Lyn,
You are right about the length of the instructions as defined by the ISAs.  
However, within gem5 we use a few extra bits in the upper 32 bits to indicate 
what ISA mode we’re in, i.e. v7, Thumb, v8, etc. since it is possible to switch 
between them.


Curtis

From: gem5-users [mailto:[email protected]] On Behalf Of liyinnan
Sent: Wednesday, June 24, 2015 8:21 PM
To: gem5-users
Subject: [gem5-users] Arm Instruction length in Gem5

Hi all,
    I am adding some instructions to the ARM ISA in Gem5 and I found that the 
data pass to the ARM decoder function is 64 bit long, my understanding is that 
both AARCH64 and AARCH32 instructions are 32 bit long, so dose anyone know 
where and why Gem5 increase the instruction length?

Thanks,
Lyn


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