Arm Community
Site
Search
User
Site
Search
User
Support forums
Arm Development Studio forum
Doubt regarding working of a Neon instrcution
Jump...
Cancel
Locked
Locked
Replies
4 replies
Subscribers
119 subscribers
Views
2979 views
Users
0 members are here
Options
Share
More actions
Cancel
Related
How was your experience today?
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion
Doubt regarding working of a Neon instrcution
Vishwa Vishwa
over 12 years ago
Note: This was originally posted on 16th November 2009 at
http://forums.arm.com
hi,
Thanks in advance for any help.
vaddw.s8 q2,q3,d8
Accordin to the TRM, the 2nd operand is sign extended and then added with the corresponding elements in vector Q3.
While debugging in rvds, I am clear about
case i) +ve number in 2nd operand eg: 01020304
But I am not able to understand what is happening in the following case:
case ii) -ve number in 2nd operand eg: A0B0C0D0
pls take this eg:
q3 = 0x0001 0x0002 0x0003 0x0004
d8 = 0xA0B0C0D0
According to the explanation given in trm, the result I am expecting is 0xFFA1 0xFFB2 0xFFC3 0xFFD4. But this is not the case in debugger when the code is single stepped!
What should be the result?
Vishwa Vishwa
over 12 years ago
Note: This was originally posted on 16th November 2009 at
http://forums.arm.com
It is using simulator.....
Cancel
Vote up
0
Vote down
Cancel
Vishwa Vishwa
over 12 years ago
Note: This was originally posted on 18th November 2009 at
http://forums.arm.com
Yea....it is using Cortex-A8 ISSM simulator........
Cancel
Vote up
0
Vote down
Cancel
Simon Craske
over 12 years ago
Note: This was originally posted on 16th November 2009 at
http://forums.arm.com
Is this using a simulator or real hardware?
s.
Cancel
Vote up
0
Vote down
Cancel
Simon Craske
over 12 years ago
Note: This was originally posted on 16th November 2009 at
http://forums.arm.com
Which simulator? The A8 ISSM appears to generate the results you expect.
s.
Cancel
Vote up
0
Vote down
Cancel