[llvm] [GlobalISel] Allow some load/store instructions to be folded in Match Table backend (PR #70830)

[Matt Arsenault via llvm-commits]

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@@ -70,6 +70,25 @@ bool GIMatchTableExecutor::isObviouslySafeToFold(MachineInstr &MI,
   if (MI.isConvergent() && MI.getParent() != IntoMI.getParent())
     return false;
 
-  return !MI.mayLoadOrStore() && !MI.mayRaiseFPException() &&
-         !MI.hasUnmodeledSideEffects() && MI.implicit_operands().empty();
+  auto IsSafe = [](const MachineInstr &MI) {
+    return !MI.mayRaiseFPException() && !MI.hasUnmodeledSideEffects() &&
+           MI.implicit_operands().empty();
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arsenm wrote:

Don't understand the implicit operands check. I think this is starting to reproduce MachineInstr::isSafeToMove

https://github.com/llvm/llvm-project/pull/70830