tcg/i386: implement goto_ptr

Suggested-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1493263764-18657-6-git-send-email-cota@braap.org>
[rth: Reuse goto_ptr epilogue for exit_tb 0.]
Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Emilio G. Cota 2017-04-26 23:29:18 -04:00 committed by Richard Henderson
parent cedbcb0152
commit 5cb4ef80f6
2 changed files with 23 additions and 3 deletions

View File

@ -107,7 +107,7 @@ extern bool have_popcnt;
#define TCG_TARGET_HAS_muls2_i32 1
#define TCG_TARGET_HAS_muluh_i32 0
#define TCG_TARGET_HAS_mulsh_i32 0
#define TCG_TARGET_HAS_goto_ptr 0
#define TCG_TARGET_HAS_goto_ptr 1
#if TCG_TARGET_REG_BITS == 64
#define TCG_TARGET_HAS_extrl_i64_i32 0

View File

@ -1882,8 +1882,13 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
switch (opc) {
case INDEX_op_exit_tb:
tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_EAX, a0);
tcg_out_jmp(s, tb_ret_addr);
/* Reuse the zeroing that exists for goto_ptr. */
if (a0 == 0) {
tcg_out_jmp(s, s->code_gen_epilogue);
} else {
tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_EAX, a0);
tcg_out_jmp(s, tb_ret_addr);
}
break;
case INDEX_op_goto_tb:
if (s->tb_jmp_insn_offset) {
@ -1906,6 +1911,10 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
}
s->tb_jmp_reset_offset[a0] = tcg_current_code_size(s);
break;
case INDEX_op_goto_ptr:
/* jmp to the given host address (could be epilogue) */
tcg_out_modrm(s, OPC_GRP5, EXT5_JMPN_Ev, a0);
break;
case INDEX_op_br:
tcg_out_jxx(s, JCC_JMP, arg_label(a0), 0);
break;
@ -2277,6 +2286,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc,
static const TCGTargetOpDef *tcg_target_op_def(TCGOpcode op)
{
static const TCGTargetOpDef r = { .args_ct_str = { "r" } };
static const TCGTargetOpDef ri_r = { .args_ct_str = { "ri", "r" } };
static const TCGTargetOpDef re_r = { .args_ct_str = { "re", "r" } };
static const TCGTargetOpDef qi_r = { .args_ct_str = { "qi", "r" } };
@ -2299,6 +2309,9 @@ static const TCGTargetOpDef *tcg_target_op_def(TCGOpcode op)
= { .args_ct_str = { "L", "L", "L", "L" } };
switch (op) {
case INDEX_op_goto_ptr:
return &r;
case INDEX_op_ld8u_i32:
case INDEX_op_ld8u_i64:
case INDEX_op_ld8s_i32:
@ -2567,6 +2580,13 @@ static void tcg_target_qemu_prologue(TCGContext *s)
tcg_out_modrm(s, OPC_GRP5, EXT5_JMPN_Ev, tcg_target_call_iarg_regs[1]);
#endif
/*
* Return path for goto_ptr. Set return value to 0, a-la exit_tb,
* and fall through to the rest of the epilogue.
*/
s->code_gen_epilogue = s->code_ptr;
tcg_out_movi(s, TCG_TYPE_REG, TCG_REG_EAX, 0);
/* TB epilogue */
tb_ret_addr = s->code_ptr;