[llvm] [llvm][NFC] Refactor AutoUpgrader arm/aarch64 (PR #74145)

[Nikita Popov via llvm-commits]

================
@@ -621,6 +621,318 @@ static bool UpgradeX86IntrinsicFunction(Function *F, StringRef Name,
   return false;
 }
 
+// Upgrade ARM (IsArm) or Aarch64 (!IsArm) intrinsic fns. Return true iff so.
+// IsArm: 'arm.*', !IsArm: 'aarch64.*'.
+static bool UpgradeArmOrAarch64IntrinsicFunction(bool IsArm, Function *F,
+                                                 StringRef Name,
+                                                 Function *&NewFn) {
+  if (Name.starts_with("rbit")) {
+    // '(arm|aarch64).rbit'.
+    NewFn = Intrinsic::getDeclaration(F->getParent(), Intrinsic::bitreverse,
+                                      F->arg_begin()->getType());
+    return true;
+  }
+
+  if (Name == "thread.pointer") {
+    // '(arm|aarch64).thread.pointer'.
+    NewFn =
+        Intrinsic::getDeclaration(F->getParent(), Intrinsic::thread_pointer);
+    return true;
+  }
+
+  bool Neon = Name.consume_front("neon.");
+  if (Neon) {
+    // '(arm|aarch64).neon.*'.
+    // Changed in 12.0: bfdot accept v4bf16 and v8bf16 instead of v8i8 and
+    // v16i8 respectively.
+    if (Name.consume_front("bfdot.")) {
+      // (arm|aarch64).neon.bfdot.*'.
+      Intrinsic::ID ID = StringSwitch<Intrinsic::ID>(Name)
+                             .Cases("v2f32.v8i8", "v4f32.v16i8",
+                                    IsArm ? Intrinsic::arm_neon_bfdot
+                                          : Intrinsic::aarch64_neon_bfdot)
+                             .Default(Intrinsic::not_intrinsic);
+      if (ID != Intrinsic::not_intrinsic) {
+        size_t OperandWidth = F->getReturnType()->getPrimitiveSizeInBits();
+        assert((OperandWidth == 64 || OperandWidth == 128) &&
+               "Unexpected operand width");
+        LLVMContext &Ctx = F->getParent()->getContext();
+        std::array<Type *, 2> Tys{
+            {F->getReturnType(),
+             FixedVectorType::get(Type::getBFloatTy(Ctx), OperandWidth / 16)}};
+        NewFn = Intrinsic::getDeclaration(F->getParent(), ID, Tys);
+        return true;
+      }
+      return false; // No other '(arm|aarch64).neon.bfdot.*'.
+    }
+
+    // Changed in 12.0: bfmmla, bfmlalb and bfmlalt are not polymorphic
+    // anymore and accept v8bf16 instead of v16i8.
+    if (Name.consume_front("bfm")) {
+      // (arm|aarch64).neon.bfm*'.
+      if (Name.consume_back(".v4f32.v16i8")) {
+        // (arm|aarch64).neon.bfm*.v4f32.v16i8'.
+        Intrinsic::ID ID =
+            StringSwitch<Intrinsic::ID>(Name)
+                .Case("mla", IsArm ? Intrinsic::arm_neon_bfmmla
+                                   : Intrinsic::aarch64_neon_bfmmla)
+                .Case("lalb", IsArm ? Intrinsic::arm_neon_bfmlalb
+                                    : Intrinsic::aarch64_neon_bfmlalb)
+                .Case("lalt", IsArm ? Intrinsic::arm_neon_bfmlalt
+                                    : Intrinsic::aarch64_neon_bfmlalt)
+                .Default(Intrinsic::not_intrinsic);
+        if (ID != Intrinsic::not_intrinsic) {
+          std::array<Type *, 0> Tys;
+          NewFn = Intrinsic::getDeclaration(F->getParent(), ID, Tys);
+          return true;
+        }
+        return false; // No other '(arm|aarch64).neon.bfm*.v16i8'.
+      }
+      return false; // No other '(arm|aarch64).neon.bfm*.
+    }
+    // Continue on to Aarch64 Neon or Arm Neon.
+  }
+  // Continue on to Arm or Aarch64.
+
+  if (IsArm) {
+    // 'arm.*'.
+    if (Neon) {
+      // 'arm.neon.*'.
+      if (Name.consume_front("vclz.")) {
+        // 'arm.neon.vclz.*'.
+        Type *args[2] = {F->arg_begin()->getType(),
+                         Type::getInt1Ty(F->getContext())};
+        // Can't use Intrinsic::getDeclaration here as it adds a ".i1" to
+        // the end of the name. Change name from 'llvm.arm.neon.vclz.*' to
+        //  'llvm.ctlz.*'.
----------------
nikic wrote:

This comment is incorrect. Switched to Intrinsic::getDeclaration in https://github.com/llvm/llvm-project/commit/e309667769c8f7d6f5616c226ee43a19dcee8bf3.

https://github.com/llvm/llvm-project/pull/74145