[PATCH] D89978: Fix SROA with a constant value PHI

[Eli Friedman via Phabricator via llvm-commits]

efriedma added inline comments.


================
Comment at: llvm/lib/Transforms/Scalar/SROA.cpp:3527
     PHINode *PHI = cast<PHINode>(GEPI.getPointerOperand());
-    if (GEPI.getParent() != PHI->getParent() ||
+    if (GEPI.getParent() != PHI->getParent() || PHI->hasConstantValue() ||
         llvm::any_of(PHI->incoming_values(), [](Value *In)
----------------
rampitec wrote:
> efriedma wrote:
> > I don't think that's what you want to check.  In particular, it doesn't handle the case where a block has multiple predecessors containing a construct like `br i1 undef, label %cond.end.i, label %cond.end.i` (or more commonly, a switch).
> Do you mean it is legal to have several incoming values from a same block and then some from another?
Yes.  For example, https://godbolt.org/z/6b86Ts .


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D89978/new/

https://reviews.llvm.org/D89978