Hello, all.
In my calculation, i need to change sign of the odd elements of sInt16
vector, i.e. take the original
vSInt16 v // containing s0, s1, s2, s3, s4, s5, s6, s7,
and convert in into
vSInt16 v_inverted // containing s0, -s1, s2, -s3, s4, -s5, s6, -s7
I am using such vector to perform msum later.
Currenty i am using three instruction approach, using two additional
pre-created vector.
It is something like this:
where v_One16 is vSInt16 containing 1 in each element, and maskIm is
vSInt16 containging ( 0x0000, 0xFFFF, 0x0000, 0xFFFF, 0x0000, 0xFFFF,
0x0000, 0xFFFF );
First step is to get one's complement
Second is to add one (thus changing sign to all elements)
Third is select even element from original vector and odd from inverted
Could this be done using less instructions or less addidional registers?
Thank you.
