#======================================================================
# power.s
# Control Transfer Instructions
#======================================================================

#======================================================================
   .section ".rodata"
#======================================================================

pcPrompt1:
   .asciz "Enter the base:  "

pcPrompt2:
   .asciz "Enter the exponent:  "

pcScanfFormat:
   .asciz "%d"

pcResult:
   .asciz "%d raised to the %d power is %d.\n"

#======================================================================
   .section ".data"
#======================================================================

piPower:
   .long 1

#======================================================================
   .section ".bss"
#======================================================================

piBase:
   .skip 4

piExp:
   .skip 4

piIndex:
   .skip 4

#======================================================================
   .section ".text"
#======================================================================

#----------------------------------------------------------------------
# int main(int argc, char *argv[])
#
# Read a non-negative base and exponent from stdin.  Write base 
# raised to the exponent power to stdout.
#
# Formal parameter offsets:
   .equ ARGC, 8
   .equ ARGV, 12
#----------------------------------------------------------------------

   .globl main
   .type main,@function

main:

   pushl %ebp
   movl  %esp, %ebp

   # printf("Enter the base:  ");
   pushl $pcPrompt1
   call  printf
   addl  $4, %esp

   # scanf("%d", &iBase); 
   pushl $piBase 
   pushl $pcScanfFormat
   call  scanf
   addl  $8, %esp

   # printf("Enter the exponent:  ");
   pushl $pcPrompt2
   call  printf
   addl  $4, %esp

   # scanf("%d", &iExp); 
   pushl $piExp 
   pushl $pcScanfFormat
   call  scanf
   addl  $8, %esp

   # iIndex = 1;
   movl  $1, piIndex

loop1:

   # if (iIndex > iExp) goto loopend1;
   movl  piIndex, %eax
   cmpl  piExp, %eax
   jg    loopend1

   # iPower *= iBase;
   movl  piPower, %eax
   imull piBase
   movl  %eax, piPower
   
   # iIndex++;
   incl  piIndex

   # goto loop1;
   jmp   loop1

loopend1:

   # printf("%d to the %d power is %d.\n", iBase, iExp, iPower); 
   pushl piPower
   pushl piExp
   pushl piBase
   pushl $pcResult
   call  printf
   addl  $16, %esp

   # return 0;
   movl  $0, %eax
   movl  %ebp, %esp
   popl  %ebp
   ret