diff mbox

[v2,06/13] tcg: add goto_ptr opcode

Message ID 1493106839-10438-7-git-send-email-cota@braap.org (mailing list archive)
State New, archived
Headers show

Commit Message

Emilio Cota April 25, 2017, 7:53 a.m. UTC 
Signed-off-by: Emilio G. Cota <cota@braap.org>
---
 tcg/README               | 11 +++++++++++
 tcg/aarch64/tcg-target.h |  1 +
 tcg/arm/tcg-target.h     |  1 +
 tcg/i386/tcg-target.h    |  1 +
 tcg/ia64/tcg-target.h    |  1 +
 tcg/mips/tcg-target.h    |  1 +
 tcg/ppc/tcg-target.h     |  1 +
 tcg/s390/tcg-target.h    |  1 +
 tcg/sparc/tcg-target.h   |  1 +
 tcg/tcg-op.c             |  9 +++++++++
 tcg/tcg-op.h             |  9 +++++++++
 tcg/tcg-opc.h            |  1 +
 tcg/tcg.c                |  1 +
 tcg/tci/tcg-target.h     |  1 +
 14 files changed, 40 insertions(+)

Comments

Richard Henderson April 25, 2017, 11:05 a.m. UTC | #1 
On 04/25/2017 09:53 AM, Emilio G. Cota wrote:
> @@ -1138,6 +1138,7 @@ void tcg_dump_ops(TCGContext *s)
>               }
>               switch (c) {
>               case INDEX_op_set_label:
> +            case INDEX_op_goto_tb:
>               case INDEX_op_br:
>               case INDEX_op_brcond_i32:
>               case INDEX_op_brcond_i64:

This is wrong, and causes crashes when dumping.  Nor should goto_ptr be here, 
so I don't know what you were after.


r~
Richard Henderson April 25, 2017, 12:09 p.m. UTC | #2 
On 04/25/2017 09:53 AM, Emilio G. Cota wrote:
> +void tcg_gen_goto_ptr(TCGv_ptr ptr)
> +{
> +    if (TCG_TARGET_HAS_goto_ptr) {
> +        tcg_gen_op1i(INDEX_op_goto_ptr, GET_TCGV_PTR(ptr));
> +    } else {
> +        tcg_gen_exit_tb(0);
> +    }
> +}
> +

I think this function should look more like

void tcg_gen_lookup_and_goto_ptr(TCGv target_addr)
{
     if (TCG_TARGET_HAS_goto_ptr) {
         TCGv_ptr ptr = tcg_temp_new_ptr();
         gen_helper_lookup_tb_ptr(ptr, tcg_ctx.tcg_env, addr);
         tcg_gen_op1i(INDEX_op_goto_ptr, GET_TCGV_PTR(ptr));
         tcg_temp_free_ptr(ptr);
     } else {
         tcg_gen_exit_tb(0);
     }
}

since there's not really any point in all targets being exposed to the 
implementation detail of lookup_tb_ptr.


r~
diff mbox

Patch

diff --git a/tcg/README b/tcg/README
index a9858c2..9cfd422 100644
--- a/tcg/README
+++ b/tcg/README
@@ -477,6 +477,17 @@  current TB was linked to this TB. Otherwise execute the next
 instructions. Only indices 0 and 1 are valid and tcg_gen_goto_tb may be issued
 at most once with each slot index per TB.
 
+* goto_ptr ptr
+
+Jump to a host address given by host pointer 'ptr'.  Typically ptr is obtained
+from the lookup_tb_ptr TCG helper. The return value of this helper depends on
+whether the TB is currently valid: if it is, the corresponding host address
+is returned; if it is not valid, the helper returns the address of the TCG
+epilogue, which restores state to go back to the exec loop.
+
+Implementing goto_ptr is optional for TCG backends. When not implemented,
+calling it is equivalent to calling exit_tb(0).
+
 * qemu_ld_i32/i64 t0, t1, flags, memidx
 * qemu_st_i32/i64 t0, t1, flags, memidx
 
diff --git a/tcg/aarch64/tcg-target.h b/tcg/aarch64/tcg-target.h
index 1a5ea23..b82eac4 100644
--- a/tcg/aarch64/tcg-target.h
+++ b/tcg/aarch64/tcg-target.h
@@ -77,6 +77,7 @@  typedef enum {
 #define TCG_TARGET_HAS_mulsh_i32        0
 #define TCG_TARGET_HAS_extrl_i64_i32    0
 #define TCG_TARGET_HAS_extrh_i64_i32    0
+#define TCG_TARGET_HAS_goto_ptr         0
 
 #define TCG_TARGET_HAS_div_i64          1
 #define TCG_TARGET_HAS_rem_i64          1
diff --git a/tcg/arm/tcg-target.h b/tcg/arm/tcg-target.h
index 09a19c6..2f3ecfd 100644
--- a/tcg/arm/tcg-target.h
+++ b/tcg/arm/tcg-target.h
@@ -123,6 +123,7 @@  extern bool use_idiv_instructions;
 #define TCG_TARGET_HAS_mulsh_i32        0
 #define TCG_TARGET_HAS_div_i32          use_idiv_instructions
 #define TCG_TARGET_HAS_rem_i32          0
+#define TCG_TARGET_HAS_goto_ptr         0
 
 enum {
     TCG_AREG0 = TCG_REG_R6,
diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h
index 4275787..59d9835 100644
--- a/tcg/i386/tcg-target.h
+++ b/tcg/i386/tcg-target.h
@@ -107,6 +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
 
 #if TCG_TARGET_REG_BITS == 64
 #define TCG_TARGET_HAS_extrl_i64_i32    0
diff --git a/tcg/ia64/tcg-target.h b/tcg/ia64/tcg-target.h
index 42aea03..901bb75 100644
--- a/tcg/ia64/tcg-target.h
+++ b/tcg/ia64/tcg-target.h
@@ -173,6 +173,7 @@  typedef enum {
 #define TCG_TARGET_HAS_mulsh_i64        0
 #define TCG_TARGET_HAS_extrl_i64_i32    0
 #define TCG_TARGET_HAS_extrh_i64_i32    0
+#define TCG_TARGET_HAS_goto_ptr         0
 
 #define TCG_TARGET_deposit_i32_valid(ofs, len) ((len) <= 16)
 #define TCG_TARGET_deposit_i64_valid(ofs, len) ((len) <= 16)
diff --git a/tcg/mips/tcg-target.h b/tcg/mips/tcg-target.h
index f46d64a..e3240cf 100644
--- a/tcg/mips/tcg-target.h
+++ b/tcg/mips/tcg-target.h
@@ -130,6 +130,7 @@  extern bool use_mips32r2_instructions;
 #define TCG_TARGET_HAS_muluh_i32        1
 #define TCG_TARGET_HAS_mulsh_i32        1
 #define TCG_TARGET_HAS_bswap32_i32      1
+#define TCG_TARGET_HAS_goto_ptr         0
 
 #if TCG_TARGET_REG_BITS == 64
 #define TCG_TARGET_HAS_add2_i32         0
diff --git a/tcg/ppc/tcg-target.h b/tcg/ppc/tcg-target.h
index abd8b3d..a9aa974 100644
--- a/tcg/ppc/tcg-target.h
+++ b/tcg/ppc/tcg-target.h
@@ -82,6 +82,7 @@  extern bool have_isa_3_00;
 #define TCG_TARGET_HAS_muls2_i32        0
 #define TCG_TARGET_HAS_muluh_i32        1
 #define TCG_TARGET_HAS_mulsh_i32        1
+#define TCG_TARGET_HAS_goto_ptr         0
 
 #if TCG_TARGET_REG_BITS == 64
 #define TCG_TARGET_HAS_add2_i32         0
diff --git a/tcg/s390/tcg-target.h b/tcg/s390/tcg-target.h
index cbdd2a6..6b7bcfb 100644
--- a/tcg/s390/tcg-target.h
+++ b/tcg/s390/tcg-target.h
@@ -92,6 +92,7 @@  extern uint64_t s390_facilities;
 #define TCG_TARGET_HAS_mulsh_i32      0
 #define TCG_TARGET_HAS_extrl_i64_i32  0
 #define TCG_TARGET_HAS_extrh_i64_i32  0
+#define TCG_TARGET_HAS_goto_ptr       0
 
 #define TCG_TARGET_HAS_div2_i64       1
 #define TCG_TARGET_HAS_rot_i64        1
diff --git a/tcg/sparc/tcg-target.h b/tcg/sparc/tcg-target.h
index b8b74f9..9348ddd 100644
--- a/tcg/sparc/tcg-target.h
+++ b/tcg/sparc/tcg-target.h
@@ -123,6 +123,7 @@  extern bool use_vis3_instructions;
 #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_extrl_i64_i32    1
 #define TCG_TARGET_HAS_extrh_i64_i32    1
diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
index 95a39b7..e8a140b 100644
--- a/tcg/tcg-op.c
+++ b/tcg/tcg-op.c
@@ -2587,6 +2587,15 @@  void tcg_gen_goto_tb(unsigned idx)
     tcg_gen_op1i(INDEX_op_goto_tb, idx);
 }
 
+void tcg_gen_goto_ptr(TCGv_ptr ptr)
+{
+    if (TCG_TARGET_HAS_goto_ptr) {
+        tcg_gen_op1i(INDEX_op_goto_ptr, GET_TCGV_PTR(ptr));
+    } else {
+        tcg_gen_exit_tb(0);
+    }
+}
+
 static inline TCGMemOp tcg_canonicalize_memop(TCGMemOp op, bool is64, bool st)
 {
     /* Trigger the asserts within as early as possible.  */
diff --git a/tcg/tcg-op.h b/tcg/tcg-op.h
index c68e300..d65727e 100644
--- a/tcg/tcg-op.h
+++ b/tcg/tcg-op.h
@@ -796,6 +796,15 @@  static inline void tcg_gen_exit_tb(uintptr_t val)
  */
 void tcg_gen_goto_tb(unsigned idx);
 
+/**
+ * tcg_gen_goto_ptr() - output a jump to a host address
+ * @ptr: pointer with the target host address
+ *
+ * Implementing this operation is optional. If the TCG backend does not support
+ * it, this call is equivalent to tcg_gen_exit_tb() with 0 as the argument.
+ */
+void tcg_gen_goto_ptr(TCGv_ptr ptr);
+
 #if TARGET_LONG_BITS == 32
 #define tcg_temp_new() tcg_temp_new_i32()
 #define tcg_global_reg_new tcg_global_reg_new_i32
diff --git a/tcg/tcg-opc.h b/tcg/tcg-opc.h
index f06f894..c64b994 100644
--- a/tcg/tcg-opc.h
+++ b/tcg/tcg-opc.h
@@ -193,6 +193,7 @@  DEF(insn_start, 0, 0, TLADDR_ARGS * TARGET_INSN_START_WORDS,
     TCG_OPF_NOT_PRESENT)
 DEF(exit_tb, 0, 0, 1, TCG_OPF_BB_END)
 DEF(goto_tb, 0, 0, 1, TCG_OPF_BB_END)
+DEF(goto_ptr, 0, 1, 0, TCG_OPF_BB_END)
 
 DEF(qemu_ld_i32, 1, TLADDR_ARGS, 1,
     TCG_OPF_CALL_CLOBBER | TCG_OPF_SIDE_EFFECTS)
diff --git a/tcg/tcg.c b/tcg/tcg.c
index cb898f1..0ea57c0 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -1138,6 +1138,7 @@  void tcg_dump_ops(TCGContext *s)
             }
             switch (c) {
             case INDEX_op_set_label:
+            case INDEX_op_goto_tb:
             case INDEX_op_br:
             case INDEX_op_brcond_i32:
             case INDEX_op_brcond_i64:
diff --git a/tcg/tci/tcg-target.h b/tcg/tci/tcg-target.h
index 838bf3a..0696328 100644
--- a/tcg/tci/tcg-target.h
+++ b/tcg/tci/tcg-target.h
@@ -85,6 +85,7 @@ 
 #define TCG_TARGET_HAS_muls2_i32        0
 #define TCG_TARGET_HAS_muluh_i32        0
 #define TCG_TARGET_HAS_mulsh_i32        0
+#define TCG_TARGET_HAS_goto_ptr         0
 
 #if TCG_TARGET_REG_BITS == 64
 #define TCG_TARGET_HAS_extrl_i64_i32    0