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path: root/include/llvm/Support/Alignment.h
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2007-11-09Move MinAlign to MathExtras.h.Duncan Sands
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43944 91177308-0d34-0410-b5e6-96231b3b80d8
2007-10-28The guaranteed alignment of ptr+offset is only the minimum ofDuncan Sands
of offset and the alignment of ptr if these are both powers of 2. While the ptr alignment is guaranteed to be a power of 2, there is no reason to think that offset is. For example, if offset is 12 (the size of a long double on x86-32 linux) and the alignment of ptr is 8, then the alignment of ptr+offset will in general be 4, not 8. Introduce a function MinAlign, lifted from gcc, for computing the minimum guaranteed alignment. I've tried to fix up everywhere under lib/CodeGen/SelectionDAG/. I also changed some places that weren't wrong (because both values were a power of 2), as a defensive change against people copying and pasting the code. Hopefully someone who cares about alignment will review the rest of LLVM and fix up the remaining places. Since I'm on x86 I'm not very motivated to do this myself... git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43421 91177308-0d34-0410-b5e6-96231b3b80d8