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authorEmilio G. Cota <cota@braap.org>2017-04-26 23:29:18 -0400
committerRichard Henderson <rth@twiddle.net>2017-06-05 09:25:42 -0700
commit5cb4ef80f65252dd85b86fa7f3c985015423d670 (patch)
treeb1c76f8692d74f98900fb1e0cd8c81c124a325e7 /tcg/i386
parentcedbcb01529cb6cf9a2289cdbebbc63f6149fc18 (diff)
downloadqemu-5cb4ef80f65252dd85b86fa7f3c985015423d670.tar.gz
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>
Diffstat (limited to 'tcg/i386')
-rw-r--r--tcg/i386/tcg-target.h2
-rw-r--r--tcg/i386/tcg-target.inc.c24
2 files changed, 23 insertions, 3 deletions
diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h
index 59d983525c..73a15f7e80 100644
--- a/tcg/i386/tcg-target.h
+++ b/tcg/i386/tcg-target.h
@@ -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
diff --git a/tcg/i386/tcg-target.inc.c b/tcg/i386/tcg-target.inc.c
index 5918008296..01e3b4e95c 100644
--- a/tcg/i386/tcg-target.inc.c
+++ b/tcg/i386/tcg-target.inc.c
@@ -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;