[llvm] [AArch64][SME2] Add FORM_STRIDED_TUPLE pseudo nodes (PR #116399)

[Kerry McLaughlin via llvm-commits]

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@@ -174,6 +188,12 @@ class SME2_ZA_TwoOp_VG2_Multi_Index_Pat<string name, SDPatternOperator intrinsic
           (!cast<Instruction>(name # _PSEUDO) $base, $offset,
                                               (REG_SEQUENCE ZPR2Mul2, vt:$Zn1, zsub0, vt:$Zn2, zsub1), zpr_ty:$Zm, imm_ty:$i)>;
 
+class SME2_ZA_TwoOp_VG2_Multi_Index_FormStrided_Pat<string name, SDPatternOperator intrinsic, Operand index_ty, ZPRRegOp zpr_ty, ValueType vt,
+                                        Operand imm_ty, ComplexPattern tileslice>
+    : Pat<(intrinsic (i32 (tileslice MatrixIndexGPR32Op8_11:$base, index_ty:$offset)), vt:$Zn1, vt:$Zn2, vt:$Zm, (i32 imm_ty:$i)),
+          (!cast<Instruction>(name # _PSEUDO) $base, $offset,
+                                              (FORM_STRIDED_TUPLE_X2_PSEUDO vt:$Zn1,vt:$Zn2), zpr_ty:$Zm, imm_ty:$i)>;
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kmclaughlin-arm wrote:

There are a number of other intrinsics which use these patterns other than sdot/udot, which is why I initially added a new pattern. However, since we will fall back on REG_SEQUENCE anyway if the expected copy instructions are not found I think we can just update the existing one.

https://github.com/llvm/llvm-project/pull/116399