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tcg-i386: Don't perform GETPC adjustment in TCG code

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Since we now perform it inside the helper, no need to do it here.
This also lets us perform a tail-call from the store slow path to
the helper.

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Richard Henderson 2013-08-27 10:47:49 -07:00
parent 0f842f8a24
commit 5bcebc253c
1 changed files with 14 additions and 19 deletions
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33
tcg/i386/tcg-target.c
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@ -1481,12 +1481,6 @@ static void add_qemu_ldst_label(TCGContext *s,
}
}
/* See the GETPC definition in include/exec/exec-all.h. */
static inline uintptr_t do_getpc(uint8_t *raddr)
{
return (uintptr_t)raddr - 1;
}
/*
* Generate code for the slow path for a load at the end of block
*/
@ -1520,14 +1514,14 @@ static void tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
tcg_out_sti(s, TCG_TYPE_I32, TCG_REG_ESP, ofs, l->mem_index);
ofs += 4;
tcg_out_sti(s, TCG_TYPE_I32, TCG_REG_ESP, ofs, do_getpc(l->raddr));
tcg_out_sti(s, TCG_TYPE_I32, TCG_REG_ESP, ofs, (uintptr_t)l->raddr);
} else {
tcg_out_mov(s, TCG_TYPE_PTR, tcg_target_call_iarg_regs[0], TCG_AREG0);
/* The second argument is already loaded with addrlo. */
tcg_out_movi(s, TCG_TYPE_I32, tcg_target_call_iarg_regs[2],
l->mem_index);
tcg_out_movi(s, TCG_TYPE_PTR, tcg_target_call_iarg_regs[3],
do_getpc(l->raddr));
(uintptr_t)l->raddr);
}
tcg_out_calli(s, (uintptr_t)qemu_ld_helpers[s_bits]);
@ -1582,6 +1576,7 @@ static void tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
int opc = l->opc;
int s_bits = opc & 3;
uint8_t **label_ptr = &l->label_ptr[0];
TCGReg retaddr;
/* resolve label address */
*(uint32_t *)label_ptr[0] = (uint32_t)(s->code_ptr - label_ptr[0] - 4);
@ -1614,10 +1609,10 @@ static void tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
tcg_out_sti(s, TCG_TYPE_I32, TCG_REG_ESP, ofs, l->mem_index);
ofs += 4;
tcg_out_sti(s, TCG_TYPE_I32, TCG_REG_ESP, ofs, do_getpc(l->raddr));
retaddr = TCG_REG_EAX;
tcg_out_movi(s, TCG_TYPE_I32, retaddr, (uintptr_t)l->raddr);
tcg_out_st(s, TCG_TYPE_I32, retaddr, TCG_REG_ESP, ofs);
} else {
uintptr_t pc;
tcg_out_mov(s, TCG_TYPE_PTR, tcg_target_call_iarg_regs[0], TCG_AREG0);
/* The second argument is already loaded with addrlo. */
tcg_out_mov(s, (opc == 3 ? TCG_TYPE_I64 : TCG_TYPE_I32),
@ -1625,19 +1620,19 @@ static void tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
tcg_out_movi(s, TCG_TYPE_I32, tcg_target_call_iarg_regs[3],
l->mem_index);
pc = do_getpc(l->raddr);
if (ARRAY_SIZE(tcg_target_call_iarg_regs) > 4) {
tcg_out_movi(s, TCG_TYPE_PTR, tcg_target_call_iarg_regs[4], pc);
} else if (pc == (int32_t)pc) {
tcg_out_sti(s, TCG_TYPE_PTR, TCG_REG_ESP, 0, pc);
retaddr = tcg_target_call_iarg_regs[4];
tcg_out_movi(s, TCG_TYPE_PTR, retaddr, (uintptr_t)l->raddr);
} else {
tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_RAX, pc);
tcg_out_st(s, TCG_TYPE_PTR, TCG_REG_RAX, TCG_REG_ESP, 0);
retaddr = TCG_REG_RAX;
tcg_out_movi(s, TCG_TYPE_PTR, retaddr, (uintptr_t)l->raddr);
tcg_out_st(s, TCG_TYPE_PTR, retaddr, TCG_REG_ESP, 0);
}
}
tcg_out_calli(s, (uintptr_t)qemu_st_helpers[s_bits]);
tcg_out_jmp(s, (uintptr_t)l->raddr);
/* "Tail call" to the helper, with the return address back inline. */
tcg_out_push(s, retaddr);
tcg_out_jmp(s, (uintptr_t)qemu_st_helpers[s_bits]);
}
/*