[llvm] [GlobalISel] Import extract/insert subvector (PR #110287)

[Thorsten Schütt via llvm-commits]

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@@ -3163,6 +3167,58 @@ bool IRTranslator::translateInsertElement(const User &U,
   return true;
 }
 
+bool IRTranslator::translateInsertVector(const User &U,
+                                         MachineIRBuilder &MIRBuilder) {
+  Register Dst = getOrCreateVReg(U);
+  Register Vec = getOrCreateVReg(*U.getOperand(0));
+  Register Elt = getOrCreateVReg(*U.getOperand(1));
+
+  ConstantInt *CI = cast<ConstantInt>(U.getOperand(2));
+  unsigned PreferredVecIdxWidth = TLI->getVectorIdxTy(*DL).getSizeInBits();
+
+  // Resize Index to preferred index width.
+  if (CI->getBitWidth() != PreferredVecIdxWidth) {
+    APInt NewIdx = CI->getValue().zextOrTrunc(PreferredVecIdxWidth);
+    CI = ConstantInt::get(CI->getContext(), NewIdx);
+  }
+
+  // If it is a <1 x Ty> vector, we have to use other means.
+  if (auto *ResultType = dyn_cast<FixedVectorType>(U.getOperand(1)->getType());
+      ResultType && ResultType->getNumElements() == 1) {
+    if (auto *InputType = dyn_cast<FixedVectorType>(U.getOperand(0)->getType());
+        InputType && InputType->getNumElements() == 1) {
+      // We are inserting an illegal fixed vector into an illegal
+      // fixed vector, use the scalar as it is not a legal vector type
+      // in LLT.
+      return translateCopy(U, *U.getOperand(0), MIRBuilder);
+    }
+    if (auto *InputType =
+            dyn_cast<FixedVectorType>(U.getOperand(0)->getType())) {
+      // We are inserting an illegal fixed vector into a fixed vector, use the
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tschuett wrote:

Nope. It is meant to say `InputType && InputType->getNumElements() != 1`.

https://github.com/llvm/llvm-project/pull/110287