A64: Implement SIMD instruction SHL

src/frontend/A64/translate/impl/simd_shift_by_immediate.cpp

@@ -0,0 +1,43 @@
+/* This file is part of the dynarmic project.
+ * Copyright (c) 2018 MerryMage
+ * This software may be used and distributed according to the terms of the GNU
+ * General Public License version 2 or any later version.
+ */
+
+#include "common/bit_util.h"
+#include "frontend/A64/translate/impl/impl.h"
+
+namespace Dynarmic::A64 {
+
+bool TranslatorVisitor::SHL_2(bool Q, Imm<4> immh, Imm<3> immb, Vec Vn, Vec Vd) {
+    if (immh == 0b0000) {
+        return DecodeError();
+    }
+    if (immh.Bit<3>() && !Q) {
+        return ReservedValue();
+    }
+    const size_t esize = 8 << Common::HighestSetBit(immh.ZeroExtend());
+    const size_t datasize = Q ? 128 : 64;
+
+    const u8 shift_amount = concatenate(immh, immb).ZeroExtend<u8>() - static_cast<u8>(esize);
+
+    const IR::U128 operand = V(datasize, Vn);
+    const IR::U128 result = [&]{
+        switch (esize) {
+        case 8:
+            return ir.VectorLogicalShiftLeft8(operand, shift_amount);
+        case 16:
+            return ir.VectorLogicalShiftLeft16(operand, shift_amount);
+        case 32:
+            return ir.VectorLogicalShiftLeft32(operand, shift_amount);
+        case 64:
+        default:
+            return ir.VectorLogicalShiftLeft64(operand, shift_amount);
+        }
+    }();
+
+    V(datasize, Vd, result);
+    return true;
+}
+
+} // namespace Dynarmic::A64