Arm Development Studio forum CMP vc EORS

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CMP vc EORS

Etienne SOBOLE over 11 years ago

Note: This was originally posted on 28th June 2011 at http://forums.arm.com

Can anybody explain me why this code


cmp r0, r1
bne  .exit

is not equivalent to


eors r2, r0, r1
bne  .exit

except that r2 is changed of course !!!

Is the Z flag set when the destination register value is 0 ?

Etienne SOBOLE over 11 years ago

Note: This was originally posted on 28th June 2011 at http://forums.arm.com

Ok.
For the second time in a week, I was wrong and finally found my problem...

sorry, the 2 codes are equivalent.
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Simon Craske over 11 years ago

Note: This was originally posted on 28th June 2011 at http://forums.arm.com

Strictly speaking if you care about the N, C and V flags they're not.

CMP =~ SUBS CMN =~ ADDS TST =~ ANDS TEQ =~ EORS

hth
s.
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Etienne SOBOLE over 11 years ago

Note: This was originally posted on 29th June 2011 at http://forums.arm.com

Strictly speaking if you care about the N, C and V flags they're not.

Yes.
It was exactly my problem...

After my BNE instruction to exit from my loop
I had used 2 instructions

MOVLT and MOVGE and of course, the problem was here !!!
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