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POCompiling a C++ to smallest possible size
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copied!<p>I am curious about how I should go about compiling a relatively simple C++ script to its smallest possible executable size. </p> <p>Without going too much into <em>why</em> this program will be useful, here is my code:</p> <pre><code>#include <cstdlib> #include <stdio.h> #include <string> using namespace std; unsigned long long inputAdjust(const string myinput) { unsigned long long myadjust; if (myinput=="B") { myadjust=1; } else if (myinput=="K") { myadjust=1024; } else if (myinput=="M") { myadjust=1048576; } else if (myinput=="G") { myadjust=1073741824; } else { myadjust=1; } return myadjust; } long long asmAnswer (const string myinput, const unsigned long long fir, const unsigned long long sec) { unsigned long long myanswer; if (myinput=="A") { myanswer = fir + sec; } else if (myinput=="S") { myanswer = fir - sec; } else if (myinput=="M") { myanswer = fir * sec; } else { myanswer = fir + sec; } return myanswer; } double dAnswer (const unsigned long long fir, const unsigned long long sec) { double myanswer; myanswer = (double)fir/sec; return myanswer; } void outputAnswer (const string myinput, const long long myanswer) { if (myinput=="B") { printf("%lld",myanswer); } else if (myinput=="K") { printf("%.2f",(double)(myanswer/1024)); } else if (myinput=="M") { printf("%.2f",(double)(myanswer/1048576)); } else if (myinput=="G") { printf("%.2f",(double)(myanswer/1073741824)); } else if (myinput=="O") { if (myanswer>0) { if (myanswer<1024 && myanswer>-1024) { printf("%lld b",myanswer); } else if (myanswer<1048576 && myanswer>-1048576) { printf("%.2f kb",(double)(myanswer/1024)); } else if (myanswer<1073741824 && myanswer>-1073741824) { printf("%.2f mb",(double)(myanswer/1048576)); } else { printf("%.2f gb",(double)(myanswer/1073741824)); } } } else { //assume bytes printf("%lld",myanswer); } } void outputAnswer (const string myinput, const double myanswer) { if (myinput=="P") { printf("%.3f",(myanswer*100.0)); } else { printf("%.3f",myanswer); } } int main(int argc, char* argv[]) { if (argc < 5) { // If we have less than 5 arguments, output the usage string filename = argv[0]; printf("\nUsage: bytemath.exe BKMG BKMGO[P] ASMD FirstNum SecondNum\n First <OPERATOR> Second\n"); return 0; } else { string input = argv[1]; string output = argv[2]; string oper = argv[3]; unsigned long long first = atoll(argv[4]); unsigned long long second = atoll(argv[5]); unsigned long i_adjust; unsigned long o_adjust; i_adjust = inputAdjust(input); first *= i_adjust; second*= i_adjust; if (oper=="D") { // we want to divide so need to use a double rather than long double answer; answer = dAnswer(first, second); outputAnswer(output, answer); } else { // otherwise do +, -, or * long long answer; answer = asmAnswer(oper, first, second); outputAnswer(output, answer); } return 1; } } </code></pre> <p>Basically it does math operations on large numbers because batch files can only work with 32-bit unsigned integers. I could probably just use something like VBS but this is the solution I'm working with at the moment. </p> <p>I need the program to be standalone, so it has to statically link to libraries. I was able to get the size down from ~570kb to ~148kb by replacing all the <code>cout</code> commands with <code>printf</code>, but I'm wondering what else I can do to get the file size down. </p> <p>I am compiling this with MiniGW 4.6, and this is my compile command at the moment: </p> <p><code>g++ -Os -s -static bytemath.cpp -o bytemath.exe</code></p> <p>Anything else I can do to reduce the file size without too much code rewriting? </p> <p>Thanks.</p> <p><em>EDIT</em></p> <p>The two big savers were getting rid of <code><iostream></code> and <code><string></code>, which I was able to do by replacing all my <code>cout</code> commands with <code>printf</code> and replacing my string comparisons with a char* comparison. For the chars, I needed to make sure to access the 0th element of the array and compare it to a char in single quotes rather than double quotes (i.e. <code>if (myinput[0]=='P') {</code> rather than <code>if (myinput=="P") {</code>).</p> <p>Thanks again everyone! 570kb to 18kb, works for me!</p>

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