[Python] MIPS li $at, float comment inserter

'''
    Author: fastman92

    Description:
        in MIPS executable you may often see instructions like this:
            li      $at, 0x40555555

            0x40555555 is really a float 32-bit value.

            However since IDA Pro sees a non-float register ($at) it will not show a float, but an integer.

            This script will put a comment like this:
                # float: 3.33333
'''

import struct

APPLICATION_NAME = "MIPS li $at, float comment inserter"

def f2b(f):
    return struct.unpack('I',struct.pack('f',f))[0]

def b2f(b):
    return struct.unpack('f',struct.pack('I',b))[0]

def isWhole(x):
    if(x%1 == 0):
        return True
    else:
        return False

def floatToStr(num):
    if(isWhole(num)):
        return "%g.0" % (num)
    else:
        return "%g" % (num)

def main():
    Message("---- Start of MIPS li $at, float comment inserter 1.1 by fastman92 ----\n")

    seg = FirstSeg()

    while seg != BADADDR:
        loc = SegStart(seg)

        while loc != BADADDR and loc < SegEnd(seg):
            if GetMnem(loc) == 'li':
                firstOp = GetOpnd(loc, 0)
                secondType = GetOpType(loc, 1)

                if firstOp == "$at" and secondType == o_imm:
                    comment = GetCommentEx(loc, False)

                    if comment == None or comment.startswith( 'float:'):
                        value = GetOperandValue(loc, 1)
                        value = b2f(value)

                        MakeComm(loc, "float: " + floatToStr(value))

                        print "0x%X - comment with float value %g inserted" % (loc, value)

            loc = NextHead(loc, BADADDR)

        seg = NextSeg(seg)

    Message("---- End of MIPS li $at, float comment inserter 1.1 by fastman92 ----\n")

main()