qtspim

问题 How can i change least significant bit in a register in Mips? In another post How to get LSB bit in MIPS? it saws how to get it but i want to change it. 回答1: The following one line should do it: xori $t0, $s0, 1 Explained: the contents in $s0 contains zeros and ones, while the immediate value has zeros and a one in the LSB. Whenever the LSB is 0, it is xored with 1 and outputs a 1. Whenever it is 1, it is xored with 1 and outputs a 0. The remaining bits will output a 1 if they are 1 and a 0

问题 The QtSPIM MIPS assembler already shows some lines of code even though there is no program loaded, like can be seen on https://ecs-network.serv.pacific.edu/ecpe-170/tutorials/qtspim-tutorial. I assume this is required for loading programs, but I would be very interested in an exact explanation to understand all details. 回答1: A QtSPIM program consists of two parts: an exception handler, and a user program. The default exception handler includes both a short user-mode startup code sequence

问题 The QtSPIM MIPS assembler already shows some lines of code even though there is no program loaded, like can be seen on https://ecs-network.serv.pacific.edu/ecpe-170/tutorials/qtspim-tutorial. I assume this is required for loading programs, but I would be very interested in an exact explanation to understand all details. 回答1: A QtSPIM program consists of two parts: an exception handler, and a user program. The default exception handler includes both a short user-mode startup code sequence

问题 My program is supposed to do the following: -Getting continiously an integer from the user (x), -printing the character at the x position in the string. -The program exits when the user inputs 0. .text .globl __start __start: li $s3,20 #string length start: li $v0,5 syscall move $s0,$a0 #integer now in $a0 beq $s0,$zero,exit li $s1,0 #counter is 0 la $s2,str #address of string now is $s2 loop:lbu $t1,0($s2) #choosing char of string addi $s1,1 #increment counter by 1 addi $s2,1 #next char beq

问题 I am absolutely brand new to assembly programming and am trying to implement the following function (in C) in MIPS: int main() { int A[5]; // Empty memory region for 5 elements int B[5] = {1,2,4,8,16}; int i; for(i=0; i<5; i++) { A[i] = B[i] - 1; } i--; while(i >= 0) { A[i]=(A[i]+B[i]) * 2; i--; } } So far what I have is this: main: #Register Map #i --> $s0 #A[0] --> $s1 address of start of A #B[0] --> $s2 address of start of B #A[i] --> $t0 #B[i] --> $t1 #(A[i] + B[i]) --> $t2 #((A[i] + B[i]

问题 I am absolutely brand new to assembly programming and am trying to implement the following function (in C) in MIPS: int main() { int A[5]; // Empty memory region for 5 elements int B[5] = {1,2,4,8,16}; int i; for(i=0; i<5; i++) { A[i] = B[i] - 1; } i--; while(i >= 0) { A[i]=(A[i]+B[i]) * 2; i--; } } So far what I have is this: main: #Register Map #i --> $s0 #A[0] --> $s1 address of start of A #B[0] --> $s2 address of start of B #A[i] --> $t0 #B[i] --> $t1 #(A[i] + B[i]) --> $t2 #((A[i] + B[i]

问题 I am absolutely brand new to assembly programming and am trying to implement the following function (in C) in MIPS: int main() { int A[5]; // Empty memory region for 5 elements int B[5] = {1,2,4,8,16}; int i; for(i=0; i<5; i++) { A[i] = B[i] - 1; } i--; while(i >= 0) { A[i]=(A[i]+B[i]) * 2; i--; } } So far what I have is this: main: #Register Map #i --> $s0 #A[0] --> $s1 address of start of A #B[0] --> $s2 address of start of B #A[i] --> $t0 #B[i] --> $t1 #(A[i] + B[i]) --> $t2 #((A[i] + B[i]

问题 I was able to (partly) successfully read in a file in MIPs. Below is my current code. In QtSpim, when I run it, I get a pointer to the file in $a1, but the last few characters of the file are repeated twice. The number of characters that is repeated changes depending on the file. From what I've seen, it seems to be linked to the number of new-line characters in the file unless the new-line chars are at the very end of the file (meaning, if there were 5 new-line characters, the last 5

问题 Whenever I run the following code: #counts length of a string .data .data string: .asciiz "Hello" printedMessage: .asciiz "The length of the string: " .text main: la $a0, string # Load address of string. jal strlen # Call strlen procedure. jal print addi $a1, $a0, 0 # Move address of string to $a1 addi $v1, $v0, 0 # Move length of string to $v1 addi $v0, $0, 11 # System call code for message. la $a0, printedMessage # Address of message. syscall addi $v0, $0, 10 # System call code for exit.

问题 Actually, my task is to multiply two 32bits number in MIPS which then generate the output of 64bits. Least significant 32bits are to be saved in 'lo' register and the remaining in 'hi' register to my understanding. When I multiply 100000 and 200000 I get a817c800 in 'lo' register and 4 in 'hi' register mult $t1, $t2 mflo $s0 mfhi $s1 回答1: When I multiply 100000 and 200000 I get a817c800 in 'lo' register and 4 in 'hi' register Correct. Because the result is 64 bits wide and you are using a 32