target/arm: Rearrange decode in disas_uncond_b_reg

This will enable PAuth decode in a subsequent patch.

Backports commit f7cf3bfc1b65a8c550b8439374c0060f7311ad50 from qemu
This commit is contained in:
Richard Henderson 2019-01-22 15:50:43 -05:00 committed by Lioncash
parent 4329ded5e2
commit 0c09366d68
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GPG key ID: 4E3C3CC1031BA9C7

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@ -2070,25 +2070,49 @@ static void disas_uncond_b_reg(DisasContext *s, uint32_t insn)
rn = extract32(insn, 5, 5); rn = extract32(insn, 5, 5);
op4 = extract32(insn, 0, 5); op4 = extract32(insn, 0, 5);
if (op4 != 0x0 || op3 != 0x0 || op2 != 0x1f) { if (op2 != 0x1f) {
unallocated_encoding(s); goto do_unallocated;
return;
} }
switch (opc) { switch (opc) {
case 0: /* BR */ case 0: /* BR */
case 1: /* BLR */ case 1: /* BLR */
case 2: /* RET */ case 2: /* RET */
gen_a64_set_pc(s, cpu_reg(s, rn)); switch (op3) {
case 0:
if (op4 != 0) {
goto do_unallocated;
}
dst = cpu_reg(s, rn);
break;
default:
goto do_unallocated;
}
gen_a64_set_pc(s, dst);
/* BLR also needs to load return address */ /* BLR also needs to load return address */
if (opc == 1) { if (opc == 1) {
tcg_gen_movi_i64(tcg_ctx, cpu_reg(s, 30), s->pc); tcg_gen_movi_i64(tcg_ctx, cpu_reg(s, 30), s->pc);
} }
break; break;
case 4: /* ERET */ case 4: /* ERET */
if (s->current_el == 0) { if (s->current_el == 0) {
unallocated_encoding(s); goto do_unallocated;
return; }
switch (op3) {
case 0:
if (op4 != 0) {
goto do_unallocated;
}
dst = tcg_temp_new_i64(tcg_ctx);
tcg_gen_ld_i64(tcg_ctx, dst, tcg_ctx->cpu_env,
offsetof(CPUARMState, elr_el[s->current_el]));
break;
default:
goto do_unallocated;
} }
dst = tcg_temp_new_i64(tcg_ctx); dst = tcg_temp_new_i64(tcg_ctx);
tcg_gen_ld_i64(tcg_ctx, dst, tcg_ctx->cpu_env, tcg_gen_ld_i64(tcg_ctx, dst, tcg_ctx->cpu_env,
@ -2098,14 +2122,17 @@ static void disas_uncond_b_reg(DisasContext *s, uint32_t insn)
/* Must exit loop to check un-masked IRQs */ /* Must exit loop to check un-masked IRQs */
s->base.is_jmp = DISAS_EXIT; s->base.is_jmp = DISAS_EXIT;
return; return;
case 5: /* DRPS */ case 5: /* DRPS */
if (rn != 0x1f) { if (op3 != 0 || op4 != 0 || rn != 0x1f) {
unallocated_encoding(s); goto do_unallocated;
} else { } else {
unsupported_encoding(s, insn); unsupported_encoding(s, insn);
} }
return; return;
default: default:
do_unallocated:
unallocated_encoding(s); unallocated_encoding(s);
return; return;
} }