tcg/tci: Reuse tci_args_l for goto_tb

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>
This commit is contained in:
Richard Henderson 2021-01-29 22:11:43 -10:00
parent 158d38737b
commit 1670a2b9bb
3 changed files with 9 additions and 23 deletions

View file

@ -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);

View file

@ -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;

View file

@ -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 */