fix: Fix LUI, AUIPC and JAL

pattonkan · Feb 10, 2024 · c708837 · c708837
1 parent ac3f7c1
commit c708837
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Showing 4 changed files with 16 additions and 8 deletions.
diff --git a/src/cpu.rs b/src/cpu.rs
@@ -126,7 +126,11 @@ pub fn exec_jal(cpu: &mut CPU, instr: u32) {
     cpu.xregs.regs[rd(instr) as usize] = cpu.pc + 4;
     cpu.pc = (cpu.pc as i64 + imm) as u64;
 }
-pub fn exec_jalr(cpu: &mut CPU, instr: u32) {}
+pub fn exec_jalr(cpu: &mut CPU, instr: u32) {
+    let imm = (imm_J(instr) as i32) as i64;
+    cpu.xregs.regs[rd(instr) as usize] = cpu.pc + 4;
+    cpu.pc = (cpu.pc as i64 + imm) as u64;
+}
 pub fn exec_beq(cpu: &mut CPU, instr: u32) {}
 pub fn exec_bne(cpu: &mut CPU, instr: u32) {}
 pub fn exec_blt(cpu: &mut CPU, instr: u32) {}

diff --git a/src/opcode.rs b/src/opcode.rs
@@ -128,7 +128,7 @@ pub fn imm_I(instr: u32) -> i32 {
 
 pub fn imm_U(instr: u32) -> u64 {
     // imm[31:12] = inst[31:12]
-    return (instr & 0xfffff800) as u64;
+    return (instr & 0xfffff000) as u64;
 }
 
 pub fn imm_J(instr: u32) -> u64 {

diff --git a/tests/cpu_test.rs b/tests/cpu_test.rs
@@ -10,27 +10,27 @@ mod tests {
         let mut cpu_test = cpu::CPU::new();
 
         // lui x5, 4
-        let instr: u32 = helper::set_u_type_instruction(4, 5, LUI as u8);
+        let instr: u32 = helper::set_u_type_instruction(4 << 12, 5, LUI as u8);
         cpu::exec_lui(&mut cpu_test, instr);
         assert_eq!(cpu_test.xregs.regs[5], 4 << 12);
 
         // lui x5, -4
-        let instr: u32 = helper::set_u_type_instruction(-4, 5, LUI as u8);
+        let instr: u32 = helper::set_u_type_instruction(-(4 << 12), 5, LUI as u8);
         cpu::exec_lui(&mut cpu_test, instr);
-        assert_eq!(cpu_test.xregs.regs[5], (-4 << 12) as u64);
+        assert_eq!(cpu_test.xregs.regs[5], -(4 << 12) as u64);
     }
     #[test]
     fn test_exec_auipc() {
         let mut cpu_test = cpu::CPU::new();
 
         let ori_pc = cpu_test.pc;
         // auipc x5, 4
-        let instr: u32 = helper::set_u_type_instruction(4, 5, AUIPC as u8);
+        let instr: u32 = helper::set_u_type_instruction(4 << 12, 5, AUIPC as u8);
         cpu::exec_auipc(&mut cpu_test, instr);
         assert_eq!(cpu_test.xregs.regs[5], ori_pc + (4 << 12));
 
         // auipc x5, -4
-        let instr: u32 = helper::set_u_type_instruction(-4, 5, AUIPC as u8);
+        let instr: u32 = helper::set_u_type_instruction(-(4 << 12), 5, AUIPC as u8);
         cpu::exec_auipc(&mut cpu_test, instr);
         assert_eq!(cpu_test.xregs.regs[5], (ori_pc as i64 + (-4 << 12)) as u64);
     }
@@ -40,7 +40,7 @@ mod tests {
 
         let ori_pc = cpu_test.pc;
         // jal x5, 12
-        let instr: u32 = helper::set_u_type_instruction(12, 5, JAL as u8);
+        let instr: u32 = helper::set_j_type_instruction(12, 5, JAL as u8);
         cpu::exec_jal(&mut cpu_test, instr);
         assert_eq!(cpu_test.xregs.regs[5], ori_pc + 4);
         assert_eq!(cpu_test.pc, ori_pc + 12);

diff --git a/tests/helper.rs b/tests/helper.rs
@@ -13,6 +13,10 @@ pub fn set_i_type_instruction(imm: i16, rs1: u8, funct3: u8, rd: u8) -> u32 {
 }
 
 pub fn set_u_type_instruction(imm: i32, rd: u8, opcode: u8) -> u32 {
+    return (imm as u32 & 0xfffff000) as u32 | ((rd as u32 & 0x1f) << 7) | ((opcode as u32) & 0x7f);
+}
+
+pub fn set_j_type_instruction(imm: i32, rd: u8, opcode: u8) -> u32 {
     // |31-12|11-7|6-0|
     // imm[20|10:1|11|19:12] = instr[31|30:21|20|19:12]
     let instr_imm = (((imm as i64) << 11) & 0x80000000)