Texas Instruments TMS320C3x - Manual (Page 492)

Individual Instructions
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13.6.2 Optional Assembler Syntax
The assembler allows a relaxed syntax form for some instructions. These
optional forms simplify the assembly language so that special-case syntax
can be ignored. A list of the optional syntax forms follows.
- You can omit the destination register on unary arithmetic and logical oper-
ations when the same register is used as a source. For example,
ABSI R0,R0 can be written as ABSI R0
Instructions affected: ABSI, ABSF, FIX, FLOAT, NEGB, NEGF, NEGI,
NORM, NOT, RND
- You can write all 3-operand instructions without the 3. For example,
ADDI3 R0,R1,R2 can be written as ADDI R0,R1,R2
Instructions affected: ADDC3, ADDF3, ADDI3, AND3, ANDN3, ASH3,
LSH3, MPYF3, MPYI3, OR3, SUBB3, SUBF3, SUBI3, XOR3
This also applies to all of the pertinent parallel instructions.
- You can write all 3-operand comparison instructions without the 3. For
example,
CMPI3 R0,*AR0 can be written as CMPI R0,*AR0
Instructions affected: CMPI3, CMPF3, TSTB3
- Indirect operands with an explicit 0 displacement are allowed. In 3-operand
or parallel instructions, operands with 0 displacement are automatically
converted to no-displacement mode. For example:
LDI *+AR0(0),R1 is legal.
Also
ADDI3 *+AR0(0),R1,R2 is equivalent to ADDI3 *AR0,R1,R2
- You can write indirect operands with no displacement, in which case a
displacement of 1 is assumed. For example,
LDI *AR0++(1),R0 can be written as LDI *AR0++,R0
- All conditional instructions accept the suffix U to indicate unconditional
operation. Also, you can omit the U from unconditional short branch
instructions. For example:
BU label can be written as B label
- You can write labels with or without a trailing colon. For example:
label0: NOP
label1 NOP
label2: label assembles to next source line