assignment 3

[brandon]

# Question templates

SFU ID: 301358970

Github username: bla118

Github: Link to github repo (your assignment repos are private so these links are only accessible to TAs and Instructor)

https://github.com/CMPT-295-SFU/assignment-3-bla118

Line and file: matmul.s, 68

Expected behavior:

Observed behavior: 

Question: I'm pretty sure I've done the dot function correct but I don't know why calling it in matmul.s creates an error later on. When I comment out the call, matmul proceeds and finishes as expected. Any help would be appreciated, thanks.

[Arrvindh Shriraman]

Please include comments in your assembly code

1) What are the input arguments to each method or routine

2) What is each register mapping

3) Include some C code to indicate what you are expecting the code to be doing

A figure would be helpful

That said --------------------------------------------------

Seems like you are violating the calling convention. t registers are caller save

Seems like you are using t registers in matmul for loop index. You also seem to be using t registers in dot.

Once the first call to dot happens, when it returns your matmul loop variables are in bad state. 

Two options

1) Use s registers for loop variables. save and restore within dot

OR 2) save and restore t registers across the call to dot on line 68: 

#jal ra, dot https://web.cecs.pdx.edu/~harry/riscv/RISCV-Summary.pdf (read page 153)

[brandon]

Thank you, I got it