#else

ld %x,0x13

#endif

#ifndef SMALL #define STACK1 0x31 #endif

Name definition

Name definition needs to have been completed by either of the following methods, prior to the execution of a conditional assembly instruction:

(1)Definition using the start-up option (-d) of the assembler.

Example: as63 -d TYPE1 sample.s

(2)Definition in the source file using the #define instruction.

Example: #define TYPE1

The #define statement is valid even in a file to be included, provided that it goes before the conditional assembly instruction that uses its Define name. A name defined after a conditional assembly instruction will be regarded as undefined.

When a name is going to be used only in conditional assembly, no substitute character string needs to be specified.

70	EPSON	S5U1C63000A MANUAL
		(S1C63 FAMILY ASSEMBLER PACKAGE)