WIP 2 SingleDataTransfer

Former-commit-id: 8a103161f34eb1a6c731c63ae65ca1056117ec55
Former-commit-id: 74c8158e7354253f6bd4ad50488d34de34e3ad70

core/build.rs

@@ -162,7 +162,17 @@ fn arm_decode(i: u32) -> String {
         }
         0b01 => {
             match (i.bit(25), i.bit(4)) {
-                (_, F) | (F, T) => String::from("exec_arm_ldr_str"),
+                (_, F) | (F, T) => format!(
+                    "exec_arm_ldr_str::<{LOAD}, {WRITEBACK}, {PRE_INDEX}, {BYTE}, {SHIFT}, {ADD}, {BS_OP}, {SHIFT_BY_REG}>",
+                    LOAD = i.bit(20),
+                    WRITEBACK = i.bit(21),
+                    BYTE = i.bit(22),
+                    ADD = i.bit(23),
+                    PRE_INDEX = i.bit(24),
+                    SHIFT = i.bit(25),
+                    BS_OP = i.bit_range(5..7) as u8,
+                    SHIFT_BY_REG = i.bit(4),
+                ),
                 (T, T) => String::from("arm_undefined"), /* Possible ARM11 but we don't implement these */
             }
         }

core/src/arm7tdmi/alu.rs

@@ -261,6 +261,28 @@ impl<I: MemoryInterface> Core<I> {
         self.barrel_shift_op(bs_op, val, amount, carry, false)
     }
 
+    pub fn register_shift_const<const BS_OP: u8, const SHIFT_BY_REG: bool>(
+        &mut self,
+        offset: u32,
+        reg: usize,
+        carry: &mut bool,
+    ) -> u32 {
+        let op = match BS_OP {
+            0 => BarrelShiftOpCode::LSL,
+            1 => BarrelShiftOpCode::LSR,
+            2 => BarrelShiftOpCode::ASR,
+            3 => BarrelShiftOpCode::ROR,
+            _ => unreachable!(),
+        };
+        if SHIFT_BY_REG {
+            let rs = offset.bit_range(8..12) as usize;
+            self.shift_by_register(op, reg, rs, carry)
+        } else {
+            let amount = offset.bit_range(7..12) as u32;
+            self.barrel_shift_op(op, self.get_reg(reg), amount, carry, true)
+        }
+    }
+
     pub fn register_shift(&mut self, shift: &ShiftedRegister, carry: &mut bool) -> u32 {
         match shift.shift_by {
             ShiftRegisterBy::ByAmount(amount) => {

core/src/arm7tdmi/arm/exec.rs

@@ -185,8 +185,6 @@ impl<I: MemoryInterface> Core<I> {
         let opcode =
             AluOpCode::from_u8(OP).unwrap_or_else(|| unsafe { std::hint::unreachable_unchecked() });
 
-        // println!("{:?} {} {} {}, {:?} {} {} {}", insn.opcode(), insn.bit(25), insn.set_cond_flags(), insn.bit(4), opcode, IMM, SET_FLAGS, SHIFT_BY_REG);
-
         let mut carry = self.cpsr.C();
         let op2 = if IMM {
             let immediate = insn & 0xff;
@@ -288,37 +286,51 @@ impl<I: MemoryInterface> Core<I> {
     /// STR{cond}{B}{T} Rd,<Address>    | 2N            | ----  |  [Rn+/-<offset>]=Rd
     /// ------------------------------------------------------------------------------
     /// For LDR, add y=1S+1N if Rd=R15.
-    pub fn exec_arm_ldr_str(&mut self, insn: u32) -> CpuAction {
+    pub fn exec_arm_ldr_str<
+        const LOAD: bool,
+        const WRITEBACK: bool,
+        const PRE_INDEX: bool,
+        const BYTE: bool,
+        const SHIFT: bool,
+        const ADD: bool,
+        const BS_OP: u8,
+        const SHIFT_BY_REG: bool,
+    >(
+        &mut self,
+        insn: u32,
+    ) -> CpuAction {
         let mut result = CpuAction::AdvancePC(NonSeq);
 
-        let load = insn.load_flag();
-        let pre_index = insn.pre_index_flag();
-        let writeback = insn.write_back_flag();
         let base_reg = insn.bit_range(16..20) as usize;
         let dest_reg = insn.bit_range(12..16) as usize;
         let mut addr = self.get_reg(base_reg);
         if base_reg == REG_PC {
             addr = self.pc_arm() + 8; // prefetching
         }
-        let mut carry = self.cpsr.C();
-        let offset = self.get_barrel_shifted_value(&insn.ldr_str_offset(), &mut carry); // TODO: wrong to use in here
-        drop(carry);
+        let mut offset = insn.bit_range(0..12);
+        if SHIFT {
+            let mut carry = self.cpsr.C();
+            let rm = offset & 0xf;
+            offset =
+                self.register_shift_const::<BS_OP, SHIFT_BY_REG>(offset, rm as usize, &mut carry);
+        }
+        let offset = if ADD {
+            offset as u32
+        } else {
+            (-(offset as i32)) as u32
+        };
         let effective_addr = (addr as i32).wrapping_add(offset as i32) as Addr;
 
         // TODO - confirm this
         let old_mode = self.cpsr.mode();
-        if !pre_index && writeback {
+        if !PRE_INDEX && WRITEBACK {
             self.change_mode(old_mode, CpuMode::User);
         }
 
-        addr = if insn.pre_index_flag() {
-            effective_addr
-        } else {
-            addr
-        };
+        addr = if PRE_INDEX { effective_addr } else { addr };
 
-        if load {
-            let data = if insn.transfer_size() == 1 {
+        if LOAD {
+            let data = if BYTE {
                 self.load_8(addr, NonSeq) as u32
             } else {
                 self.ldr_word(addr, NonSeq)
@@ -346,15 +358,15 @@ impl<I: MemoryInterface> Core<I> {
             };
         }
 
-        if !load || base_reg != dest_reg {
-            if !pre_index {
+        if !LOAD || base_reg != dest_reg {
+            if !PRE_INDEX {
                 self.set_reg(base_reg, effective_addr);
-            } else if insn.write_back_flag() {
+            } else if WRITEBACK {
                 self.set_reg(base_reg, effective_addr);
             }
         }
 
-        if !pre_index && insn.write_back_flag() {
+        if !PRE_INDEX && WRITEBACK {
             self.change_mode(self.cpsr.mode(), old_mode);
         }