[Qemu-devel] [PATCH v3 04/10] tcg/i386: implement goto_ptr op

[Emilio G. Cota]

Signed-off-by: Emilio G. Cota <c...@braap.org>
---
 tcg/i386/tcg-target.h     |  2 +-
 tcg/i386/tcg-target.inc.c | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h
index 59d9835..73a15f7 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 5918008..d0bf53a 100644
--- a/tcg/i386/tcg-target.inc.c
+++ b/tcg/i386/tcg-target.inc.c
@@ -1906,6 +1906,10 @@ 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 +2281,7 @@ 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 +2304,9 @@ 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 +2575,13 @@ 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;
 
-- 
2.7.4