CHAPTER 6.PRINTF()WITH SEVERAL ARGUMENTS CHAPTER 6.PRINTF()WITH SEVERAL ARGUMENTS
.text:00000050 li $a1, 1
; pass 3rd argument in $a2:
.text:00000054 li $a2, 2
; pass 4th argument in $a3:
.text:00000058 li $a3, 3
; call printf():
.text:0000005C lw $v0, (printf & 0xFFFF)($gp)
.text:00000060 or $at, $zero
.text:00000064 move $t9, $v0
.text:00000068 jalr $t9
.text:0000006C or $at, $zero ; NOP
; function epilogue:
.text:00000070 lw $gp, 0x38+var_10($fp)
; set return value to 0:
.text:00000074 move $v0, $zero
.text:00000078 move $sp, $fp
.text:0000007C lw $ra, 0x38+var_4($sp)
.text:00000080 lw $fp, 0x38+var_8($sp)
.text:00000084 addiu $sp, 0x38
; return
.text:00000088 jr $ra
.text:0000008C or $at, $zero ; NOP
6.4 Conclusion.
Here is a rough skeleton of the function call:
Listing 6.20: x86...
PUSH 3rd argument
PUSH 2nd argument
PUSH 1st argument
CALL function
; modify stack pointer (if needed)
Listing 6.21: x64 (MSVC)MOV RCX, 1st argument
MOV RDX, 2nd argument
MOV R8, 3rd argument
MOV R9, 4th argument
...
PUSH 5th, 6th argument, etc (if needed)
CALL function
; modify stack pointer (if needed)
Listing 6.22: x64 (GCC)MOV RDI, 1st argument
MOV RSI, 2nd argument
MOV RDX, 3rd argument
MOV RCX, 4th argument
MOV R8, 5th argument
MOV R9, 6th argument
...
PUSH 7th, 8th argument, etc (if needed)
CALL function
; modify stack pointer (if needed)
Listing 6.23: ARMMOV R0, 1st argument
MOV R1, 2nd argument
MOV R2, 3rd argument
MOV R3, 4th argument
; pass 5th, 6th argument, etc, in stack (if needed)
BL function
; modify stack pointer (if needed)