target/i386: split legacy decoder into a separate function

Split the bits that have some duplication with disas_insn_new, from
those that should be the main topic of the conversion.  This is the
first step towards removing duplicate decoding of prefixes between
disas_insn and disas_insn_new.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2023-12-22 17:30:06 +01:00
parent 7795b455dd
commit ef309ec2a6

View file

@ -3117,15 +3117,15 @@ static bool disas_insn_x87(DisasContext *s, CPUState *cpu, int b)
return true;
}
static void disas_insn_old(DisasContext *s, CPUState *cpu, int b);
/* convert one instruction. s->base.is_jmp is set if the translation must
be stopped. Return the next pc value */
static bool disas_insn(DisasContext *s, CPUState *cpu)
{
CPUX86State *env = cpu_env(cpu);
int b, prefixes;
int shift;
MemOp ot, aflag, dflag;
int modrm, reg, rm, mod, op, opreg, val;
MemOp aflag, dflag;
bool orig_cc_op_dirty = s->cc_op_dirty;
CCOp orig_cc_op = s->cc_op;
target_ulong orig_pc_save = s->pc_save;
@ -3271,6 +3271,38 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
s->aflag = aflag;
s->dflag = dflag;
switch (b) {
case 0 ... 0xd7:
case 0xe0 ... 0xff:
case 0x10e ... 0x117:
case 0x128 ... 0x12f:
case 0x138 ... 0x19f:
case 0x1a0 ... 0x1a1:
case 0x1a8 ... 0x1a9:
case 0x1af:
case 0x1b2:
case 0x1b4 ... 0x1b7:
case 0x1be ... 0x1bf:
case 0x1c2 ... 0x1c6:
case 0x1c8 ... 0x1ff:
disas_insn_new(s, cpu, b);
break;
default:
disas_insn_old(s, cpu, b);
break;
}
return true;
}
static void disas_insn_old(DisasContext *s, CPUState *cpu, int b)
{
CPUX86State *env = cpu_env(cpu);
int prefixes = s->prefix;
MemOp dflag = s->dflag;
int shift;
MemOp ot;
int modrm, reg, rm, mod, op, opreg, val;
/* now check op code */
switch (b) {
/**************************/
@ -4726,31 +4758,15 @@ static bool disas_insn(DisasContext *s, CPUState *cpu)
set_cc_op(s, CC_OP_POPCNT);
break;
case 0 ... 0xd7:
case 0xe0 ... 0xff:
case 0x10e ... 0x117:
case 0x128 ... 0x12f:
case 0x138 ... 0x19f:
case 0x1a0 ... 0x1a1:
case 0x1a8 ... 0x1a9:
case 0x1af:
case 0x1b2:
case 0x1b4 ... 0x1b7:
case 0x1be ... 0x1bf:
case 0x1c2 ... 0x1c6:
case 0x1c8 ... 0x1ff:
disas_insn_new(s, cpu, b);
break;
default:
goto unknown_op;
}
return true;
return;
illegal_op:
gen_illegal_opcode(s);
return true;
return;
unknown_op:
gen_unknown_opcode(env, s);
return true;
}
void tcg_x86_init(void)