[PATCH] D110451: [IR] Increase max alignment to 4GB

[Arthur Eubanks via Phabricator via llvm-commits]

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I'll update tests/clang if this is ok with people
I can also split out the uint64_t changes


Currently the max alignment representable is 1GB, see D108661 <https://reviews.llvm.org/D108661>.
Setting the align of an object to 4GB is desirable in some cases to make sure the lower 32 bits are clear which can be used for some optimizations, e.g. https://crbug.com/1016945.

This uses an extra bit in instructions that carry an alignment. We can store 15 bits of "free" information, and with this change some instructions (e.g. AtomicCmpXchgInst) use 14 bits.
We can increase the max alignment representable above 4GB (up to 2^62) since we're only using 33 of the 64 values, but I've just limited it to 4GB for now.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D110451

Files:
  llvm/include/llvm/IR/DataLayout.h
  llvm/include/llvm/IR/GlobalObject.h
  llvm/include/llvm/IR/Instruction.h
  llvm/include/llvm/IR/Instructions.h
  llvm/include/llvm/IR/Value.h
  llvm/include/llvm/Transforms/IPO/Attributor.h
  llvm/lib/AsmParser/LLParser.cpp
  llvm/lib/CodeGen/SafeStack.cpp
  llvm/lib/IR/DataLayout.cpp
  llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
  llvm/lib/Transforms/Instrumentation/HWAddressSanitizer.cpp
  llvm/lib/Transforms/Utils/Local.cpp

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