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[MIPS Assembly/ en] fixing line length

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Some lines were greater than 80 characters long, which causes some unaligned wrapping of comments on the website. This PR reduces all lines' length to a maximum of 80.
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Keating950 2020-02-07 10:01:00 -05:00 committed by GitHub
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commit 1274a06704
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1 changed files with 54 additions and 43 deletions
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@ -39,28 +39,30 @@ gateways and routers.
_float: .float 3.14 # 4 bytes _float: .float 3.14 # 4 bytes
_double: .double 7.0 # 8 bytes _double: .double 7.0 # 8 bytes
.align 2 # Memory alignment of data, where .align 2 # Memory alignment of data, where
# number indicates byte alignment in # number indicates byte alignment
# powers of 2. (.align 2 represents # in powers of 2. (.align 2
# word alignment since 2^2 = 4 bytes) # represents word alignment since
# 2^2 = 4 bytes)
.text # Section that contains instructions .text # Section that contains
# and program logic # instructions and program logic
.globl _main # Declares an instruction label as .globl _main # Declares an instruction label as
# global, making it accessible to # global, making it accessible to
# other files # other files
_main: # MIPS programs execute instructions _main: # MIPS programs execute
# sequentially, where the code under # instructions sequentially, where
# this label will be executed firsts # the code under this label will be
# executed first
# Let's print "hello world" # Let's print "hello world"
la $a0, hello_world # Load address of string stored in la $a0, hello_world # Load address of string stored
# memory # in memory
li $v0, 4 # Load the syscall value (indicating li $v0, 4 # Load the syscall value (number
# type of functionality) # indicating which syscall to make)
syscall # Perform the specified syscall with syscall # Perform the specified syscall
# the given argument ($a0) # with the given argument ($a0)
# Registers (used to hold data during program execution) # Registers (used to hold data during program execution)
# $t0 - $t9 # Temporary registers used for # $t0 - $t9 # Temporary registers used for
@ -79,22 +81,24 @@ gateways and routers.
# Types of load/store instructions # Types of load/store instructions
la $t0, label # Copy the address of a value in la $t0, label # Copy the address of a value in
# memory specified by the label into # memory specified by the label
# register $t0 # into register $t0
lw $t0, label # Copy a word value from memory lw $t0, label # Copy a word value from memory
lw $t1, 4($s0) # Copy a word value from an address lw $t1, 4($s0) # Copy a word value from an address
# stored in a register with an offset # stored in a register with an
# of 4 bytes (addr + 4) # offset of 4 bytes (addr + 4)
lb $t2, label # Copy a byte value to the lower order lb $t2, label # Copy a byte value to the
# portion of the register $t2 # lower order portion of
# the register $t2
lb $t2, 0($s0) # Copy a byte value from the source lb $t2, 0($s0) # Copy a byte value from the source
# address in $s0 with offset 0 # address in $s0 with offset 0
# Same idea with 'lh' for halfwords # Same idea with 'lh' for halfwords
sw $t0, label # Store word value into memory address sw $t0, label # Store word value into
# mapped by label # memory address mapped by label
sw $t0, 8($s0) # Store word value into address sw $t0, 8($s0) # Store word value into address
# specified in $s0 and offset of 8 bytes # specified in $s0 and offset of
# 8 bytes
# Same idea using 'sb' and 'sh' for bytes and halfwords. 'sa' does not exist # Same idea using 'sb' and 'sh' for bytes and halfwords. 'sa' does not exist
### Math ### ### Math ###
@ -108,20 +112,22 @@ gateways and routers.
mul $t2, $t0, $t1 # $t2 = $t0 * $t1 mul $t2, $t0, $t1 # $t2 = $t0 * $t1
div $t2, $t0, $t1 # $t2 = $t0 / $t1 (Might not be div $t2, $t0, $t1 # $t2 = $t0 / $t1 (Might not be
# supported in some versons of MARS) # supported in some versons of MARS)
div $t0, $t1 # Performs $t0 / $t1. Get the quotient div $t0, $t1 # Performs $t0 / $t1. Get the
# using 'mflo' and remainder using 'mfhi' # quotient using 'mflo' and
# remainder using 'mfhi'
# Bitwise Shifting # Bitwise Shifting
sll $t0, $t0, 2 # Bitwise shift to the left with sll $t0, $t0, 2 # Bitwise shift to the left with
# immediate (constant value) of 2 # immediate (constant value) of 2
sllv $t0, $t1, $t2 # Shift left by a variable amount in sllv $t0, $t1, $t2 # Shift left by a variable amount
# register # in register
srl $t0, $t0, 5 # Bitwise shift to the right (does srl $t0, $t0, 5 # Bitwise shift to the right (does
# not sign preserve, sign-extends with 0) # not sign preserve, sign-extends
srlv $t0, $t1, $t2 # Shift right by a variable amount in # with 0)
# a register srlv $t0, $t1, $t2 # Shift right by a variable amount
sra $t0, $t0, 7 # Bitwise arithmetic shift to the right # in a register
# (preserves sign) sra $t0, $t0, 7 # Bitwise arithmetic shift to
# the right (preserves sign)
srav $t0, $t1, $t2 # Shift right by a variable amount srav $t0, $t1, $t2 # Shift right by a variable amount
# in a register # in a register
@ -146,7 +152,8 @@ gateways and routers.
# $t0 == $t1, otherwise # $t0 == $t1, otherwise
# execute the next line # execute the next line
bne $t0, $t1, reg_neq # Branches when $t0 != $t1 bne $t0, $t1, reg_neq # Branches when $t0 != $t1
b branch_target # Unconditional branch, will always execute b branch_target # Unconditional branch, will
# always execute
beqz $t0, req_eq_zero # Branches when $t0 == 0 beqz $t0, req_eq_zero # Branches when $t0 == 0
bnez $t0, req_neq_zero # Branches when $t0 != 0 bnez $t0, req_neq_zero # Branches when $t0 != 0
bgt $t0, $t1, t0_gt_t1 # Branches when $t0 > $t1 bgt $t0, $t1, t0_gt_t1 # Branches when $t0 > $t1
@ -155,8 +162,9 @@ gateways and routers.
blt $t0, $t1, t0_gt_t1 # Branches when $t0 < $t1 blt $t0, $t1, t0_gt_t1 # Branches when $t0 < $t1
ble $t0, $t1, t0_gte_t1 # Branches when $t0 <= $t1 ble $t0, $t1, t0_gte_t1 # Branches when $t0 <= $t1
bltz $t0, t0_lt0 # Branches when $t0 < 0 bltz $t0, t0_lt0 # Branches when $t0 < 0
slt $s0, $t0, $t1 # Instruction that sends a signal when slt $s0, $t0, $t1 # Instruction that sends a signal
# $t0 < $t1 with result in $s0 (1 for true) # when $t0 < $t1 with result in $s0
# (1 for true)
# Simple if statement # Simple if statement
# if (i == j) # if (i == j)
@ -183,14 +191,14 @@ gateways and routers.
# max = c; # max = c;
# Let $s0 = a, $s1 = b, $s2 = c, $v0 = return register # Let $s0 = a, $s1 = b, $s2 = c, $v0 = return register
ble $s0, $s1, a_LTE_b # if (a <= b) branch(a_LTE_b) ble $s0, $s1, a_LTE_b # if(a <= b) branch(a_LTE_b)
ble $s0, $s2, max_C # if (a > b && a <=c) branch(max_C) ble $s0, $s2, max_C # if(a > b && a <=c) branch(max_C)
move $v0, $s1 # else [a > b && a > c] max = a move $v0, $s1 # else [a > b && a > c] max = a
j done # Jump to the end of the program j done # Jump to the end of the program
a_LTE_b: # Label for when a <= b a_LTE_b: # Label for when a <= b
ble $s1, $s2, max_C # if (a <= b && b <= c) branch(max_C) ble $s1, $s2, max_C # if(a <= b && b <= c) branch(max_C)
move $v0, $s1 # if (a <= b && b > c) max = b move $v0, $s1 # if(a <= b && b > c) max = b
j done # Jump to done j done # Jump to done
max_C: max_C:
@ -204,9 +212,11 @@ gateways and routers.
instruction to continue its execution instruction to continue its execution
li $t0, 0 li $t0, 0
while: while:
bgt $t0, 10, end_while # While $t0 is less than 10, keep iterating bgt $t0, 10, end_while # While $t0 is less than 10,
# keep iterating
addi $t0, $t0, 1 # Increment the value addi $t0, $t0, 1 # Increment the value
j while # Jump back to the beginning of the loop j while # Jump back to the beginning of
# the loop
end_while: end_while:
# 2D Matrix Traversal # 2D Matrix Traversal
@ -246,7 +256,8 @@ gateways and routers.
# How about recursion? # How about recursion?
# This is a bit more work since we need to make sure we save and restore # This is a bit more work since we need to make sure we save and restore
# the previous PC in $ra since jal will automatically overwrite on each call # the previous PC in $ra since jal will automatically overwrite
# on each call
li $a0, 3 li $a0, 3
jal fact jal fact