[clang] [llvm] [Clang][SME2] Add builtins for moving multi-vectors to/from ZA (PR #71191)

[David Sherwood via cfe-commits]

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@@ -299,6 +299,44 @@ multiclass ZAAddSub<string n_suffix> {
 defm SVADD : ZAAddSub<"add">;
 defm SVSUB : ZAAddSub<"sub">;
 
+// SME2 - MOVA
+
+//
+// Single, 2 and 4 vector-group read/write intrinsics.
+//
+
+multiclass ZAWrite_VG<string n, string t, string i, list<ImmCheck> checks> {
+  def NAME # _VG2_H : Inst<"svwrite_hor_" # n # "_vg2",   "vim2", t, MergeNone, i # "_hor_vg2", [IsSharedZA, IsStreaming], checks>;
+  def NAME # _VG2_V : Inst<"svwrite_ver_" # n # "_vg2",   "vim2", t, MergeNone, i # "_ver_vg2", [IsSharedZA, IsStreaming], checks>;
+  def NAME # _VG4_H : Inst<"svwrite_hor_" # n # "_vg4",   "vim4", t, MergeNone, i # "_hor_vg4", [IsSharedZA, IsStreaming], checks>;
+  def NAME # _VG4_V : Inst<"svwrite_ver_" # n # "_vg4",   "vim4", t, MergeNone, i # "_ver_vg4", [IsSharedZA, IsStreaming], checks>;
+  def NAME # _VG1x2 : Inst<"svwrite_"     # n # "_vg1x2", "vm2",  t, MergeNone, i # "_vg1x2",   [IsSharedZA, IsStreaming], []>;
+  def NAME # _VG1x4 : Inst<"svwrite_"     # n # "_vg1x4", "vm4",  t, MergeNone, i # "_vg1x4",   [IsSharedZA, IsStreaming], []>;
+}
+
+let TargetGuard = "sme2" in {
+  defm SVWRITE_ZA8  : ZAWrite_VG<"za8[_{d}]",  "cUc",   "aarch64_sme_write", [ImmCheck<0, ImmCheck0_0>]>;
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david-arm wrote:

This is just a thought - is it worth pushing the `"[_{d}]"` bit into the multiclass given it's the same for each size, i.e.

```
  def NAME # _VG2_H : Inst<"svwrite_hor_" # n # "[_{d}]_vg2",   "vim2", t, MergeNone, i # "_hor_vg2", [IsSharedZA, IsStreaming], checks>;
```

and same question for the reads.

https://github.com/llvm/llvm-project/pull/71191