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CROSS ASSEMBLER->Assembler Source Code Format->Opcode Extensions
Many of the M68020 executable instructions may take a size extension (.B, .W and .L) as follows:
|.B||byte size |
|.W||word size |
|.L||long word size |
If a size extension is required and none is given, then .W is assumed by default.
Many of the 68881 instructions may also take an extension specifying the operand data format. These are:
|.B||byte integer format|
|.W||word integer format|
|.L||long word integer format|
|.S||single precision real data format|
|.D||double precision real data format|
|.X||extended precision real data format|
|.P||packed BCD real data format|
There is no specific default strategy for these format extensions.
The pseudo-ops DC and DS may also carry these 68881 format extensions. (.W is the default extension).
M68020 branch instructions default to word branch length and may take a .S extension to force a short branch or a .L extension to force a long branch. M68881 branch instructions also default to word branch length and make take a .L extension to force a long branch.
All of these extensions may be either upper or lower case and must be appended to the instruction mnemonic with no intermediate spaces.