[PATCH] D140160: [llvm][SelectionDAGBuilder] codegen callbr.landingpad intrinsic

Wed Jan 25 11:03:21 PST 2023

nickdesaulniers added inline comments.

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Comment at: llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp:44

+static bool isUsedOutsideOfDefiningBlock(const CallBrInst *CBR) {
+  return llvm::any_of(CBR->getIndirectDests(), [](BasicBlock *Dest) {
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jyknight wrote:
> It's unfortunate to need to special case this. Perhaps the intrinsic should take the callbr's output value as an input -- instead of magically "poofing" its value into existence by looking at the terminating instruction of the predecessor block? Then this code could be deleted, I believe.
I designed the intrinsic this way because of this comment by @efriedma : https://reviews.llvm.org/D139565#inline-1347398

>> Having the callbr as an operand seems redundant. We can already look up the corresponding callbr by just grabbing the terminator of the predecessor.

I might still have a prototype in a local branch that does have the explicit operand and uses an intrinsic rather than instruction, so it's probably not too bad to resurrect that code.  I don't feel very strongly either way.

But I would like @efriedma to review @jyknight 's point above, since rewriting the tests is exhausting, and I would need to revise this patch and the two prior. @efriedma thoughts?

Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D140160/new/

https://reviews.llvm.org/D140160