[PATCH] D69101: [AIX] Refactor AIX Call Lowering to use CCState. NFCI.

Tue Oct 22 10:34:04 PDT 2019

cebowleratibm planned changes to this revision.
cebowleratibm marked 2 inline comments as done.
cebowleratibm added a comment.

I'll add some test coverage for some of the limitation errors.

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Comment at: llvm/lib/Target/PowerPC/PPCISelLowering.cpp:6818
+  const unsigned MinParameterSaveAreaSize = 8 * PtrByteSize;
+  const unsigned NumBytes = LinkageSize + MinParameterSaveAreaSize;

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sfertile wrote:
> cebowleratibm wrote:
> > sfertile wrote:
> > > You should be taking the max between `LinkageSize + MinParameterSaveAreaSize` and the stack size determined by the CCState object.
> > Agreed but the patch is meant to be NFCI and the current code doesn't support arguments on the stack so this has the same semantics as the prior code.  A future patch will address your concern.
> But `CC_AIX`  also doesn't handle arguments on the stack so IIUC the largest offset you could get back is ` LinkageSize + MinParameterSaveAreaSize` keeping this patch NFC. 
> 
> FWIW I am OK with you leaving it out for now, I don't think its worth holding up the patch over. We should have a lit tests that tests overflow args though that shows the error.
Fair enough, it would still be NFC but have the same semantic.  My intention is to correct this in a coming patch that adds support for stack arguments.  It seems to logically fit with that work.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D69101/new/

https://reviews.llvm.org/D69101