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buzzybee · 31 May 2021, 01:02

Hi guys!

Wonder what you guys think of my code. Its purpose is to convert the value in register d7 to its absolute value:

Code:

	swap d7		; fetch x-acceleration
	tst.w d7	; test if negative
	smi d4		; Yes? Set d4
	ext.w d4	; create polarity converter
	eor d4,d7	; convert polarity (if x-acc is negative)

d7 is loaded with one longword-operation prior to this code, and contains x- (upper word) and y-acceleration (lower word) of a given sprite object. Code works. But this code is repeatedly executed a few times during one frame [in Reshoot Proxima 3], and I have a feeling that this can be optimized for speed. Any thoughts?

31 May 2021, 01:02	#1
buzzybee Registered User Join Date: Oct 2015 Location: Landsberg / Germany Posts: 526	Fast way of getting absolute value Hi guys! Wonder what you guys think of my code. Its purpose is to convert the value in register d7 to its absolute value: Code: swap d7 ; fetch x-acceleration tst.w d7 ; test if negative smi d4 ; Yes? Set d4 ext.w d4 ; create polarity converter eor d4,d7 ; convert polarity (if x-acc is negative) d7 is loaded with one longword-operation prior to this code, and contains x- (upper word) and y-acceleration (lower word) of a given sprite object. Code works. But this code is repeatedly executed a few times during one frame [in Reshoot Proxima 3], and I have a feeling that this can be optimized for speed. Any thoughts?