Change Details

In this patch `Value::getPointerDereferenceableBytes` and `Value::getPointerAlignment` are extracted into more powerful versions living alongside `isDereferenceableAndAlignedPointer` in `Analysis/Loads.h`. The functions have also been enriched wrt. GEP support and unified wrt. value kinds they can unpack. Thus, the only "new" logic is concerned with GEP handling everything else is copied/moved from other places. NOTE: One caveat is that at least one use site (ConstantFold.cpp) does not have access to the analysis library in which the functions now live. NOTE: Changes to downstream code should be mechanical, I used: %s/\(\w\+\)->getPointerAlignment(/getPointerAlignment(\1, / NOTE: Not all affected tests have been updated but only one to show how the improved GEP logic affects alignment.

NOTE: This is a prototype to show an alternative to the two solutionssketched in http://lists.llvm.org/pipermail/llvm-dev/2019-August/134680.html . In this patch `Value::getPointerDereferenceableBytes` and `Value::getPointerAlignment` are extracted into more powerful versions living alongside `isDereferenceableAndAlignedPointer` in `Analysis/Loads.h`. The functions have also been enriched wrt. GEP support and unified wrt. value kinds they can unpack. Thus, the only "new" logic is concerned with GEP handling everything else is copied/moved from other places. NOTE: One caveat is that at least one use site (ConstantFold.cpp) does not have access to the analysis library in which the functions now live. NOTE: Changes to downstream code should be mechanical, I used: %s/\(\w\+\)->getPointerAlignment(/getPointerAlignment(\1, / NOTE: Not all affected tests have been updated but only one to show how the improved GEP logic affects alignment.

NOTE: This is a prototype to show an alternative to the two solutionssketched in http://lists.llvm.org/pipermail/llvm-dev/2019-August/134680.html . In this patch `Value::getPointerDereferenceableBytes` and `Value::getPointerAlignment` are extracted into more powerful versions living alongside `isDereferenceableAndAlignedPointer` in `Analysis/Loads.h`. The functions have also been enriched wrt. GEP support and unified wrt. value kinds they can unpack. Thus, the only "new" logic is concerned with GEP handling everything else is copied/moved from other places. NOTE: One caveat is that at least one use site (ConstantFold.cpp) does not have access to the analysis library in which the functions now live. NOTE: Changes to downstream code should be mechanical, I used: %s/\(\w\+\)->getPointerAlignment(/getPointerAlignment(\1, / NOTE: Not all affected tests have been updated but only one to show how the improved GEP logic affects alignment.