[PATCH] D148521: [VP] Change getVPForBaseOpcode to return std::optional

[Luke Lau via Phabricator via llvm-commits]

luke added inline comments.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:937
   SDValue getNode(unsigned Opcode, const SDLoc &DL, EVT VT, SDValue Operand) {
-    unsigned VPOpcode = ISD::getVPForBaseOpcode(Opcode);
+    unsigned VPOpcode = ISD::getVPForBaseOpcode(Opcode).value();
     assert(ISD::getVPMaskIdx(VPOpcode) == 1 &&
----------------
craig.topper wrote:
> I think we're supposed to use operator* instead of value(). 
> 
> There were commits like this in December
> 
> ```
> [lldb] llvm::Optional::value() && => operator*/operator->
>     
>     std::optional::value() has undesired exception checking semantics and is
>     unavailable in older Xcode (see _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS). The
>     call sites block std::optional migration.
> ```
Good shout. Hopefully we can still use `has_value()`, I've changed it to just manually assert it.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D148521/new/

https://reviews.llvm.org/D148521