A64: Implement SBFM, BFM, UBFM

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

@@ -0,0 +1,81 @@
+/* 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 "frontend/A64/translate/impl/impl.h"
+
+namespace Dynarmic {
+namespace A64 {
+
+static IR::U32U64 ReplicateBit(IREmitter& ir, const IR::U32U64& value, u8 bit_position_to_replicate) {
+    u8 datasize = value.GetType() == IR::Type::U64 ? 64 : 32;
+    auto bit = ir.LogicalShiftLeft(value, ir.Imm8(datasize - 1 - bit_position_to_replicate));
+    return ir.ArithmeticShiftRight(bit, ir.Imm8(datasize - 1));
+}
+
+bool TranslatorVisitor::SBFM(bool sf, bool N, Imm<6> immr, Imm<6> imms, Reg Rn, Reg Rd) {
+    size_t datasize = sf ? 64 : 32;
+
+    if (sf && !N) return ReservedValue();
+    if (!sf && (N || immr.Bit<5>() || imms.Bit<5>())) return ReservedValue();
+
+    u8 R = immr.ZeroExtend<u8>();
+    u8 S = imms.ZeroExtend<u8>();
+    auto masks = DecodeBitMasks(N, imms, immr, false);
+    if (!masks) return ReservedValue();
+
+    auto src = X(datasize, Rn);
+
+    auto bot = ir.And(ir.RotateRight(src, ir.Imm8(R)), I(datasize, masks->wmask));
+    auto top = ReplicateBit(ir, src, S);
+
+    top = ir.And(top, I(datasize, ~masks->tmask));
+    bot = ir.And(bot, I(datasize, masks->tmask));
+    X(datasize, Rd, ir.Or(top, bot));
+
+    return true;
+}
+
+bool TranslatorVisitor::BFM(bool sf, bool N, Imm<6> immr, Imm<6> imms, Reg Rn, Reg Rd) {
+    size_t datasize = sf ? 64 : 32;
+
+    if (sf && !N) return ReservedValue();
+    if (!sf && (N || immr.Bit<5>() || imms.Bit<5>())) return ReservedValue();
+
+    u8 R = immr.ZeroExtend<u8>();
+    auto masks = DecodeBitMasks(N, imms, immr, false);
+    if (!masks) return ReservedValue();
+
+    auto dst = X(datasize, Rd);
+    auto src = X(datasize, Rn);
+
+    auto bot = ir.Or(ir.And(dst, I(datasize, ~masks->wmask)), ir.And(ir.RotateRight(src, ir.Imm8(R)), I(datasize, masks->wmask)));
+
+    X(datasize, Rd, ir.Or(ir.And(dst, I(datasize, ~masks->tmask)), ir.And(bot, I(datasize, masks->tmask))));
+
+    return true;
+}
+
+bool TranslatorVisitor::UBFM(bool sf, bool N, Imm<6> immr, Imm<6> imms, Reg Rn, Reg Rd) {
+    size_t datasize = sf ? 64 : 32;
+
+    if (sf && !N) return ReservedValue();
+    if (!sf && (N || immr.Bit<5>() || imms.Bit<5>())) return ReservedValue();
+
+    u8 R = immr.ZeroExtend<u8>();
+    auto masks = DecodeBitMasks(N, imms, immr, false);
+    if (!masks) return ReservedValue();
+
+    auto src = X(datasize, Rn);
+
+    auto bot = ir.And(ir.RotateRight(src, ir.Imm8(R)), I(datasize, masks->wmask));
+
+    X(datasize, Rd, ir.And(bot, I(datasize, masks->tmask)));
+
+    return true;
+}
+
+} // namespace A64
+} // namespace Dynarmic