# test_02.s
#
# A testcase for Asm 4.
# ———– main() ———–
.text
.globl main
main:
# fill the sX registers (and fp) with junk. Each testcase will use a different
# set of values.
lui $fp, 0xdf42
ori $fp, $fp, 0x983b
lui $s0, 0x826e
ori $s0, $s0, 0x8575
lui $s1, 0x37f7
ori $s1, $s1, 0xf81d
lui $s2, 0x3c2a
ori $s2, $s2, 0x5954
lui $s3, 0x8da6
ori $s3, $s3, 0xceac
lui $s4, 0x00e7
ori $s4, $s4, 0x531d
lui $s5, 0xa14c
ori $s5, $s5, 0x17ee
lui $s6, 0x7e3f
ori $s6, $s6, 0x3457
lui $s7, 0x09c6
ori $s7, $s7, 0x7fb6
# instead of explicitly dumping the stack pointer, I’ll push a dummy
# variable onto the stack. Some students are reporting different
# stack values in their output.
lui $t0, 0xa302
ori $t0, $t0, 0xf09a
addiu $sp, $sp,-4
sw $t0, 0($sp)
.data
TEST_NAME_1:
.asciiz “Billy”
TEST_NAME_2:
.asciiz “Blinky”
TEST_NAME_3:
.asciiz “Pinky”
TEST_NAME_4:
.asciiz “Inky”
TEST_NAME_5:
.asciiz “Clyde”
TEST_NAME_6:
.asciiz “Bonnie”
TEST_NAME_7:
.asciiz “Prince”
TEST_NAME_8:
.asciiz “Charlie”
.word 0xabcdef01
TEST_TURTLE_ARRAY:
.byte 0
.byte 6
.byte 1
.byte 0
.word TEST_NAME_1
.word 387
.byte -10
.byte -3
.byte 2
.byte 0
.word TEST_NAME_2
.word 906
.byte 10
.byte 9
.byte 0
.byte 0
.word TEST_NAME_3
.word 763
.byte 10
.byte -9
.byte 2
.byte 0
.word TEST_NAME_4
.word 383
.byte -9
.byte 10
.byte 0
.byte 0
.word TEST_NAME_5
.word 559
.byte 0
.byte 5
.byte 3
.byte 0
.word TEST_NAME_6
.word 681
.byte -5
.byte 3
.byte 3
.byte 0
.word TEST_NAME_7
.word 144
.byte 1
.byte 2
.byte 3
.byte 0
.word TEST_NAME_8
.word 123
.word 0x23456789
TEST_TURTLE_ARRAY_LEN:
.word 8
.text
.data
NEEDLE_1:
.asciiz “No match”
NEEDLE_2:
.asciiz “Billy”
NEEDLE_3:
.asciiz “Charlie”
NEEDLE_4:
.asciiz “Bonnie_x”
NEEDLE_5:
.asciiz “Bonnie”
.text
la $a0, TEST_TURTLE_ARRAY
la $a1, TEST_TURTLE_ARRAY_LEN
lw $a1, 0($a1)
la $a2, NEEDLE_1
jal turtle_searchName
add $a0, $v0,$zero # print_int(retval)
addi $v0, $zero,1
syscall
addi $v0, $zero,11 # print_char(‘\n’)
addi $a0, $zero,’\n’
syscall
la $a0, TEST_TURTLE_ARRAY
la $a1, TEST_TURTLE_ARRAY_LEN
lw $a1, 0($a1)
la $a2, NEEDLE_2
jal turtle_searchName
add $a0, $v0,$zero # print_int(retval)
addi $v0, $zero,1
syscall
addi $v0, $zero,11 # print_char(‘\n’)
addi $a0, $zero,’\n’
syscall
la $a0, TEST_TURTLE_ARRAY
la $a1, TEST_TURTLE_ARRAY_LEN
lw $a1, 0($a1)
la $a2, NEEDLE_3
jal turtle_searchName
add $a0, $v0,$zero # print_int(retval)
addi $v0, $zero,1
syscall
addi $v0, $zero,11 # print_char(‘\n’)
addi $a0, $zero,’\n’
syscall
la $a0, TEST_TURTLE_ARRAY
la $a1, TEST_TURTLE_ARRAY_LEN
lw $a1, 0($a1)
la $a2, NEEDLE_4
jal turtle_searchName
add $a0, $v0,$zero # print_int(retval)
addi $v0, $zero,1
syscall
addi $v0, $zero,11 # print_char(‘\n’)
addi $a0, $zero,’\n’
syscall
la $a0, TEST_TURTLE_ARRAY
la $a1, TEST_TURTLE_ARRAY_LEN
lw $a1, 0($a1)
la $a2, NEEDLE_5
jal turtle_searchName
add $a0, $v0,$zero # print_int(retval)
addi $v0, $zero,1
syscall
addi $v0, $zero,11 # print_char(‘\n’)
addi $a0, $zero,’\n’
syscall
# dump out all of the registers.
.data
TESTCASE_DUMP1: .ascii “\n”
.ascii “+———————————————————–+\n”
.ascii “| Magic Value (popped from the stack): |\n”
.asciiz “+———————————————————–+\n”
TESTCASE_DUMP2: .ascii “\n”
.ascii “+———————————————————–+\n”
.ascii “| Testcase Register Dump (fp, then 8 sX regs): |\n”
.asciiz “+———————————————————–+\n”
.text
addi $v0, $zero, 4 # print_str(TESTCASE_DUMP1)
la $a0, TESTCASE_DUMP1
syscall
# we pop this from the stack so that, if the stack pointer is not
# predictable, we’ll still get reliable results.
lw $a0, 0($sp)
addiu $sp, $sp,4
jal printHex
# the rest of the registers have hard-coded values
addi $v0, $zero, 4 # print_str(TESTCASE_DUMP2)
la $a0, TESTCASE_DUMP2
syscall
add $a0, $fp, $zero
jal printHex
add $a0, $s0, $zero
jal printHex
add $a0, $s1, $zero
jal printHex
add $a0, $s2, $zero
jal printHex
add $a0, $s3, $zero
jal printHex
add $a0, $s4, $zero
jal printHex
add $a0, $s5, $zero
jal printHex
add $a0, $s6, $zero
jal printHex
add $a0, $s7, $zero
jal printHex
# terminate the program
addi $v0, $zero, 10 # syscall_exit
syscall
# never get here!
# —- some functions that the student code can call —-
# int strcmp(char *a, char *b)
# {
# char *p1 = a;
# char *p2 = b;
#
# while (*p1 != ‘\0’ && *p2 != ‘\0’ && *p1 == *p2)
# {
# p1++;
# p2++;
# }
#
# return *p1 – *p2;
# }
#
# REGISTERS
# t0 – p1
# t1 – p2
# t2 – *p1
# t3 – *p2
# t8 – various temporaries
.globl strcmp
strcmp:
# standard prologue
addiu $sp, $sp, -24
sw $fp, 0($sp)
sw $ra, 4($sp)
addiu $fp, $sp, 20
add $t0, $a0,$zero # p1 = a
add $t1, $a1,$zero # p2 = b
strcmp_LOOP:
lb $t2, 0($t0) # read *p1
lb $t3, 0($t1) # read *p2
beq $t2,$zero, strcmp_DONE # if (*p1 == ‘\0’) break
beq $t3,$zero, strcmp_DONE # if (*p2 == ‘\0’) break
bne $t2,$t3, strcmp_DONE # if (*p1 != *p2 ) break
addi $t0, $t0,1 # p1++
addi $t1, $t1,1 # p2++
j strcmp_LOOP
strcmp_DONE:
sub $v0, $t2,$t3 # return *p1 – *p2
# standard epilogue
lw $ra, 4($sp)
lw $fp, 0($sp)
addiu $sp, $sp, 24
jr $ra
# —- UTILITY FUNCTIONS, FOR THE TESTCASE ITSELF —-
debug_turtle_move:
# standard prologue
addiu $sp, $sp, -24
sw $fp, 0($sp)
sw $ra, 4($sp)
addiu $fp, $sp, 20
addiu $sp, $sp,-8
sw $a0, 0($sp)
sw $a1, 4($sp)
.data
debug_turtle_move_MSG:
.asciiz “turtle_move ”
.text
addi $v0, $zero,4
la $a0, debug_turtle_move_MSG
syscall
addi $v0, $zero,1 # print_int(dist)
lw $a0, 4($sp)
syscall
addi $v0, $zero,11 # print_char(‘\n’)
addi $a0, $zero,’\n’
syscall
# turtle_move(obj,dist)
lw $a0, 0($sp)
lw $a1, 4($sp)
addiu $sp, $sp,8
jal turtle_move
# standard epilogue
lw $ra, 4($sp)
lw $fp, 0($sp)
addiu $sp, $sp, 24
jr $ra
debug_turtle_turnLeft:
# standard prologue
addiu $sp, $sp, -24
sw $fp, 0($sp)
sw $ra, 4($sp)
addiu $fp, $sp, 20
addiu $sp, $sp,-4
sw $a0, 0($sp)
.data
debug_turtle_turnLeft_MSG:
.asciiz “turtle_turnLeft\n”
.text
addi $v0, $zero,4
la $a0, debug_turtle_turnLeft_MSG
syscall
# turtle_turnLeft(obj)
lw $a0, 0($sp)
addiu $sp, $sp,4
jal turtle_turnLeft
# standard epilogue
lw $ra, 4($sp)
lw $fp, 0($sp)
addiu $sp, $sp, 24
jr $ra
debug_turtle_turnRight:
# standard prologue
addiu $sp, $sp, -24
sw $fp, 0($sp)
sw $ra, 4($sp)
addiu $fp, $sp, 20
addiu $sp, $sp,-4
sw $a0, 0($sp)
.data
debug_turtle_turnRight_MSG:
.asciiz “turtle_turnRight\n”
.text
addi $v0, $zero,4
la $a0, debug_turtle_turnRight_MSG
syscall
# turtle_turnLeft(obj)
lw $a0, 0($sp)
addiu $sp, $sp,4
jal turtle_turnRight
# standard epilogue
lw $ra, 4($sp)
lw $fp, 0($sp)
addiu $sp, $sp, 24
jr $ra
testcase_dump_bytes:
# standard prologue
addiu $sp, $sp, -24
sw $fp, 0($sp)
sw $ra, 4($sp)
addiu $fp, $sp, 20
# save the sX registers
addiu $sp $sp,-4
sw $s0, 0($sp)
# s0 will save the address of the Turtle object
add $s0, $a0,$zero
# print out the 4 bytes before the struct (to check for underruns)
lw $a0, -4($s0)
jal printHex
# print out the 12 bytes of the struct. But we’ll not print the
# ‘name’ field directly (since the address of the string is
# unpredictable); instead, we’ll print out the first 4 bytes of
# the pointed-to string
lb $a0, 0($s0)
addi $a1, $zero,2
jal printHex_size
lb $a0, 1($s0)
addi $a1, $zero,2
jal printHex_size
lb $a0, 2($s0)
addi $a1, $zero,2
jal printHex_size
lb $a0, 3($s0)
addi $a1, $zero,2
jal printHex_size
lw $a0, 4($s0)
lb $a0, 0($a0)
addi $a1, $zero,2
jal printHex_size
lw $a0, 4($s0)
lb $a0, 1($a0)
addi $a1, $zero,2
jal printHex_size
lw $a0, 4($s0)
lb $a0, 2($a0)
addi $a1, $zero,2
jal printHex_size
lw $a0, 4($s0)
lb $a0, 3($a0)
addi $a1, $zero,2
jal printHex_size
lb $a0, 8($s0)
addi $a1, $zero,2
jal printHex_size
lb $a0, 9($s0)
addi $a1, $zero,2
jal printHex_size
lb $a0, 10($s0)
addi $a1, $zero,2
jal printHex_size
lb $a0, 11($s0)
addi $a1, $zero,2
jal printHex_size
# print out the 4 bytes after the struct (to check for overruns)
lw $a0, 12($s0)
jal printHex
# print_char(‘\n’)
addi $v0, $zero,11
addi $a0, $zero,’\n’
syscall
# restore the sX registers
lw $s0, 0($sp)
addiu $sp $sp,4
# standard epilogue
lw $ra, 4($sp)
lw $fp, 0($sp)
addiu $sp, $sp, 24
jr $ra
# void printHex(int val)
# {
# printHex_recurse(val, 8);
# printf(“\n”);
# }
printHex:
# standard prologue
addiu $sp, $sp, -24
sw $fp, 0($sp)
sw $ra, 4($sp)
addiu $fp, $sp, 20
# printHex(val, 8)
addi $a1, $zero, 8
jal printHex_recurse
addi $v0, $zero, 11 # print_char(‘\n’)
addi $a0, $zero, 0xa
syscall
# standard epilogue
lw $ra, 4($sp)
lw $fp, 0($sp)
addiu $sp, $sp, 24
jr $ra
# void printHex_size(int val, int digits)
# {
# printHex_recurse(val, digits);
# printf(“\n”);
# }
printHex_size:
# standard prologue
addiu $sp, $sp, -24
sw $fp, 0($sp)
sw $ra, 4($sp)
addiu $fp, $sp, 20
# printHex_recurse(val, digits)
jal printHex_recurse
addi $v0, $zero, 11 # print_char(‘\n’)
addi $a0, $zero, 0xa
syscall
# standard epilogue
lw $ra, 4($sp)
lw $fp, 0($sp)
addiu $sp, $sp, 24
jr $ra
printHex_recurse:
# standard prologue
addiu $sp, $sp, -24
sw $fp, 0($sp)
sw $ra, 4($sp)
addiu $fp, $sp, 20
# if (len == 0) return; // base case (NOP)
beq $a1, $zero, printHex_recurse_DONE
# recurse first, before we print this character.
#
# The reason for this is because the easiest way to break up
# a long integer is using a small shift and modulo; so *this*
# call will be responsible for the *last* hex digit, and we’ll
# use recursion to handle the things which come *before* it.
#
# As we’ve seen just above, if the current len==1, then the
# recursive call will be the base case, and a NOP.
# of course, we have to save a0 before we recurse. We do *NOT*
# need to save a1, since we’ll never need it again.
sw $a0, 8($sp)
# printHex_recurse(val >> 4, len-1)
srl $a0, $a0,4
addi $a1, $a1,-1
jal printHex_recurse
# restore a0
lw $a0, 8($sp)
# the value we will print is (val & 0xf), interpreted as hex.
andi $t0, $a0,0x0f # digit = (val & 0xf)
slti $t1, $t0,10 # t1 = (digit < 10) beq $t1, $zero, printHex_recurse_LETTER # if we get here, then $t0 contains an integer from 0 to 9, inclusive. addi $v0, $zero, 11 # print_char(digit+'0') addi $a0, $t0, '0' syscall j printHex_recurse_DONE printHex_recurse_LETTER: # if we get here, then $t0 contains an integer from 10 to 15, inclusive. # convert to the equivalent letter. addi $t0, $t0,-10 # digit -= 10 addi $v0, $zero, 11 # print_char(digit+'a') addi $a0, $t0, 'a' syscall # intentional fall-through to the epilogue printHex_recurse_DONE: # standard epilogue lw $ra, 4($sp) lw $fp, 0($sp) addiu $sp, $sp, 24 jr $ra