feat(array_maker): new file for creating the array structure

1 files changed, 154 insertions, 0 deletions

diff --git a/src/array_maker.s b/src/array_maker.s
new file mode 100644
index 0000000..d4c0afc
--- /dev/null
+++ b/src/array_maker.s
@@ -0,0 +1,154 @@
+# --------------------------------------------
+# FUNCTION: make_array_from_file
+# PURPOSE : Take a file descriptor, and convert it to the array data structure
+# INPUTS  : rdi = File descriptor
+# OUTPUTS : rax = Pointer to start of array in memory 
+#           rdx = Length of array in 8 byte chunks (the number of elements)
+# CLOBBERS: rax, rsi
+# --------------------------------------------
+.globl make_array_from_file
+.type make_array_from_file, @function
+ make_array_from_file:
+
+    push %r15
+    push %r14
+    push %r13
+    push %r12
+
+    # The file descriptor is in rdi
+    call create_file_buffer
+    movq %rax, %rdi         # Select pointer to file data
+    movq %rdx, %rsi         # Select length of file data
+
+    call make_pairwise_data # Make the pairwise data
+    movq %rax, %r15         # Save pointer to pariwise data in r15
+    movq %rdx, %r14         # Save the number of pairs in r14
+    
+    # Allocate space for the array
+    movq %r14, %rdi         # Select the number of coordinates 
+    imulq $8, %rdi          # 8 byte elements in array. Space for pointers
+    call allocate           
+    movq %rax, %r13         # Save array pointer in r13
+
+    # Add pointers in array that point to pairwise array. Pointer 0
+    # points to pair 0 and so on.
+    movq $0, %r12           # Counter for displacing pointers in array
+loop:
+    cmp %r14, %r12          # Compare number of pairs with the counter
+    je end
+
+    movq %r15, (%r13, %r12, 8) # Save pointer to pair_i in position_i in array
+    
+    addq $1, %r12           # Go to next spot in array
+    addq $16, %r15          # Go to next pair
+
+    jmp loop
+end:
+    movq %r13, %rax         # Return pointer to array
+    movq %r14, %rdx         # Return the number of elements in the array
+    
+    pop %r12
+    pop %r13
+    pop %r14
+    pop %r15
+
+    ret
+
+# --------------------------------------------
+# FUNCTION: make_pairwise_data
+# PURPOSE : Take the raw data from the file, and convert it to an array of x,y
+#           coordinates side by side: [x_1,y_1,x_2,y_2,...]
+# INPUTS  : rdi = Pointer to start of file data in memory
+#           rsi = Size of file
+# OUTPUTS : rax = Pointer to start of pairwise data in memory 
+#           rdx = The number of pairs 
+# CLOBBERS: rdi, rsi, rdx, rax
+# --------------------------------------------
+.globl make_pairwise_data
+.type make_pairwise_data, @function
+ make_pairwise_data:
+    push %r15
+    push %r14
+    push %r13
+    push %r12
+
+    movq %rdi, %r15     # Save file pointer in r15
+    movq %rsi, %r14     # Save file size in r14
+
+    # Count number of lines
+    movq %r15, %rdi     # Select the file pointer
+    movq %r14, %rsi     # Select the file size
+    call getLineCount
+    movq %rax, %r13     # Save number of lines (coordinates) in r13
+
+    # Allocate space for the pairwise coordinates after parseData
+    # The space allocated should be 2*(#coordinates)*8 bytes
+    imulq $16, %r13     # Multiply number of coordinates with 2*8
+    movq %r13, %rdi     # Select the number of coordinates
+    call allocate
+    movq %rax, %r12     # Save pointer to where pairwise data will be placed
+
+    # Parse the data from the file into the pairwise data, and place it into the
+    # allocated space
+    movq %r15, %rdi     # Select the pointer to the file data
+    movq %r14, %rsi     # Select size of file
+    movq %r12, %rdx     # Select memory location for where to put data
+    call parseData
+
+    # Divide r13 with 16, this is to go from total length of array to the number 
+    # of coordinates
+    movq %r13, %rax     # Use r13 as dividend
+    movq $16, %rdi      # Use 16 as divisor
+    cqo                 # Sign extend rax into rdx
+    idivq %rdi          # r13/16 -> quotient in rax
+
+    movq %rax, %rdx     # Return number of pairs (the quotient of division)
+    movq %r12, %rax     # Return pointer to pairwise data
+
+    pop %r12
+    pop %r13
+    pop %r14
+    pop %r15
+
+    ret
+
+# --------------------------------------------
+# FUNCTION: create_file_buffer
+# PURPOSE : Take a file descriptor and create a memory location and put the
+#           data of the file in that location.
+# INPUTS  : rdi = File descriptor
+# OUTPUTS : rax = Pointer to start of file in memory 
+#           rdx = Length of file in bytes
+# CLOBBERS: rax, rsi, rdi, rdx
+# --------------------------------------------
+.globl create_file_buffer
+.type create_file_buffer, @function
+ create_file_buffer:
+    
+    push %r15
+    push %r14
+    push %r13
+
+    movq %rdi, %r15     # Save file descriptor in r15
+    movq %r15, %rdi     # Select file descriptor
+    call getFileSize    # Get the file size
+    movq %rax, %r14     # Save file size in r14
+
+    movq %r14, %rdi     # Select file size
+    call allocate       # Allocate memory for file contents
+    movq %rax, %r13     # Save file buffer in r13
+
+    movq %r15, %rdi     # Select the file discriptor
+    movq %r13, %rsi     # Select the buffer to store input
+    movq %r14, %rdx     # Size to read from file
+    movq $0, %rax       # Select read syscall
+    syscall             # Read from the file
+
+    movq %r13, %rax     # Return pointer to start of file
+    movq %r14, %rdx     # Return length of file
+
+    pop %r13
+    pop %r14
+    pop %r15
+
+    ret