LGTM

LGTM

@ruiu Hi Rui, I've changed the output section order now. Can you take a look at this patch again?

Change the sorting so that .toc is emitted right after .got rather than adding it into the got.

@ruiu Hi Rui, can you please finish reviewing this?

@ruiu Hi Rui, is this okay to approve now?

In D45833#1072806, @ruiu wrote:

I wonder if you really need to merge .toc into .got. If I understand your description correctly, it doesn't matter whether they are merged or not as long as they are close enough. So I'm wondering if you can just manipulate the section output order so that .toc and .got are output next to each other.

In D45286#1058138, @jonpa wrote:

• The test could perhaps be freed of alignment, tbaa operands and dso_local specifiers, but maybe it doesn't matter. Adding Uli as reviewer since the test is in SystemZ.
• Using isImm() but not isCImm() or isFPImm() (I don't see any method like isAnyImm() available)? It seems there may be other constant operands also, like isSymbol(), but not sure if it's useful.
  
  Since it seems only PowerPC has implemented isCallerPreservedPhysReg() and are therefore the only user of this patch, I leave the review to the power-llvm-team. (Side question: Could the SP handling be put in common code?)
  
  I was actually expecting to not only look for function-constant registers via isCallerPreservedPhysReg(), but to have a set of loop-invariant phys-regs for each loop (and preheader terminators). I suppose this is not needed given that the LLVM I/R LICM pass has done most of the work, or?