| Alexey Frunze | 00b53b7 | 2016-02-02 20:25:45 -0800 | [diff] [blame] | 1 | %default {"preinstr":"", "result":"a0", "chkzero":"0"} |
| 2 | /* |
| 3 | * Generic 32-bit "/2addr" binary operation. Provide an "instr" line |
| 4 | * that specifies an instruction that performs "result = a0 op a1". |
| 5 | * This could be a MIPS instruction or a function call. (If the result |
| 6 | * comes back in a register other than a0, you can override "result".) |
| 7 | * |
| 8 | * If "chkzero" is set to 1, we perform a divide-by-zero check on |
| 9 | * vB (a1). Useful for integer division and modulus. Note that we |
| 10 | * *don't* check for (INT_MIN / -1) here, because the CPU handles it |
| 11 | * correctly. |
| 12 | * |
| 13 | * For: add-int/2addr, sub-int/2addr, mul-int/2addr, div-int/2addr, |
| 14 | * rem-int/2addr, and-int/2addr, or-int/2addr, xor-int/2addr, |
| 15 | * shl-int/2addr, shr-int/2addr, ushr-int/2addr |
| 16 | */ |
| 17 | /* binop/2addr vA, vB */ |
| 18 | ext a2, rINST, 8, 4 # a2 <- A |
| 19 | ext a3, rINST, 12, 4 # a3 <- B |
| 20 | GET_VREG a0, a2 # a0 <- vA |
| 21 | GET_VREG a1, a3 # a1 <- vB |
| 22 | .if $chkzero |
| 23 | beqz a1, common_errDivideByZero # is second operand zero? |
| 24 | .endif |
| 25 | FETCH_ADVANCE_INST 1 # advance rPC, load rINST |
| 26 | $preinstr # optional op |
| 27 | $instr # $result <- op, a0-a3 changed |
| 28 | GET_INST_OPCODE v0 # extract opcode from rINST |
| 29 | SET_VREG $result, a2 # vA <- $result |
| 30 | GOTO_OPCODE v0 # jump to next instruction |