Copy
29function applyOp(
30    bytes memory,
31    State memory state_,
32    uint256 opcode_,
33    uint256 operand_
34) internal pure {
35    require(opcode_ < OPS_LENGTH, "MAX_OPCODE");
36    uint256 top_;
37    unchecked {
38        top_ = state_.stackIndex - 1;
39        state_.stackIndex -= operand_;
40    }
41    uint256 baseIndex_ = state_.stackIndex;
42    uint256 cursor_ = baseIndex_;
43    uint256 accumulator_ = state_.stack[cursor_];
44
45    // Addition.
46    if (opcode_ == ADD) {
47        while (cursor_ < top_) {
48            unchecked {
49                cursor_++;
50            }
51            accumulator_ += state_.stack[cursor_];
52        }
53    }
54    // Subtraction.
55    else if (opcode_ == SUB) {
56        while (cursor_ < top_) {
57            unchecked {
58                cursor_++;
59            }
60            accumulator_ -= state_.stack[cursor_];
61        }
62    }
63    // Multiplication.
64    // Slither false positive here complaining about dividing before
65    // multiplying but both are mututally exclusive according to `opcode_`.
66    else if (opcode_ == MUL) {
67        while (cursor_ < top_) {
68            unchecked {
69                cursor_++;
70            }
71            accumulator_ *= state_.stack[cursor_];
72        }
73    }
74    // Division.
75    else if (opcode_ == DIV) {
76        while (cursor_ < top_) {
77            unchecked {
78                cursor_++;
79            }
80            accumulator_ /= state_.stack[cursor_];
81        }
82    }
83    // Modulo.
84    else if (opcode_ == MOD) {
85        while (cursor_ < top_) {
86            unchecked {
87                cursor_++;
88            }
89            accumulator_ %= state_.stack[cursor_];
90        }
91    }
92    // Exponentiation.
93    else if (opcode_ == EXP) {
94        while (cursor_ < top_) {
95            unchecked {
96                cursor_++;
97            }
98            accumulator_**state_.stack[cursor_];
99        }
100    }
101    // Minimum.
102    else if (opcode_ == MIN) {
103        uint256 item_;
104        while (cursor_ < top_) {
105            unchecked {
106                cursor_++;
107            }
108            item_ = state_.stack[cursor_];
109            if (item_ < accumulator_) {
110                accumulator_ = item_;
111            }
112        }
113    }
114    // Maximum.
115    else if (opcode_ == MAX) {
116        uint256 item_;
117        while (cursor_ < top_) {
118            unchecked {
119                cursor_++;
120            }
121            item_ = state_.stack[cursor_];
122            if (item_ > accumulator_) {
123                accumulator_ = item_;
124            }
125        }
126    }
127
128    unchecked {
129        state_.stack[baseIndex_] = accumulator_;
130        state_.stackIndex++;
131    }
132}