1 files changed, 100 insertions, 0 deletions
diff --git a/rv64cpu/tb/unit/tb_branch.cc b/rv64cpu/tb/unit/tb_branch.cc
new file mode 100644
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--- /dev/null
+++ b/rv64cpu/tb/unit/tb_branch.cc
@@ -0,0 +1,100 @@
+//     Richard CPU
+//     Copyright (C) 2026  Richard Qin
+//     This program is free software: you can redistribute it and/or modify
+//     it under the terms of the GNU General Public License as published by
+//     the Free Software Foundation, either version 3 of the License, or
+//     (at your option) any later version.
+
+//     This program is distributed in the hope that it will be useful,
+//     but WITHOUT ANY WARRANTY; without even the implied warranty of
+//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//     GNU General Public License for more details.
+
+//     You should have received a copy of the GNU General Public License
+//     along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+// File path: tb/unit/tb_branch.cc
+// Description: Branch Unit test
+
+#include <iostream>
+#include <iomanip>
+#include <cstdint>
+#include <cassert>
+#include <verilated.h>
+#include "Vbranch_unit.h"
+
+// Enums must match rv64_pkg::branch_op_t
+enum BranchOp {
+    BRANCH_EQ  = 0b000,
+    BRANCH_NE  = 0b001,
+    BRANCH_LT  = 0b100,
+    BRANCH_GE  = 0b101,
+    BRANCH_LTU = 0b110,
+    BRANCH_GEU = 0b111
+};
+
+void test_branch(Vbranch_unit* dut, uint8_t is_branch, uint8_t op, uint64_t a, uint64_t b, uint8_t expected, const char* name) {
+    dut->is_branch = is_branch;
+    dut->branch_op = op;
+    dut->operand_a = a;
+    dut->operand_b = b;
+    dut->eval();
+
+    if (dut->branch_taken == expected) {
+        std::cout << "\033[32m[PASS] " << name << " | Expected: " << (int)expected << " Got: " << (int)dut->branch_taken << "\033[0m" << std::dec << std::endl;
+    } else {
+        std::cout << "\033[31m[FAIL] " << name << " | Expected: " << (int)expected << " Got: " << (int)dut->branch_taken << "\033[0m" << std::endl;
+        assert(false);
+    }
+}
+
+int main(int argc, char** argv) {
+    Verilated::commandArgs(argc, argv);
+    Vbranch_unit* dut = new Vbranch_unit;
+
+    std::cout << "----------------------------------" << std::endl;
+    std::cout << "        Branch Unit Test" << std::endl;
+    std::cout << "----------------------------------" << std::endl;
+
+    // --- Not a branch ---
+    test_branch(dut, 0, BRANCH_EQ, 10, 10, 0, "Not_A_Branch");
+
+    // --- BEQ / BNE ---
+    test_branch(dut, 1, BRANCH_EQ, 10, 10, 1, "BEQ_Equal");
+    test_branch(dut, 1, BRANCH_EQ, 10, 20, 0, "BEQ_Not_Equal");
+    test_branch(dut, 1, BRANCH_NE, 10, 20, 1, "BNE_Not_Equal");
+    test_branch(dut, 1, BRANCH_NE, 10, 10, 0, "BNE_Equal");
+
+    uint64_t minus_one = (uint64_t)-1; // 0xFFFFFFFFFFFFFFFF
+    uint64_t one = 1;
+
+    // --- BLT / BGE (Signed) ---
+    // -1 is less than 1 (Signed)
+    test_branch(dut, 1, BRANCH_LT, minus_one, one, 1, "BLT_Signed_Negative_vs_Positive");
+    test_branch(dut, 1, BRANCH_GE, minus_one, one, 0, "BGE_Signed_Negative_vs_Positive");
+    
+    // 1 is greater than -1 (Signed)
+    test_branch(dut, 1, BRANCH_LT, one, minus_one, 0, "BLT_Signed_Positive_vs_Negative");
+    test_branch(dut, 1, BRANCH_GE, one, minus_one, 1, "BGE_Signed_Positive_vs_Negative");
+
+    // Equal signed
+    test_branch(dut, 1, BRANCH_LT, minus_one, minus_one, 0, "BLT_Signed_Equal");
+    test_branch(dut, 1, BRANCH_GE, minus_one, minus_one, 1, "BGE_Signed_Equal");
+
+    // --- BLTU / BGEU (Unsigned) ---
+    // 0xFFFFFFFFFFFFFFFF is NOT less than 1 (Unsigned)
+    test_branch(dut, 1, BRANCH_LTU, minus_one, one, 0, "BLTU_Unsigned_Max_vs_1");
+    // 0xFFFFFFFFFFFFFFFF is greater than or equal to 1 (Unsigned)
+    test_branch(dut, 1, BRANCH_GEU, minus_one, one, 1, "BGEU_Unsigned_Max_vs_1");
+
+    // Equal unsigned
+    test_branch(dut, 1, BRANCH_LTU, minus_one, minus_one, 0, "BLTU_Unsigned_Equal");
+    test_branch(dut, 1, BRANCH_GEU, minus_one, minus_one, 1, "BGEU_Unsigned_Equal");
+
+    std::cout << "----------------------------------" << std::endl;
+    std::cout << "\033[32mAll tests passed!\033[0m" << std::endl;
+    std::cout << "----------------------------------" << std::endl;
+
+    delete dut;
+    return 0;
+}