[clang] [Clang][SME2] Add single and multi min and max builtins (PR #71688)

[Kerry McLaughlin via cfe-commits]

================
@@ -1987,8 +1987,26 @@ defm SVREVD : SInstZPZ<"svrevd", "csilUcUsUiUl", "aarch64_sve_revd">;
 // SME intrinsics which operate only on vectors and do not require ZA should be added here,
 // as they could possibly become SVE instructions in the future.
 
+multiclass MinMaxIntr<string i, string zm, string mul, string t> {
+  def SVS # NAME : SInst<"sv" # i # "[" # zm # "_{d}_" # mul # "]", t, "csil",     MergeNone, "aarch64_sve_s" # i # zm # "_" # mul, [IsStreaming], []>;
+  def SVU # NAME : SInst<"sv" # i # "[" # zm # "_{d}_" # mul # "]", t, "UcUsUiUl", MergeNone, "aarch64_sve_u" # i # zm # "_" # mul, [IsStreaming], []>;
+  def SVF # NAME : SInst<"sv" # i # "[" # zm # "_{d}_" # mul # "]", t, "hfd",      MergeNone, "aarch64_sve_f" # i # zm # "_" # mul, [IsStreaming], []>;
+}
+
 let TargetGuard = "sme2" in {
 // == ADD (vectors) ==
   def SVADD_SINGLE_X2 : SInst<"svadd[_single_{d}_x2]", "22d", "cUcsUsiUilUl", MergeNone, "aarch64_sve_add_single_x2", [IsStreaming], []>;
   def SVADD_SINGLE_X4 : SInst<"svadd[_single_{d}_x4]", "44d", "cUcsUsiUilUl", MergeNone, "aarch64_sve_add_single_x4", [IsStreaming], []>;
+
+// == SMAX / UMAX / FMAX ==
+  defm MAX_SINGLE_X2 : MinMaxIntr<"max", "_single", "x2", "22d">;
+  defm MAX_MULTI_X2  : MinMaxIntr<"max", "",        "x2", "222">;
+  defm MAX_SINGLE_X4 : MinMaxIntr<"max", "_single", "x4", "44d">;
+  defm MAX_MULTI_X4  : MinMaxIntr<"max", "",        "x4", "444">;
+
+// == SMIN / UMIN / FMIN ==
+  defm MIN_SINGLE_X2 : MinMaxIntr<"min", "_single", "x2", "22d">;
+  defm MIN_MULTI_X2  : MinMaxIntr<"min", "",        "x2", "222">;
+  defm MIN_SINGLE_X4 : MinMaxIntr<"min", "_single", "x4", "44d">;
+  defm MIN_MULTI_X4  : MinMaxIntr<"min", "",        "x4", "444">;
----------------
kmclaughlin-arm wrote:

This is just a suggestion, but I think it could be worth adding the definitions that use a multiclass separately from this `let TargetGuard = "sme2"` block. I find it quite useful to have the multiclasses close to the definitions that use them when reading how the builtins are defined, and when more are added here this could become harder to follow.

https://github.com/llvm/llvm-project/pull/71688