On 11/24/20 5:45 AM, Philippe Mathieu-Daudé wrote:
> Release 6 recoded the 'Load Linked Word' using SPECIAL3 opcode,
> this opcode (0b110000) is now reserved.
>
> Ref: A.2 Instruction Bit Encoding Tables:
>
> "6Rm instructions signal a Reserved Instruction exception
> when executed by a Release 6 implementation."
>
> The check was added in commit 4368b29a26e ("target-mips: move
> LL and SC instructions") but got lost during latter refactor
> in commit d9224450208 ("target-mips: Tighten ISA level checks").
I think git blame is confused here -- d9224450208 isn't the one that broke
things. The patch has:
+ case OPC_LL: /* Load and stores */
+ check_insn(ctx, ISA_MIPS2);
+ /* Fallthrough */
+ case OPC_LWL:
case OPC_LWR:
- case OPC_LL:
check_insn_opc_removed(ctx, ISA_MIPS32R6);
+ /* Fallthrough */
Whereever it happened, it's broken now, so
Reviewed-by: Richard Henderson <[email protected]>
r~
