[AArch64] Handle XAR with v1i64 operand types

When converting ROTR(XOR(a, b)) to XAR(a, b), or ROTR(a, a) to XAR(a, zero) we
were not handling v1i64 types, meaning illegal copies get generated. This
addresses that by generating insert_subreg and extract_subreg for v1i64 types
to keep the values with the correct types.

Fixes #141746

Author: davemgreen

llvm/lib/Target/AArch64/AArch64ISelDAGToDAG.cpp

@@ -4637,15 +4637,39 @@ bool AArch64DAGToDAGISel::trySelectXAR(SDNode *N) {
 
   if (!IsXOROperand) {
     SDValue Zero = CurDAG->getTargetConstant(0, DL, MVT::i64);
-    SDNode *MOV = CurDAG->getMachineNode(AArch64::MOVIv2d_ns, DL, VT, Zero);
+    SDNode *MOV =
+        CurDAG->getMachineNode(AArch64::MOVIv2d_ns, DL, MVT::v2i64, Zero);
     SDValue MOVIV = SDValue(MOV, 0);
     R1 = N1->getOperand(0);
     R2 = MOVIV;
   }
 
+  // If the input is a v1i64, widen to a v2i64 to use XAR.
+  assert((VT == MVT::v1i64 || VT == MVT::v2i64) && "Unexpected XAR type!");
+  if (VT == MVT::v1i64) {
+    EVT SVT = MVT::v2i64;
+    SDValue Undef =
+        SDValue(CurDAG->getMachineNode(AArch64::IMPLICIT_DEF, DL, SVT), 0);
+    SDValue DSub = CurDAG->getTargetConstant(AArch64::dsub, DL, MVT::i32);
+    R1 = SDValue(CurDAG->getMachineNode(AArch64::INSERT_SUBREG, DL, SVT, Undef,
+                                        R1, DSub),
+                 0);
+    if (R2.getValueType() == MVT::v1i64)
+      R2 = SDValue(CurDAG->getMachineNode(AArch64::INSERT_SUBREG, DL, SVT,
+                                          Undef, R2, DSub),
+                   0);
+  }
+
   SDValue Ops[] = {R1, R2, Imm};
-  CurDAG->SelectNodeTo(N, AArch64::XAR, N0.getValueType(), Ops);
+  SDNode *XAR =
+      CurDAG->getMachineNode(AArch64::XAR, DL, R1.getValueType(), Ops);
 
+  if (VT == MVT::v1i64) {
+    SDValue DSub = CurDAG->getTargetConstant(AArch64::dsub, DL, MVT::i32);
+    XAR = CurDAG->getMachineNode(AArch64::EXTRACT_SUBREG, DL, VT,
+                                 SDValue(XAR, 0), DSub);
+  }
+  ReplaceNode(N, XAR);
   return true;
 }
 

llvm/test/CodeGen/AArch64/xar.ll

@@ -19,6 +19,26 @@ define <2 x i64> @xar(<2 x i64> %x, <2 x i64> %y) {
     ret <2 x i64> %b
 }
 
+define <1 x i64> @xar_v1i64(<1 x i64> %a, <1 x i64> %b) {
+; SHA3-LABEL: xar_v1i64:
+; SHA3:       // %bb.0:
+; SHA3-NEXT:    // kill: def $d0 killed $d0 def $q0
+; SHA3-NEXT:    // kill: def $d1 killed $d1 def $q1
+; SHA3-NEXT:    xar v0.2d, v0.2d, v1.2d, #63
+; SHA3-NEXT:    // kill: def $d0 killed $d0 killed $q0
+; SHA3-NEXT:    ret
+;
+; NOSHA3-LABEL: xar_v1i64:
+; NOSHA3:       // %bb.0:
+; NOSHA3-NEXT:    eor v1.8b, v0.8b, v1.8b
+; NOSHA3-NEXT:    shl d0, d1, #1
+; NOSHA3-NEXT:    usra d0, d1, #63
+; NOSHA3-NEXT:    ret
+  %v.val = xor <1 x i64> %a, %b
+  %fshl = tail call <1 x i64> @llvm.fshl.v1i64(<1 x i64> %v.val, <1 x i64> %v.val, <1 x i64> splat (i64 1))
+  ret <1 x i64> %fshl
+}
+
 define <2 x i64> @xar_instead_of_or1(<2 x i64> %r) {
 ; SHA3-LABEL: xar_instead_of_or1:
 ; SHA3:       // %bb.0: // %entry
@@ -37,6 +57,25 @@ entry:
   ret <2 x i64> %or
 }
 
+define <1 x i64> @xar_instead_of_or_v1i64(<1 x i64> %v.val) {
+; SHA3-LABEL: xar_instead_of_or_v1i64:
+; SHA3:       // %bb.0:
+; SHA3-NEXT:    movi v1.2d, #0000000000000000
+; SHA3-NEXT:    // kill: def $d0 killed $d0 def $q0
+; SHA3-NEXT:    xar v0.2d, v0.2d, v1.2d, #63
+; SHA3-NEXT:    // kill: def $d0 killed $d0 killed $q0
+; SHA3-NEXT:    ret
+;
+; NOSHA3-LABEL: xar_instead_of_or_v1i64:
+; NOSHA3:       // %bb.0:
+; NOSHA3-NEXT:    shl d1, d0, #1
+; NOSHA3-NEXT:    usra d1, d0, #63
+; NOSHA3-NEXT:    fmov d0, d1
+; NOSHA3-NEXT:    ret
+  %fshl = tail call <1 x i64> @llvm.fshl.v1i64(<1 x i64> %v.val, <1 x i64> %v.val, <1 x i64> splat (i64 1))
+  ret <1 x i64> %fshl
+}
+
 define <4 x i32> @xar_instead_of_or2(<4 x i32> %r) {
 ; SHA3-LABEL: xar_instead_of_or2:
 ; SHA3:       // %bb.0: // %entry