Consider function print()documented below in pseudocode in the function\'s heade

Question

Consider function print()documented below in pseudocode in the function's header comment block The input parameter, msg, contains the address in memory of the string to be displayed; this string is defined in the.data section. After displaying the string, by calling SysPrintStr(), it displays the integer parameter n by calling SysPrintlnt (). Note that print() is a leaf procedure since it does not call other functions. This means we do not need to save $ra in print()'s stack frame. Furthermore, since this function is small and simple enough, we can get by without allocating a stack frame at all; this is the way we shall write print(). For this exercise, write the MIPS32 assembly language code that implements print(). My optimized implementation required 6 instructions: two addi, one jr, one move, and two syscall. Note, you are not being asked to write a complete program; just implement print(). However, for testing purposes, you should write a driver main() function that calls print() to verify it works correctly.

Explanation / Answer

.Ltext0: .local _ZStL8__ioinit .comm _ZStL8__ioinit,1,1 .globl main main: .LFB971: .cfi_startproc 0000 55 pushq %rbp .cfi_def_cfa_offset 16 .cfi_offset 6, -16 0001 4889E5 movq %rsp, %rbp .cfi_def_cfa_register 6 0004 4883EC30 subq $48, %rsp 0008 64488B04 movq %fs:40, %rax 25280000 00 0011 488945F8 movq %rax, -8(%rbp) 0015 31C0 xorl %eax, %eax .LBB2: 0017 48B84865 movabsq $8031924123371070792, %rax 6C6C6F20 776F 0021 488945E0 movq %rax, -32(%rbp) 0025 C745E872 movl $560229490, -24(%rbp) 6C6421 002c C645EC00 movb $0, -20(%rbp) 0030 C745DC0A movl $10, -36(%rbp) 000000 0037 8B55DC movl -36(%rbp), %edx 003a 488D45E0 leaq -32(%rbp), %rax 003e 89D6 movl %edx, %esi 0040 4889C7 movq %rax, %rdi 0043 E8000000 call _Z7displayPci 00 0048 B8000000 movl $0, %eax 00 .LBE2: 004d 488B4DF8 movq -8(%rbp), %rcx 0051 6448330C xorq %fs:40, %rcx 25280000 00 005a 7405 je .L3 005c E8000000 call __stack_chk_fail 00 .L3: 0061 C9 leave .cfi_def_cfa 7, 8 0062 C3 ret .cfi_endproc .LFE971: .globl _Z7displayPci _Z7displayPci: .LFB972: .cfi_startproc 0063 55 pushq %rbp .cfi_def_cfa_offset 16 .cfi_offset 6, -16 0064 4889E5 movq %rsp, %rbp .cfi_def_cfa_register 6 0067 4883EC10 subq $16, %rsp 006b 48897DF8 movq %rdi, -8(%rbp) 006f 8975F4 movl %esi, -12(%rbp) 0072 488B45F8 movq -8(%rbp), %rax 0076 4889C7 movq %rax, %rdi 0079 E8000000 call _Z11sysPrintStrPc 00 007e 8B45F4 movl -12(%rbp), %eax 0081 89C7 movl %eax, %edi 0083 E8000000 call _Z11sysPrintInti 00 0088 C9 leave .cfi_def_cfa 7, 8 0089 C3 ret .cfi_endproc .LFE972: .section .rodata .LC0: 0000 54686520 .string "The message is" 6D657373 61676520 697300 .text .globl _Z11sysPrintStrPc _Z11sysPrintStrPc: .LFB973: .cfi_startproc 008a 55 pushq %rbp .cfi_def_cfa_offset 16 .cfi_offset 6, -16 008b 4889E5 movq %rsp, %rbp .cfi_def_cfa_register 6 008e 4883EC10 subq $16, %rsp 0092 48897DF8 movq %rdi, -8(%rbp) 0096 BE000000 movl $.LC0, %esi 00 009b BF000000 movl $_ZSt4cout, %edi 00 00a0 E8000000 call _ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc 00 00a5 488B55F8 movq -8(%rbp), %rdx 00a9 4889D6 movq %rdx, %rsi 00ac 4889C7 movq %rax, %rdi 00af E8000000 call _ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc 00 00b4 C9 leave .cfi_def_cfa 7, 8 00b5 C3 ret .cfi_endproc .LFE973: .section .rodata .LC1: 000f 74686520 .string "the number is" 6E756D62 65722069 7300 .text .globl _Z11sysPrintInti _Z11sysPrintInti: .LFB974: .cfi_startproc 00b6 55 pushq %rbp .cfi_def_cfa_offset 16 .cfi_offset 6, -16 00b7 4889E5 movq %rsp, %rbp .cfi_def_cfa_register 6 00ba 4883EC10 subq $16, %rsp 00be 897DFC movl %edi, -4(%rbp) 00c1 BE000000 movl $.LC1, %esi 00 00c6 BF000000 movl $_ZSt4cout, %edi 00 00cb E8000000 call _ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc 00 00d0 8B55FC movl -4(%rbp), %edx 00d3 89D6 movl %edx, %esi 00d5 4889C7 movq %rax, %rdi 00d8 E8000000 call _ZNSolsEi 00 00dd C9 leave .cfi_def_cfa 7, 8 00de C3 ret .cfi_endproc .LFE974: _Z41__static_initialization_and_destruction_0ii: .LFB978: 00fc BF000000 movl $_ZStL8__ioinit, %edi 00 0101 E8000000 call _ZNSt8ios_base4InitC1Ev 00 0106 BA000000 movl $__dso_handle, %edx 00 010b BE000000 movl $_ZStL8__ioinit, %esi 00 0110 BF000000 movl $_ZNSt8ios_base4InitD1Ev, %edi 00 0115 E8000000 call __cxa_atexit 00 .cfi_startproc 00df 55 pushq %rbp .cfi_def_cfa_offset 16 .cfi_offset 6, -16 00e0 4889E5 movq %rsp, %rbp .cfi_def_cfa_register 6 00e3 4883EC10 subq $16, %rsp 00e7 897DFC movl %edi, -4(%rbp) 00ea 8975F8 movl %esi, -8(%rbp) 00ed 837DFC01 cmpl $1, -4(%rbp) 00f1 7527 jne .L7 00f3 817DF8FF cmpl $65535, -8(%rbp) FF0000 00fa 751E jne .L7 .L7: 011a C9 leave .cfi_def_cfa 7, 8 011b C3 ret .cfi_endproc .LFE978: _GLOBAL__sub_I_main: .LFB979: .cfi_startproc 011c 55 pushq %rbp .cfi_def_cfa_offset 16 .cfi_offset 6, -16 011d 4889E5 movq %rsp, %rbp .cfi_def_cfa_register 6 0120 BEFFFF00 movl $65535, %esi 00 0125 BF010000 movl $1, %edi 00 012a E8B0FFFF call _Z41__static_initialization_and_destruction_0ii FF 012f 5D popq %rbp .cfi_def_cfa 7, 8 0130 C3 ret .cfi_endproc .LFE979: .section .init_array,"aw" .align 8 0000 00000000 .quad _GLOBAL__sub_I_main 00000000 .text .Letext0:

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