yamauchi added inline comments.
================ Comment at: llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp:623 // Compute Hash value for the CFG: the lower 32 bits are CRC32 of the index -// value of each BB in the CFG. The higher 32 bits record the number of edges. +// value of each BB in the CFG. The higher 32 bits are the CR32 of the numbers +// of selects, indirect calls, mem ops and edges. ---------------- MaskRay wrote: > To make sure I understand: we use two CRCs instead of one CRC because we want > to extract low/high 32 bits for debugging purposes? > > Otherwise, we can just use one CRC. JamCRC's result is 32-bit, but we have 64-bit (actually 60-bits) of spare room. Using more bits should decrease the chance of hash collisions. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D84782/new/ https://reviews.llvm.org/D84782 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
