[llvm] [SandboxIR] Add more Instruction member functions (PR #98588)

[via llvm-commits]

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@@ -262,6 +262,113 @@ const char *Instruction::getOpcodeName(Opcode Opc) {
   llvm_unreachable("Unknown Opcode");
 }
 
+llvm::Instruction *Instruction::getTopmostLLVMInstruction() const {
+  Instruction *Prev = getPrevNode();
+  if (Prev == nullptr) {
+    // If at top of the BB, return the first BB instruction.
+    return &*cast<llvm::BasicBlock>(getParent()->Val)->begin();
+  }
+  // Else get the Previous sandbox IR instruction's bottom IR instruction and
+  // return its successor.
+  llvm::Instruction *PrevBotI = cast<llvm::Instruction>(Prev->Val);
+  return PrevBotI->getNextNode();
+}
+
+BBIterator Instruction::getIterator() const {
+  auto *I = cast<llvm::Instruction>(Val);
+  return BasicBlock::iterator(I->getParent(), I->getIterator(), &Ctx);
+}
+
+Instruction *Instruction::getNextNode() const {
+  assert(getParent() != nullptr && "Detached!");
+  assert(getIterator() != getParent()->end() && "Already at end!");
+  auto *LLVMI = cast<llvm::Instruction>(Val);
+  assert(LLVMI->getParent() != nullptr && "LLVM IR instr is detached!");
+  auto *NextLLVMI = LLVMI->getNextNode();
+  auto *NextI = cast_or_null<Instruction>(Ctx.getValue(NextLLVMI));
+  if (NextI == nullptr)
+    return nullptr;
+  return NextI;
+}
+
+Instruction *Instruction::getPrevNode() const {
+  assert(getParent() != nullptr && "Detached!");
+  auto It = getIterator();
+  if (It != getParent()->begin())
+    return std::prev(getIterator()).get();
+  return nullptr;
+}
+
+void Instruction::removeFromParent() {
+  // Detach all the LLVM IR instructions from their parent BB.
+  for (llvm::Instruction *I : getLLVMInstrs())
+    I->removeFromParent();
+}
+
+void Instruction::eraseFromParent() {
+  assert(users().empty() && "Still connected to users, can't erase!");
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vporpo wrote:

Did you mean `hasNUses(0)` ? Why would that be faster?  `users().empty()` should be equivalent to `user_begin() == user_end()`, which avoids the loop in `hasNUses(0). Wdyt?

https://github.com/llvm/llvm-project/pull/98588