I see it support encoding T2 for Thumb-2 instruction set.But which instruction format does Cortex-R support for ARM instruction,encoding A1 orA2?
I think I should point out that A1 format is not a 12-bit constant. It is an 8 bit constant rotated around by a power of 0,2,4,..30 so that for instance
0x00057000 can be encoded
0x345 cannot be encoded
whereas for MOVW ( which will be used automatically if necessray)
0x00057000 cannot be encoded
0x345 can be encoded
You're absolutely right - thanks for pointing that out. 12-bit AREM constants are strange beasts!
They're very useful though. The Aarch64 also has a lot of strange but very useful constant encodings, a characteristic of the ISA that has thankfully been kept whatever about all the other simplifications.
Thank you for your help.