[llvm] [X86] LowerShift - don't prematurely lower to x86 vector shift imm instructions (PR #120282)

[Phoebe Wang via llvm-commits]

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@@ -30100,10 +30100,10 @@ static SDValue LowerShift(SDValue Op, const X86Subtarget &Subtarget,
       auto *Cst2 = dyn_cast<ConstantSDNode>(Amt2);
       if (Cst1 && Cst2 && Cst1->getAPIntValue().ult(EltSizeInBits) &&
           Cst2->getAPIntValue().ult(EltSizeInBits)) {
-        SDValue Shift1 = getTargetVShiftByConstNode(X86OpcI, dl, VT, R,
-                                                    Cst1->getZExtValue(), DAG);
-        SDValue Shift2 = getTargetVShiftByConstNode(X86OpcI, dl, VT, R,
-                                                    Cst2->getZExtValue(), DAG);
+        SDValue Shift1 = DAG.getNode(
+            Opc, dl, VT, R, DAG.getConstant(Cst1->getZExtValue(), dl, VT));
+        SDValue Shift2 = DAG.getNode(
+            Opc, dl, VT, R, DAG.getConstant(Cst2->getZExtValue(), dl, VT));
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phoebewang wrote:

Is this undef safe? Or we don't need to consider it?

https://github.com/llvm/llvm-project/pull/120282