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copied!<p>Measuring things, part 2. I have now got two programs. The first is in C and is compiled with gcc -O2:</p> <pre><code>#include <stdio.h> #include <time.h> #define BIG 1000000 int f( int n ) { int r = 0, i = 0; for ( i = 0; i < 1000; i++ ) { r += i; if ( n == BIG - 1 ) { return -1; } } return r; } int main() { clock_t start = clock(); int i = 0, z = 0; for ( i = 0; i < BIG; i++ ) { if ( (z = f(i)) == -1 ) { break; } } double t = (double)(clock() - start) / CLOCKS_PER_SEC; printf( "%f\n", t ); printf( "%d\n", z ); } </code></pre> <p>The second is C++, with exception handling, compiled with g++ -O2:</p> <pre><code>#include <stdio.h> #include <time.h> #define BIG 1000000 int f( int n ) { int r = 0, i = 0; for ( i = 0; i < 1000; i++ ) { r += i; if ( n == BIG - 1 ) { throw -1; } } return r; } int main() { clock_t start = clock(); int i = 0, z = 0; for ( i = 0; i < BIG; i++ ) { try { z += f(i); } catch( ... ) { break; } } double t = (double)(clock() - start) / CLOCKS_PER_SEC; printf( "%f\n", t ); printf( "%d\n", z ); } </code></pre> <p>I think these answer all the criticisms made of my last post.</p> <p><strong>Result: Execution times give the C version a 0.5% edge over the C++ version with exceptions, not the 10% that others have talked about (but not demonstrated)</strong></p> <p><strong><em>I'd be very grateful if others could try compiling and running the code (should only take a few minutes) in order to check that I have not made a horrible and obvious mistake anywhere. This is knownas "the scientific method"!</em></strong></p>

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