| Set instructions | |||||||||||||
| Notice that the branch instructions include: | |||||||||||||
| equality, inequality | |||||||||||||
| relational operations compared to zero | |||||||||||||
| What about general comparison? | |||||||||||||
| Example: $rs < $rt | |||||||||||||
| Need more instructions to compare 2 values directly | |||||||||||||
| Instruction | Semantics | Comparison | |||||||||||
| slt $rd, $rs, $rt # R[d] = R[s] < R[t] ? 1 : 0 | 2C | ||||||||||||
| sltu $rd, $rs, $rt # R[d] = R[s] < R[t] ? 1 : 0 | UB | ||||||||||||
| slti $rt, $rs, immed # R[d] = R[s] < immed ? 1 : 0 | 2C | ||||||||||||
| sltiu $rt, $rs, immed # R[d] = R[s] < immed ? 1 : 0 | UB | ||||||||||||
| Compare 2 registers or register and a constant. | |||||||||||||
| If condition is true, result is set to 1, else 0 (note conditional operator). | |||||||||||||
| Immediate value must be extended with sign bit (2C) or zero (unsigned). | |||||||||||||
| Note that this only sets a value; a separate instruction is needed to do a branch. | |||||||||||||
| What about > operation? | |||||||||||||