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Polly currently uses `getDebugLoc` in a few places to produce diagnostic output; this is correct when interacting with specific instructions, but may be incorrect when dealing with instruction ranges if debug intrinsics are included. As a general rule, the debug locations attached to debug intrinsics may be misleading compared to the surrounding instructions, and are not generally used for anything other than determining variable scope info; the recommended approach is therefore to use `getStableDebugLoc` instead, which skips over debug intrinsics. This is necessary to fix test failures that occur when enabling non-instruction debug info, which removes debug intrinsics from basic blocks and thus alters the diagnostic output of Polly (despite causing no functional change).
Polly - Polyhedral optimizations for LLVM ----------------------------------------- http://polly.llvm.org/ Polly uses a mathematical representation, the polyhedral model, to represent and transform loops and other control flow structures. Using an abstract representation it is possible to reason about transformations in a more general way and to use highly optimized linear programming libraries to figure out the optimal loop structure. These transformations can be used to do constant propagation through arrays, remove dead loop iterations, optimize loops for cache locality, optimize arrays, apply advanced automatic parallelization, drive vectorization, or they can be used to do software pipelining.