thumb32: Implement LDMIA/LDMFD

src/frontend/A32/decoder/thumb32.inc

@@ -3,7 +3,7 @@
 //INST(thumb32_RFE_2,          "RFE",                      "1110100000-1--------------------")
 INST(thumb32_STMIA,          "STMIA/STMEA",              "1110100010W0nnnn0iiiiiiiiiiiiiii")
 //INST(thumb32_POP,            "POP",                      "1110100010111101----------------")
-//INST(thumb32_LDMIA,          "LDMIA/LDMFD",              "1110100010-1--------------------")
+INST(thumb32_LDMIA,          "LDMIA/LDMFD",              "1110100010W1nnnniiiiiiiiiiiiiiii")
 //INST(thumb32_PUSH,           "PUSH",                     "1110100100101101----------------")
 INST(thumb32_STMDB,          "STMDB/STMFD",              "1110100100W0nnnn0iiiiiiiiiiiiiii")
 //INST(thumb32_LDMDB,          "LDMDB/LDMEA",              "1110100100-1--------------------")

src/frontend/A32/translate/impl/thumb32_load_store_multiple.cpp

@@ -7,6 +7,59 @@
 #include "frontend/A32/translate/impl/translate_thumb.h"
 
 namespace Dynarmic::A32 {
+static bool ITBlockCheck(const A32::IREmitter& ir) {
+    return ir.current_location.IT().IsInITBlock() && !ir.current_location.IT().IsLastInITBlock();
+}
+
+static bool LDMHelper(A32::IREmitter& ir, bool W, Reg n, u32 list,
+                      const IR::U32& start_address, const IR::U32& writeback_address) {
+    auto address = start_address;
+    for (size_t i = 0; i <= 14; i++) {
+        if (Common::Bit(i, list)) {
+            ir.SetRegister(static_cast<Reg>(i), ir.ReadMemory32(address));
+            address = ir.Add(address, ir.Imm32(4));
+        }
+    }
+    if (W && !Common::Bit(RegNumber(n), list)) {
+        ir.SetRegister(n, writeback_address);
+    }
+    if (Common::Bit<15>(list)) {
+        ir.UpdateUpperLocationDescriptor();
+        ir.LoadWritePC(ir.ReadMemory32(address));
+        if (n == Reg::R13) {
+            ir.SetTerm(IR::Term::PopRSBHint{});
+        } else {
+            ir.SetTerm(IR::Term::FastDispatchHint{});
+        }
+        return false;
+    }
+    return true;
+}
+
+bool ThumbTranslatorVisitor::thumb32_LDMIA(bool W, Reg n, Imm<16> reg_list) {
+    const auto regs_imm = reg_list.ZeroExtend();
+    const auto num_regs = static_cast<u32>(Common::BitCount(regs_imm));
+
+    if (n == Reg::PC || num_regs < 2) {
+        return UnpredictableInstruction();
+    }
+    if (reg_list.Bit<15>() && reg_list.Bit<14>()) {
+        return UnpredictableInstruction();
+    }
+    if (W && Common::Bit(static_cast<size_t>(n), regs_imm)) {
+        return UnpredictableInstruction();
+    }
+    if (reg_list.Bit<13>()) {
+        return UnpredictableInstruction();
+    }
+    if (reg_list.Bit<15>() && ITBlockCheck(ir)) {
+        return UnpredictableInstruction();
+    }
+
+    const auto start_address = ir.GetRegister(n);
+    const auto writeback_address = ir.Add(start_address, ir.Imm32(num_regs * 4));
+    return LDMHelper(ir, W, n, regs_imm, start_address, writeback_address);
+}
 
 bool ThumbTranslatorVisitor::thumb32_STMIA(bool W, Reg n, Imm<15> reg_list) {
     const auto regs_imm = reg_list.ZeroExtend();

src/frontend/A32/translate/impl/translate_thumb.h

@@ -172,6 +172,7 @@ struct ThumbTranslatorVisitor final {
     bool thumb16_B_t2(Imm<11> imm11);
 
     // thumb32 load/store multiple instructions
+    bool thumb32_LDMIA(bool W, Reg n, Imm<16> reg_list);
     bool thumb32_STMIA(bool W, Reg n, Imm<15> reg_list);
     bool thumb32_STMDB(bool W, Reg n, Imm<15> reg_list);