Mechanisms are provided for analyzing and optimizing loops with conditional control flow in source code based on array reference safety. Mechanisms are provided for analyzing blocks of the source code to identify a conditional control flow loop having loop source code specifying a total access range for an array reference. A safe access range, of the total access range of the array reference in the loop source code, is identified over which a compiler-based optimization of the loop source code can be safely applied without introducing new exception conditions. The compiler-based optimization of the loop source code is performed based on the identified safe access range to generate optimized code. The optimized code is output for generation of executable code for execution on a processor.