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[PULL 13/38] tcg/tci: Reuse tci_args_l for goto_tb


From: Richard Henderson
Subject: [PULL 13/38] tcg/tci: Reuse tci_args_l for goto_tb
Date: Wed, 17 Mar 2021 09:34:19 -0600

Convert to indirect jumps, as it's less complicated.
Then we just have a pointer to the tb address at which
the chain is stored, from which we read.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/tci/tcg-target.h     | 11 +++--------
 tcg/tci.c                |  8 +++-----
 tcg/tci/tcg-target.c.inc | 13 +++----------
 3 files changed, 9 insertions(+), 23 deletions(-)

diff --git a/tcg/tci/tcg-target.h b/tcg/tci/tcg-target.h
index 9c0021a26f..9285c930a2 100644
--- a/tcg/tci/tcg-target.h
+++ b/tcg/tci/tcg-target.h
@@ -87,7 +87,7 @@
 #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_direct_jump      1
+#define TCG_TARGET_HAS_direct_jump      0
 #define TCG_TARGET_HAS_qemu_st8_i32     0
 
 #if TCG_TARGET_REG_BITS == 64
@@ -174,12 +174,7 @@ void tci_disas(uint8_t opc);
 
 #define TCG_TARGET_HAS_MEMORY_BSWAP     1
 
-static inline void tb_target_set_jmp_target(uintptr_t tc_ptr, uintptr_t jmp_rx,
-                                            uintptr_t jmp_rw, uintptr_t addr)
-{
-    /* patch the branch destination */
-    qatomic_set((int32_t *)jmp_rw, addr - (jmp_rx + 4));
-    /* no need to flush icache explicitly */
-}
+/* not defined -- call should be eliminated at compile time */
+void tb_target_set_jmp_target(uintptr_t, uintptr_t, uintptr_t, uintptr_t);
 
 #endif /* TCG_TARGET_H */
diff --git a/tcg/tci.c b/tcg/tci.c
index 71d6720e22..53e49ccf8e 100644
--- a/tcg/tci.c
+++ b/tcg/tci.c
@@ -818,13 +818,11 @@ uintptr_t QEMU_DISABLE_CFI tcg_qemu_tb_exec(CPUArchState 
*env,
             return (uintptr_t)ptr;
 
         case INDEX_op_goto_tb:
-            /* Jump address is aligned */
-            tb_ptr = QEMU_ALIGN_PTR_UP(tb_ptr, 4);
-            t0 = qatomic_read((int32_t *)tb_ptr);
-            tb_ptr += sizeof(int32_t);
+            tci_args_l(&tb_ptr, &ptr);
             tci_assert(tb_ptr == old_code_ptr + op_size);
-            tb_ptr += (int32_t)t0;
+            tb_ptr = *(void **)ptr;
             continue;
+
         case INDEX_op_qemu_ld_i32:
             t0 = *tb_ptr++;
             taddr = tci_read_ulong(regs, &tb_ptr);
diff --git a/tcg/tci/tcg-target.c.inc b/tcg/tci/tcg-target.c.inc
index ff8040510f..2c64b4f617 100644
--- a/tcg/tci/tcg-target.c.inc
+++ b/tcg/tci/tcg-target.c.inc
@@ -405,16 +405,9 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, const 
TCGArg *args,
         break;
 
     case INDEX_op_goto_tb:
-        if (s->tb_jmp_insn_offset) {
-            /* Direct jump method. */
-            /* Align for atomic patching and thread safety */
-            s->code_ptr = QEMU_ALIGN_PTR_UP(s->code_ptr, 4);
-            s->tb_jmp_insn_offset[args[0]] = tcg_current_code_size(s);
-            tcg_out32(s, 0);
-        } else {
-            /* Indirect jump method. */
-            TODO();
-        }
+        tcg_debug_assert(s->tb_jmp_insn_offset == 0);
+        /* indirect jump method. */
+        tcg_out_i(s, (uintptr_t)(s->tb_jmp_target_addr + args[0]));
         set_jmp_reset_offset(s, args[0]);
         break;
 
-- 
2.25.1




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