Help/Support Registers (IDA PRO)

[Archipunchi 1 iPhone 8 Plus 13.4.1]

There is one question that torments me as soon as I go to practice in the disassembler, in each game or application there are different registers in the function (R/S/W/X), I don't understand if there is a difference between them? are they just coefficients in front of numbers ?, for example R7/W0 etc. or does each of these letters have some meaning? I am a resident of Russia and, unfortunately, I cannot find sensible textbooks on Ida, and foreign textbooks are too difficult for me for linguistic reasons. Help me understand these registers. THX

[Zahir 393.3k iPad Mini 4 13.6]

Don't @ me for the meanings or what they are used for but those R/S/W/X are just registers but they have their own purpose and ofcourse size difference

For example RX is for armv7 (32-bit arch)

MOV R0, R7 is you move whatever is in R7 to R0
ADD R0, R1, R2 is you take registers R1 and R2 and add them together and store the result inside R0

Writing ARM Assembly (Part 1) | Azeria Labs (azeria-labs.com)

 

W/X used in arm64 (64-bit), the difference I noticed is in the space it can hold as stated here

So you can interchange between W/X depending on what you are storing, like long long you should use X since it goes beyond 32-bits

MOV X0, X7, same as above
ADD X0, X1, X2, same as above

 

Coming to S/D , those are for floats/doubles. Both the arm32 and 64 have them but the syntax is a little different

FMOV S0, S1, store S1 inside S0
FADD D0, D0, D1, add D0+D1 and result inside D0

You can learn about them here: Learn the architecture: AArch64 Instruction Set Architecture (arm.com)