| %default {"extract": "asr w1, w3, #8", "preinstr":"", "result":"w0", "chkzero":"0"} | |
| /* | |
| * Generic 32-bit "lit8" binary operation. Provide an "instr" line | |
| * that specifies an instruction that performs "result = w0 op w1". | |
| * This could be an ARM instruction or a function call. (If the result | |
| * comes back in a register other than w0, you can override "result".) | |
| * | |
| * You can override "extract" if the extraction of the literal value | |
| * from w3 to w1 is not the default "asr w1, w3, #8". The extraction | |
| * can be omitted completely if the shift is embedded in "instr". | |
| * | |
| * If "chkzero" is set to 1, we perform a divide-by-zero check on | |
| * vCC (w1). Useful for integer division and modulus. | |
| * | |
| * For: add-int/lit8, rsub-int/lit8, mul-int/lit8, div-int/lit8, | |
| * rem-int/lit8, and-int/lit8, or-int/lit8, xor-int/lit8, | |
| * shl-int/lit8, shr-int/lit8, ushr-int/lit8 | |
| */ | |
| /* binop/lit8 vAA, vBB, #+CC */ | |
| FETCH_S w3, 1 // w3<- ssssCCBB (sign-extended for CC) | |
| lsr w9, wINST, #8 // w9<- AA | |
| and w2, w3, #255 // w2<- BB | |
| GET_VREG w0, w2 // w0<- vBB | |
| $extract // optional; typically w1<- ssssssCC (sign extended) | |
| .if $chkzero | |
| cbz w1, common_errDivideByZero | |
| .endif | |
| FETCH_ADVANCE_INST 2 // advance rPC, load rINST | |
| $preinstr // optional op; may set condition codes | |
| $instr // $result<- op, w0-w3 changed | |
| GET_INST_OPCODE ip // extract opcode from rINST | |
| SET_VREG $result, w9 // vAA<- $result | |
| GOTO_OPCODE ip // jump to next instruction | |
| /* 10-12 instructions */ |