Question

I have this C program that calculates an input and converts it to a BMI calculation. Any idea how this would look as an LC3 program? I'm taking an LC3 programming class next semester and want an idea of what this code would even translate to, just trying to get a head start. I'm more so curious on how to get user input in a LC3 program, then I can try myself and figure it out from there.

int main()
{
    double wt_lb, ht_in, bmi, ht_ft;

    printf("Please enter your weight in whole pounds: ");
    scanf("%lf", &wt_lb);
    printf("Please enter your height in whole inches: ");
    scanf("%lf", &ht_in);

    ht_ft = ht_in/12;
    bmi = (703*wt_lb)/(ht_ft*ht_ft);

    if (bmi < 18.5) {
            printf("You have a BMI of %.lf, and your weight status is underweight\n" &bmi);
    } else if (bmi >= 18.5 && bmi < 25) {
        printf("You have a BMI of %.lf, and your weight status is normal\n", &bmi);
    } else {
        printf("You have a BMI of %.lf, and your weight status is overweight\n", &bmi);
    }
}

Answer 1

[Start] Program ; num_X .FILL #0 num_Y .FILL #0 num_temp .FILL #0 ContProgram JSR ClearRegisters JSR ClearOutputArray AND R0, R0, #0 ST R0, num_R ; Get first number LEA R0, prompt1 PUTS JSR ReadInput LD R1, num_temp ST R1, num_X ; reset temp variable AND R0, R0, #0 ST R0, num_temp ; Get second number LEA R0, prompt2 PUTS JSR ReadInput LD R2, num_temp ST R2, num_Y AND R0, R0, #0 ST R0, num_temp ; prompt for operator LEA R0, prompt3 PUTS ; get operator GETC ; Character is stored in R0 OUT AND R6, R6, #0 LD R1, num_X LD R2, num_Y LEA R5, codesArray ; load codesArray address LDR R3, R5, #0 ; loads first symbol from R7 into R3 ADD R4, R0, R3 ; add contents of R0 (user input) and R3 BRz Addition LDR R3, R5, #1 ADD R4, R0, R3 BRz Subtract LDR R3, R5, #2 ADD R4, R0, R3 BRz Multiply LDR R3, R5, #3 ADD R4, R0, R3 BRz DivisionF OpComplete LEA R0, result1 PUTS ADD R6, R6, #0 Brn printNeg ST R6, num_R JSR DetermineSize JSR NumToASCII LEA R0, outputArray PUTS LEA R0, endStrg PUTS GETC OUT LD R5, minus30 ADD R0, R0, R5 Brz ContProgram ; End of program HALT num_R .FILL #0 prompt1 .STRINGZ "\nInput first number: " prompt2 .STRINGZ "\nInput second number: " prompt3 .STRINGZ "\nInput operation (+, -, *, /): " result1 .STRINGZ "\nResult = " endStrg .STRINGZ "\nContinue? Yes = 0, No = 1: " codesArray .FILL #-43 ; '+' .FILL #-45 ; '-' .FILL #-42 ; '*' .FILL #-47 ; '/' ;--------- Subroutines Start ---------; ; R1 <- X ; R2 <- Y ; R6 <- result of X (operation) Y ; Use R3, R4, & R5 for extra stuff ; ------------------------------ ; ReadInput ST R7, saveR7 LEA R3, inputArray ; R3 <- pointer to inputArray AND R4, R4, #0 ; init R4 to 0 AND R5, R5, #0 ; init R5 to 0 LoopReadInput GETC ADD R6, R0, #-10 ; check for return key BRz DoneReadInput OUT ; print character to screen STR R0, R3, #0 ; store char into inputArray ADD R4, R4, #1 ; inc++ size value ST R4, inputSize ; store R4 into inputSize variable ADD R3, R3, #1 ; inc++ array index ADD R5, R4, #-4 ; stop when 4 char long BRn LoopReadInput ; loop back for next character DoneReadInput LEA R3, inputArray ; R3 <- pointer to inputArray LEA R4, constArray ; R4 <- pointer to constArray LD R5, minus30 ; R5 <- contains hex 30 LD R6, inputSize ; R6 <- contains length of input ADD R6, R6, #-1 ; length - 1 LoopReadInput2 LDR R1, R3, #0 ; load ASCII digit from inputArray ADD R1, R1, R5 ; R1 <- contains integer ADD R2, R4, R6 ; R2 <- contins address of constant LDR R2, R2, #0 ; R2 <- load the number from the arrary JSR ReadInputExpand ; R1 <- Integer, R2 <- Constant LD R1, num_R ; Load mult result into R1 LD R0, num_temp ; Load the current num into R0 ADD R0, R0, R1 ; Add together ST R0, num_temp ; Store the sum back into the temp num ADD R3, R3, #1 ; increment pointer in inputArray ADD R6, R6, #-1 ; decrement size BRzp LoopReadInput2 ; loop back and continue to multiply out LD R7, saveR7 RET minus30 .FILL x-30 inputArray .BLKW #5 ReadInputExpand ST R6, saveR6 ST R4, saveR4 AND R6, R6, #0 AND R4, R4, #0 ADD R4, R4, R2 ; duplicate R2 so it remains unchanged Mult ADD R6, R6, R1 ADD R4, R4, #-1 BRp Mult ST R6, num_R LD R4, saveR4 LD R6, saveR6 RET NumToASCII ; prints number in R1 ST R7, saveR7 LD R3, outputSize ; load size into R3 LEA R6, outputArray ; load address of output into R6 Convert_Loop LEA R5, constArray ; load address of constArray -> R5 ADD R3, R3, #-1 ; decrement size of num ADD R5, R5, R3 ; R5 <- R5 + R3 LDR R2, R5, #0 ; load const from constArray at index R5 LD R1, num_R ; load the number into R1 ST R3, saveR3 ST R4, saveR4 ST R5, saveR5 ST R6, saveR6 JSR Division ; divide LD R3, saveR3 LD R4, saveR4 LD R5, saveR5 LD R6, saveR6 LD R0, convert_quot ; load quotient into R0 LD R5, num_remainder ; load remainder into R5 LD R4, plus30 ; load ASCII converter into R4 ADD R0, R0, R4 ; Convert quotient into ASCII STR R0, R6, #0 ; store R0 (ASCII) into index at R6 ADD R6, R6, #1 ; increment index at R6 ADD R3, R3, #0 ; break on R3 (size) ST R5, num_R BRp Convert_Loop ADD R0, R0, #0 ST R0, outputSize LD R7, saveR7 RET plus30 .FILL x30 Addition ADD R6, R2, R1 JSR OpComplete Subtract NOT R2, R2 ADD R2, R2, #1 ADD R6, R1, R2 JSR OpComplete Multiply AND R6, R6, #0 ; Quotient AND R3, R3, #0 ; init Y ADD R3, R2, #0 ; add Y to R3 Mul ADD R6, R6, R1 ADD R3, R3, #-1 Brp Mul JSR OpComplete DivisionF JSR Division JSR OpComplete Division AND R3, R3, #0 ; init R3 ADD R3, R1, #0 ; add X to R3 AND R4, R4, #0 ; init Y ADD R4, R2, #0 ; add Y to R4 AND R6, R6, #0 ; Quotient NOT R4, R4 ADD R4, R4, #1 ; Invert R4 Div ADD R3, R3, R4 ; X = X - Y BRn EndDiv ADD R6, R6, #1 ST R3, num_remainder Br Div EndDiv ST R6, convert_quot ; special case RET printNeg ST R7, saveR7 NOT R6, R6 ADD R6, R6, #1 LEA R0, negSym PUTS LD R7, saveR7 RET negSym .STRINGZ "-" outputArray .BLKW #5 DetermineSize ST R7, saveR7 LD R1, num_R ; store R6 (number) into R1 LEA R3, constArray AND R4, R4, #0 ; R4 is going to be index ADD R4, R4, #4 DetermineSizeLoop ADD R2, R3, R4 ; contains value from constArray LDR R2, R2, #0 ST R4, saveR4 ST R3, saveR3 JSR Division ; divide Result and Const LD R4, saveR4 LD R3, saveR3 ADD R6, R6, #0 ; make R6 relative BRp SizeDetermined ; if positive, we found size! ADD R4, R4, #-1 ; else decrement index BRnzp DetermineSizeLoop ; try again SizeDetermined ADD R4, R4, #1 ; size = index + 1 ST R4, outputSize LD R7, saveR7 RET outputSize .FILL #0 outputQuot .FILL #0 ClearRegisters AND R1, R1, #0 AND R2, R2, #0 AND R3, R3, #0 AND R4, R4, #0 AND R5, R5, #0 AND R6, R6, #0 RET ClearOutputArray LEA R0, outputArray LD R2, size5 ClearLoop AND R1, R1, #0 STR R1, R0, #0 ADD R0, R0, #1 ADD R2, R2, #-1 BRp ClearLoop RET size5 .FILL #5 constArray .FILL #1 .FILL #10 .FILL #100 .FILL #1000 .FILL #10000 num_remainder .FILL #0 inputSize .FILL #0 convert_quot .FILL #0 minus99 .FILL #-99 minus999 .FILL #-999 minus9999 .FILL #-9999 saveR3 .FILL #0 saveR4 .FILL #0 saveR5 .FILL #0 saveR6 .FILL #0 saveR7 .FILL #0 ; [End] Program ; .END