b$)(0\mathrm{.}5$ Point$)$ Please explain the functionality of the program $($i$.$e$.,$ what it does$),$ and give the updated data in the memory after the program execution in Table $4.$

Solution:

It's like a sort function$($like insertion sort$),$ sorting from small to large.

Table $4$: Updated Memory Content After Program Execution

$\backslash$table$[[$Address$,$Momory Content$],[$dots$,$dots,dots,dots,cdots,dots,dots,dots,dots$],[0\backslash$times $10010000,0\backslash$times $0000000=,0\backslash$times $0000000$b$,0\backslash$times $0000000$e$,0\backslash$times $0000000$E$,0\backslash$times $0000001$b$,0\backslash$times $0000001$e$,0\backslash$times $00000020,0\backslash$times $00000021],[0\backslash$times $10010020,0\backslash$times $00000011,0\backslash$times $00000022,0\backslash$times $00000033,0\backslash$times $00000044,0\backslash$times $00000055,0\backslash$times $00000066,0\backslash$times $00000077,0\backslash$times $00000088],[$dots$,$dots,dots,dots,cdots,dots,dots,dots,...$]]$

c$)(0\mathrm{.}5$ Point$)$ Are there any problem with this program? $($Hint: related to issues of register usage convention$).$

Solution:

Yes. We may affect the register values outside the function.

So we need to use local registers and stack space to ensure our uses do not affect the register values outside the function. $(2$ Points$)$ Table $2$ gives the RISC$-$V binary code and data $($both in hexadecimal representation$)$ for a program. Suppose $PC=000400000$ before program execution.

Table $2$: Memory Content Before Program Execution

$\backslash$table$[[$Address$,,,,$Momory,Content,,,$],[$cdots$,$cdots,cdots,cdots,cdots,...,cdots,cdots,$-],[0$x$00400000,0\backslash$times $0$Ee$10517,0\backslash$times $00050513,0\backslash$times $00800593,0$x$00$B$000$eE$,0$x$00008067,0$x$00450293,0$x$00259313,0$x$00650363],[0$x$00400020,0$x$0272$d$863,0$x$0002=303,0$xinfe$2$Be$13,0$xe$63,0$x$000$in$2$e$83,0$x$01435863,0$x$01$de$2223,0$xinfe$=0=13],[0$x$00400040,0$xlarr$=0006$e$3,0\backslash$times $006-$:$2223,0\backslash$times $00428293,0$xinetimes $00000$B$67,...,$dots,...$],[$cdots$,$cdots,cdots,cdots,...,...,cdots,cdots,cdots$],[0\backslash$times $10010000,0\backslash$times $0000001$e$,0\backslash$times $00000021,0\backslash$times $0000000$e$,0\backslash$times $0000000$b$,0\backslash$times $0000000$E$,0$x$00000020,0\backslash$times $0000001$b$,0\backslash$times $0000000=],[0\backslash$times $10010020,0\backslash$times $00000011,0\backslash$times $00000022,0\backslash$times $00000033,0\backslash$times $00000044,0\backslash$times $00000055,0$x$00000066,0\backslash$times $00000077,0\backslash$times $00000088],[$cdots$,$cdots,cdots,cdots,cdots,cdots,cdots,cdots,cdots$]]$

a$)(1$ Point$)$ Please translate the RISC$-$V binary code back into RISC$-$V assembly code in Table $3.$ The semantics of the first instruction AUIPC is: and here Imm$20=00fc10.$

Table $3$: Assembly Code of the Program

$\backslash$table$[[$Label$,$Instruction$],[$L$1$: $,,$AUIPC $\backslash$times $10,0\backslash$times $0$fc$10],[$L$2$:$,$ADDI x$10,$x$10,0],[$L$3$:$,$ADDI X$11,$ X$0,8],[$L$4$:$,$JAL x$1,$ L$6],[$L$5$:$,$JALR x$0,$x$1,0],[$L$6$:$,$ADDI x$5,$ X$10,4],[$L$7$:$,$SLLI x$6,$x$11,2],[$L$8$:$,$ADD x$7,$x$10,$x$6],[$L$9$:$,$BGE x$5,$x$7,$ L$21],[$L$10$:$,$LWx$6,0($x$5)],[$L$11$:$,$ADDI x$28,$x$5,-4],[$L$\mathrm{.}12$:$,$BLT x$28,$x$10,$ L$18],[$L$13$:$,$LW x$29,0($x$28)],[$L$14$:$,$BGE x$6,$x$29,$ L$18],[$L$15$:$,$SW x$29,4($x$28)],[$L$16$:$,$ADDI x$28,$x$28,-4],[$L$17$:$,$BEQ$\backslash$times $0,$x$0,$L$12],[$L$18$:$,$SW $\backslash$times $6,4(\backslash$times $28)],[$L$19$:$,$ADDI x$5,$x$5,4],[$L$\mathrm{.}20$:$,$BEQ$\backslash$times $0,$x$0,$L$9],[$L$21$:$,$JALR x$16,$x$0,0]]$