On 10/14/23 03:01, Paolo Bonzini wrote:
+ [0x28] = X86_OP_ENTRY2(SUB, E,b, G,b),
+ [0x29] = X86_OP_ENTRY2(SUB, E,v, G,v),
+ [0x2A] = X86_OP_ENTRY2(SUB, G,b, E,b),
+ [0x2B] = X86_OP_ENTRY2(SUB, G,v, E,v),
+ [0x2C] = X86_OP_ENTRY2(SUB, 0,b, I,b), /* AL, Ib */
+ [0x2D] = X86_OP_ENTRY2(SUB, 0,v, I,z), /* rAX, Iz */
+ [0x2E] = {},
+ [0x2F] = X86_OP_ENTRY0(DAS, chk(i64)),
+
+ [0x38] = X86_OP_ENTRY2(SUB, E,b, G,b, nowb),
+ [0x39] = X86_OP_ENTRY2(SUB, E,v, G,v, nowb),
+ [0x3A] = X86_OP_ENTRY2(SUB, G,b, E,b, nowb),
+ [0x3B] = X86_OP_ENTRY2(SUB, G,v, E,v, nowb),
+ [0x3C] = X86_OP_ENTRY2(SUB, 0,b, I,b, nowb), /* AL, Ib */
+ [0x3D] = X86_OP_ENTRY2(SUB, 0,v, I,z, nowb), /* rAX, Iz */
+ [0x3E] = {},
+ [0x3F] = X86_OP_ENTRY0(AAS, chk(i64)),
...
+ case X86_SPECIAL_NoWriteback:
+ decode.op[0].unit = X86_OP_SKIP;
+ break;
...
+static void gen_SUB(DisasContext *s, CPUX86State *env, X86DecodedInsn *decode)
+{
+ MemOp ot = decode->op[0].ot;
+
+ if (s->prefix & PREFIX_LOCK) {
+ tcg_gen_neg_tl(s->T0, s->T1);
+ tcg_gen_atomic_fetch_add_tl(s->cc_srcT, s->A0, s->T0,
+ s->mem_index, ot | MO_LE);
+ tcg_gen_sub_tl(s->T0, s->cc_srcT, s->T1);
+ } else {
+ tcg_gen_mov_tl(s->cc_srcT, s->T0);
+ tcg_gen_sub_tl(s->T0, s->T0, s->T1);
+ }
+ prepare_update2_cc(decode, s, CC_OP_SUBB + ot);
+}
Missing a check for CMP vs PREFIX_LOCK.
I'm not sure where the best place to put that.
Whether you use a chk bit or simply hard-code a check for (!lock || !skip).
r~
