qwen3-coder:30b | RAG on

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. Both operands are positive and result is negative (A >= 0, B < 0, result < 0)
    // 2. Both operands are negative and result is positive (A < 0, B >= 0, result >= 0)
    assign overflow = (A[63] == 0 && B[63] == 1 && result[63] == 1) ||
                      (A[63] == 1 && B[63] == 0 && result[63] == 0);

endmodule

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (A and B same sign, result opposite)
    // 2. This can be detected by checking if the carry into MSB differs from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag: set when signs of A and B are same, but sign of result is different
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;
    
    // Compute two's complement of B
    assign B_comp = ~B;
    
    // Add A and two's complement of B (A - B = A + (-B))
    // Use 65-bit addition to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;
    
    // Extract result (64-bit)
    assign result = sum[63:0];
    
    // Overflow detection for signed 64-bit arithmetic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (positive + negative = negative or negative + positive = positive)
    // 2. This can be detected by checking if the carry into MSB differs from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag: set when there's a carry into MSB but no carry out, or vice versa
    assign overflow = carry_in ^ carry_out;
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;
    
    // Compute two's complement of B
    assign B_comp = ~B;
    
    // Add A and two's complement of B (A - B = A + (-B))
    // Use 65-bit addition to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;
    
    // Result is the lower 64 bits of sum
    assign result = sum[63:0];
    
    // Overflow detection for signed 64-bit arithmetic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (positive + negative = negative or negative + positive = positive)
    // 2. This can be detected by checking if the carry into MSB is different from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag: set when there's a carry into MSB but not out, or vice versa
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (A and B same sign, result opposite)
    // 2. This can be detected by checking if the carry into MSB differs from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag: set when signs of A and B are same, but sign of result is different
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (A and B same sign, result opposite)
    // 2. This can be detected by checking if the carry into MSB differs from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;
    
    // Compute two's complement of B
    assign B_comp = ~B;
    
    // Perform addition A + (-B) using two's complement
    // Add 1 to B_comp to get two's complement
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1;
    
    // Extract result (64-bit)
    assign result = sum[63:0];
    
    // Overflow detection for signed arithmetic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (A and B same sign, result different)
    // 2. This can be detected by checking if the carry into MSB differs from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag: set when there's a carry into MSB but not out, or vice versa
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. A is positive and B is negative, and result is negative (positive overflow)
    // 2. A is negative and B is positive, and result is positive (negative overflow)
    assign overflow = (A[63] == 1'b0 && B[63] == 1'b1 && result[63] == 1'b1) ||
                      (A[63] == 1'b1 && B[63] == 1'b0 && result[63] == 1'b0);

endmodule

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (A and B same sign, result opposite)
    // 2. This can be detected by checking if the carry into MSB differs from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;
    
    // Compute two's complement of B
    assign B_comp = ~B;
    
    // Add A and two's complement of B (A - B = A + (-B))
    // Use 65-bit addition to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;
    
    // Extract result (64-bit)
    assign result = sum[63:0];
    
    // Overflow detection for signed 64-bit arithmetic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (positive + negative = negative or negative + positive = positive)
    // 2. This can be detected by checking if the carry into MSB is different from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag: set when signs of A and B are same, but sign of result is different
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (A and B same sign, result opposite)
    // 2. This can be detected by checking if the carry into MSB differs from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag: set when signs of A and B are same, but sign of result is different
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. Both operands are positive and result is negative (A >= 0, B < 0, result < 0)
    // 2. Both operands are negative and result is positive (A < 0, B >= 0, result >= 0)
    assign overflow = (A[63] == 0 && B[63] == 1 && result[63] == 1) ||
                      (A[63] == 1 && B[63] == 0 && result[63] == 0);

endmodule

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;
    
    // Compute two's complement of B
    assign B_comp = ~B;
    
    // Add A and two's complement of B (A - B = A + (-B))
    // Use 65-bit addition to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;
    
    // Extract result (64-bit)
    assign result = sum[63:0];
    
    // Overflow detection for signed 64-bit arithmetic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (positive + negative = negative or negative + positive = positive)
    // 2. This can be detected by checking if the carry into MSB is different from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag: set when signs of A and B are same, but sign of result is different
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (A and B same sign, result opposite)
    // 2. This can be detected by checking if the carry into MSB differs from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag: set when signs of A and B are same, but sign of result is different
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. Both operands are positive and result is negative (A >= 0, B < 0, result < 0)
    // 2. Both operands are negative and result is positive (A < 0, B >= 0, result >= 0)
    assign overflow = (A[63] == 0 && B[63] == 1 && result[63] == 1) ||
                      (A[63] == 1 && B[63] == 0 && result[63] == 0);

endmodule

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;
    
    // Compute two's complement of B
    assign B_comp = ~B;
    
    // Perform addition A + (-B) using two's complement
    // Add 1 to B_comp to get two's complement
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1;
    
    // Extract result (64-bit)
    assign result = sum[63:0];
    
    // Overflow detection for signed arithmetic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (A and B same sign, result different)
    // 2. This can be detected by checking if the carry into MSB differs from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag: set when there's a carry into MSB but not out, or vice versa
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. Both operands are positive and result is negative (A >= 0, B < 0, result < 0)
    // 2. Both operands are negative and result is positive (A < 0, B >= 0, result >= 0)
    assign overflow = (A[63] == 0 && B[63] == 1 && result[63] == 1) ||
                      (A[63] == 1 && B[63] == 0 && result[63] == 0);

endmodule

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. A is positive and B is negative, and result is negative (positive - negative = negative)
    // 2. A is negative and B is positive, and result is positive (negative - positive = positive)
    assign overflow = (A[63] == 1'b0 && B[63] == 1'b1 && result[63] == 1'b1) ||
                      (A[63] == 1'b1 && B[63] == 1'b0 && result[63] == 1'b0);

endmodule

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;
    
    // Compute two's complement of B
    assign B_comp = ~B;
    
    // Add A and two's complement of B (A - B = A + (-B))
    // Use 65-bit addition to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;
    
    // Extract result (64-bit)
    assign result = sum[63:0];
    
    // Overflow detection for signed 64-bit arithmetic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (positive + negative = negative or negative + positive = positive)
    // 2. This can be detected by checking if the carry into MSB is different from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag: set when signs of A and B are same, but sign of result is different
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (A and B same sign, result opposite)
    // 2. This can be detected by checking if the carry into MSB differs from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (A and B same sign, result opposite)
    // 2. This can be detected by checking if the carry into MSB differs from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;
    
    // Compute two's complement of B
    assign B_comp = ~B;
    
    // Perform addition A + (-B) using two's complement
    // Add 1 to B_comp to get two's complement
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1;
    
    // Extract result (64-bit)
    assign result = sum[63:0];
    
    // Overflow detection for signed arithmetic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (A and B same sign, result different)
    // 2. This can be detected by checking if the carry into MSB differs from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag: set when there's a carry into MSB but not out, or vice versa
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (A and B same sign, result opposite)
    // 2. This can be detected by checking if the carry into MSB differs from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. A is positive and B is negative, and result is negative (positive - negative = negative)
    // 2. A is negative and B is positive, and result is positive (negative - positive = positive)
    assign overflow = (A[63] == 1'b0 && B[63] == 1'b1 && result[63] == 1'b1) ||
                      (A[63] == 1'b1 && B[63] == 1'b0 && result[63] == 1'b0);

endmodule

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;
    
    // Compute two's complement of B
    assign B_comp = ~B;
    
    // Add A and two's complement of B (A - B)
    // Using 65-bit addition to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;
    
    // Result is the lower 64 bits of sum
    assign result = sum[63:0];
    
    // Overflow detection
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (A and B both positive, result negative)
    // 2. Both operands have same sign, but result has different sign (A and B both negative, result positive)
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);

endmodule

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (A and B same sign, result opposite)
    // 2. This can be detected by checking if the carry into MSB differs from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow flag: set when signs of A and B are same, but sign of result is different
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. Both operands are positive and result is negative (A >= 0, B < 0, result < 0)
    // 2. Both operands are negative and result is positive (A < 0, B >= 0, result >= 0)
    assign overflow = (A[63] == 0) && (B[63] == 1) && (result[63] == 1) ||
                      (A[63] == 1) && (B[63] == 0) && (result[63] == 0);

endmodule

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;
    
    // Compute two's complement of B
    assign B_comp = ~B;
    
    // Add A and two's complement of B (A - B)
    // Using 65-bit addition to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;
    
    // Result is the lower 64 bits of sum
    assign result = sum[63:0];
    
    // Overflow detection
    // Overflow occurs when:
    // 1. Both operands have same sign, but result has different sign (A and B both positive, result negative)
    // 2. Both operands have same sign, but result has different sign (A and B both negative, result positive)
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);

endmodule

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. Both operands are positive and result is negative (A >= 0, B < 0, result < 0)
    // 2. Both operands are negative and result is positive (A < 0, B >= 0, result >= 0)
    assign overflow = (A[63] == 0 && B[63] == 1 && result[63] == 1) ||
                      (A[63] == 1 && B[63] == 0 && result[63] == 0);

endmodule

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;

    // Compute two's complement of B
    assign B_comp = ~B;

    // Perform addition A + (-B) using 65-bit adder to detect overflow
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1'b1;

    // Extract 64-bit result
    assign result = sum[63:0];

    // Overflow detection logic
    // Overflow occurs when:
    // 1. A is positive and B is negative, and result is negative (positive - negative = negative)
    // 2. A is negative and B is positive, and result is positive (negative - positive = positive)
    assign overflow = (A[63] == 1'b0 && B[63] == 1'b1 && result[63] == 1'b1) ||
                      (A[63] == 1'b1 && B[63] == 1'b0 && result[63] == 1'b0);

endmodule

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}

module sub_64bit(
    input  [63:0] A,
    input  [63:0] B,
    output [63:0] result,
    output        overflow
);

    wire [63:0] B_comp;
    wire [64:0] sum;
    wire        carry_in;
    wire        carry_out;
    
    // Compute two's complement of B
    assign B_comp = ~B;
    
    // Perform addition A + (-B) using two's complement
    // Add 1 to the two's complement to get the actual negative value
    assign sum = {1'b0, A} + {1'b0, B_comp} + 1;
    
    // Extract 64-bit result
    assign result = sum[63:0];
    
    // Overflow detection for signed 64-bit arithmetic
    // Overflow occurs when:
    // 1. Both operands have the same sign, but result has different sign (positive + negative = negative or negative + positive = positive)
    // 2. This can be detected by checking if the carry into MSB is different from carry out of MSB
    
    assign carry_in = sum[64];
    assign carry_out = sum[64];
    
    // Overflow condition: when signs of A and B are same but sign of result is different
    assign overflow = (A[63] == B[63]) && (A[63] != result[63]);
...

[stdout]
=========== Your Design Passed ===========
/workspace/banchmarks/rtllm/13_rtllm_arithmetic/task_19/tb.v:48: $finish called at 1000000 (1ps)

[error]
None

{
  "llm_ok": true,
  "extract_ok": true,
  "syntax_ok": true,
  "functional_ok": true,
  "openlane_ok": true,
  "syntax_required": true,
  "functional_required": true,
  "openlane_required": true,
  "final_success": true,
  "success": true
}