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65 lines
1.8 KiB
Plaintext
65 lines
1.8 KiB
Plaintext
;
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; File: EndianAware.a
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;
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; Contains: macros for 68K clients that are aware of platform endian-ness
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;
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; Written by: Craig Prouse
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;
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; Copyright: © 1993 by Apple Computer, Inc., all rights reserved.
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;
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; Change History (most recent first):
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;
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; <1> 11/10/93 fau first checked in
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;
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;
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IF (&TYPE('__INCLUDINGENDIANAWARE__') = 'UNDEFINED') THEN
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__INCLUDINGENDIANAWARE__ SET 1
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IF &TYPE('littleEndian') = 'UNDEFINED' THEN
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littleEndian SET 1
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ENDIF
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; ……………………………………………………………………………………………………………………………………………………………………………………………………………………
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; ENDSW (pseudo-instruction)
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;
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; Operation: (Size = Byte) None
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; (Size = Word) Dn[8:15] <-> Dn[7:0]
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; (Size = Long) Dn[31:24] <-> Dn[7:0]; Dn[23:16] <-> Dn[15:8]
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;
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; Syntax: ENDSW Dn
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;
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; Attributes: Size = (Byte, Word, Long)
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;
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; Description: Exchange bytes within a word or longword to convert between
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; big-endian and little-endian representations.
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;
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; CCR: Undefined
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; ……………………………………………………………………………………………………………………………………………………………………………………………………………………
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MACRO
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ENDSW.&size &Dn
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IF &UC(&size) = 'L' OR &UC(&size) = 'W' OR &UC(&size) = 'B' OR &size = '' THEN
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IF littleEndian THEN
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IF &UC(&size) <> 'B' THEN
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rol.w #8,&Dn
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ENDIF ; Size <> Byte
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IF &UC(&size) = 'L' THEN
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swap &Dn
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rol.w #8,&Dn
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ENDIF ; Size = Long
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ENDIF ; littleEndian
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ELSE
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AERROR (&CONCAT('''',&UC(&size),''' is an invalid operand size for ENDSW'))
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ENDIF ; Size = B | W | L
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ENDM
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ENDIF ; __INCLUDINGENDIANAWARE__
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