Structured Control Macros; Structured Control Expressions - Texas Instruments TI-89 Software Manual

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3.8.2.

Structured Control Macros

The structured control macro facility provided by asm68k is a set of high-level
language constructs, which are used to generate run-time loops and conditional
execution. These macros expand into the appropriate assembly code to perform
the desired control structure. Since these macros are implemented efficiently,
they improve readability without sacrificing the desirable aspects of using
assembly language. The remainder of this section describes their usage.
Note: Structured control macros do not provide assembly-time control — they provide run-time
3.8.2.1.

Structured Control Expressions

Structured control expressions are used to specify the flow of execution for
certain structured control macros. These expressions are translated into one or
more CMP, BRA, and Bcc instructions to provide the necessary flow of control.
The expressions themselves have a logical value of true of false. They are used
with the IF, UNTIL, and WHILE directives. The syntax for constructing structured
control expressions is as follows:
Syntax
I. < cc1 > [ logical_op [. size ] < cc2 >]
II. < cc1 > [ logical_op [. size ] op3 < cc2 > op4 ]
III. op1 < cc1 > op2 [ logical_op [. size ] < cc2 >]
IV. op1 < cc1 > op2 [ logical_op [. size ] op3 < cc2 > op4 ]
Description
cc1
cc2
op1
op2
op3
op4
logical_op
TI-89 / TI-92 Plus Sierra C Assembler Reference Manual
control.
Specifies one of the integer conditional tests shown in Table 3.30.
Floating-point and PMMU conditional tests are not supported. The angle
brackets that enclose the conditional test are required characters.
Specifies an effective address expression (see section 3.5 Effective
Addressing Modes).
Specifies one of the following logical operators:
AND Logical AND
OR Logical OR
Section 3: Assembler
Not for Distribution Beta Version February 2, 2001