diff --git a/mips.html.markdown b/mips.html.markdown
index 45e16e7b..7f759bec 100644
--- a/mips.html.markdown
+++ b/mips.html.markdown
@@ -39,28 +39,30 @@ gateways and routers.
_float: .float 3.14 # 4 bytes
_double: .double 7.0 # 8 bytes
- .align 2 # Memory alignment of data, where
- # number indicates byte alignment in
- # powers of 2. (.align 2 represents
- # word alignment since 2^2 = 4 bytes)
+ .align 2 # Memory alignment of data, where
+ # number indicates byte alignment
+ # in powers of 2. (.align 2
+ # represents word alignment since
+ # 2^2 = 4 bytes)
-.text # Section that contains instructions
- # and program logic
+.text # Section that contains
+ # instructions and program logic
.globl _main # Declares an instruction label as
# global, making it accessible to
# other files
- _main: # MIPS programs execute instructions
- # sequentially, where the code under
- # this label will be executed firsts
+ _main: # MIPS programs execute
+ # instructions sequentially, where
+ # the code under this label will be
+ # executed first
# Let's print "hello world"
- la $a0, hello_world # Load address of string stored in
- # memory
- li $v0, 4 # Load the syscall value (indicating
- # type of functionality)
- syscall # Perform the specified syscall with
- # the given argument ($a0)
+ la $a0, hello_world # Load address of string stored
+ # in memory
+ li $v0, 4 # Load the syscall value (number
+ # indicating which syscall to make)
+ syscall # Perform the specified syscall
+ # with the given argument ($a0)
# Registers (used to hold data during program execution)
# $t0 - $t9 # Temporary registers used for
@@ -79,22 +81,24 @@ gateways and routers.
# Types of load/store instructions
la $t0, label # Copy the address of a value in
- # memory specified by the label into
- # register $t0
+ # memory specified by the label
+ # into register $t0
lw $t0, label # Copy a word value from memory
lw $t1, 4($s0) # Copy a word value from an address
- # stored in a register with an offset
- # of 4 bytes (addr + 4)
- lb $t2, label # Copy a byte value to the lower order
- # portion of the register $t2
+ # stored in a register with an
+ # offset of 4 bytes (addr + 4)
+ lb $t2, label # Copy a byte value to the
+ # lower order portion of
+ # the register $t2
lb $t2, 0($s0) # Copy a byte value from the source
# address in $s0 with offset 0
# Same idea with 'lh' for halfwords
- sw $t0, label # Store word value into memory address
- # mapped by label
+ sw $t0, label # Store word value into
+ # memory address mapped by label
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
### Math ###
@@ -108,20 +112,22 @@ gateways and routers.
mul $t2, $t0, $t1 # $t2 = $t0 * $t1
div $t2, $t0, $t1 # $t2 = $t0 / $t1 (Might not be
# supported in some versons of MARS)
- div $t0, $t1 # Performs $t0 / $t1. Get the quotient
- # using 'mflo' and remainder using 'mfhi'
+ div $t0, $t1 # Performs $t0 / $t1. Get the
+ # quotient using 'mflo' and
+ # remainder using 'mfhi'
# Bitwise Shifting
sll $t0, $t0, 2 # Bitwise shift to the left with
# immediate (constant value) of 2
- sllv $t0, $t1, $t2 # Shift left by a variable amount in
- # register
+ sllv $t0, $t1, $t2 # Shift left by a variable amount
+ # in register
srl $t0, $t0, 5 # Bitwise shift to the right (does
- # not sign preserve, sign-extends with 0)
- srlv $t0, $t1, $t2 # Shift right by a variable amount in
- # a register
- sra $t0, $t0, 7 # Bitwise arithmetic shift to the right
- # (preserves sign)
+ # not sign preserve, sign-extends
+ # with 0)
+ srlv $t0, $t1, $t2 # Shift right by a variable amount
+ # in a register
+ sra $t0, $t0, 7 # Bitwise arithmetic shift to
+ # the right (preserves sign)
srav $t0, $t1, $t2 # Shift right by a variable amount
# in a register
@@ -146,7 +152,8 @@ gateways and routers.
# $t0 == $t1, otherwise
# execute the next line
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
bnez $t0, req_neq_zero # Branches when $t0 != 0
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
ble $t0, $t1, t0_gte_t1 # Branches when $t0 <= $t1
bltz $t0, t0_lt0 # Branches when $t0 < 0
- slt $s0, $t0, $t1 # Instruction that sends a signal when
- # $t0 < $t1 with result in $s0 (1 for true)
+ slt $s0, $t0, $t1 # Instruction that sends a signal
+ # when $t0 < $t1 with result in $s0
+ # (1 for true)
# Simple if statement
# if (i == j)
@@ -183,14 +191,14 @@ gateways and routers.
# max = c;
# 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, $s2, max_C # if (a > b && a <=c) branch(max_C)
+ 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)
move $v0, $s1 # else [a > b && a > c] max = a
j done # Jump to the end of the program
a_LTE_b: # Label for when a <= b
- ble $s1, $s2, max_C # if (a <= b && b <= c) branch(max_C)
- move $v0, $s1 # if (a <= b && b > c) max = b
+ ble $s1, $s2, max_C # if(a <= b && b <= c) branch(max_C)
+ move $v0, $s1 # if(a <= b && b > c) max = b
j done # Jump to done
max_C:
@@ -204,9 +212,11 @@ gateways and routers.
instruction to continue its execution
li $t0, 0
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
- j while # Jump back to the beginning of the loop
+ j while # Jump back to the beginning of
+ # the loop
end_while:
# 2D Matrix Traversal
@@ -246,7 +256,8 @@ gateways and routers.
# How about recursion?
# 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
jal fact