| %def binopLit8(extract="asr r1, r3, #8", result="r0", chkzero="0", instr=""): | |
| /* | |
| * Generic 32-bit "lit8" binary operation. Provide an "instr" line | |
| * that specifies an instruction that performs "result = r0 op r1". | |
| * This could be an ARM instruction or a function call. (If the result | |
| * comes back in a register other than r0, you can override "result".) | |
| * | |
| * You can override "extract" if the extraction of the literal value | |
| * from r3 to r1 is not the default "asr r1, r3, #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 (r1). 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 r3, 1 @ r3<- ssssCCBB (sign-extended for CC) | |
| mov r9, rINST, lsr #8 @ r9<- AA | |
| and r2, r3, #255 @ r2<- BB | |
| GET_VREG r0, r2 @ r0<- vBB | |
| $extract @ optional; typically r1<- ssssssCC (sign extended) | |
| .if $chkzero | |
| @cmp r1, #0 @ is second operand zero? | |
| beq common_errDivideByZero | |
| .endif | |
| FETCH_ADVANCE_INST 2 @ advance rPC, load rINST | |
| $instr @ $result<- op, r0-r3 changed | |
| GET_INST_OPCODE ip @ extract opcode from rINST | |
| SET_VREG $result, r9 @ vAA<- $result | |
| GOTO_OPCODE ip @ jump to next instruction | |
| /* 10-12 instructions */ |