English Amiga Board - View Single Post - I got fooled by address register word size operations

ross · 01 August 2021, 12:21

Is the source that is sign extended in Ax.w operations.

So this is like:

Code:

MOVE.L #$00AA0001,A0
MOVE.L #$00110002,A1
MOVE.W A1,A1
SUBA.L A1,A0

Yes, you could use MOVE.W Ax,Ax to sign extend Ax registers

This explain also the SUBA.W A2,A2

01 August 2021, 12:21	#2
ross Defendit numerus Join Date: Mar 2017 Location: Crossing the Rubicon Age: 54 Posts: 4,483	Is the source that is sign extended in Ax.w operations. So this is like: Code: MOVE.L #$00AA0001,A0 MOVE.L #$00110002,A1 MOVE.W A1,A1 SUBA.L A1,A0 Yes, you could use MOVE.W Ax,Ax to sign extend Ax registers This explain also the SUBA.W A2,A2