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tcg/i386: Use full load/store helpers in user-only mode 

Instead of using helper_unaligned_{ld,st}, use the full load/store helpers.
This will allow the fast path to increase alignment to implement atomicity
while not immediately raising an alignment exception.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2022-11-07 20:51:56 +11:00
parent 1ce12a8c83
commit 30cc7a7e91
1 changed files with 4 additions and 48 deletions
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52
tcg/i386/tcg-target.c.inc
View File

@ -1776,7 +1776,6 @@ typedef struct {
int seg;
} HostAddress;
#if defined(CONFIG_SOFTMMU)
/*
* Because i686 has no register parameters and because x86_64 has xchg
* to handle addr/data register overlap, we have placed all input arguments
@ -1812,7 +1811,7 @@ static bool tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
/* resolve label address */
tcg_patch32(label_ptr[0], s->code_ptr - label_ptr[0] - 4);
if (TARGET_LONG_BITS > TCG_TARGET_REG_BITS) {
if (label_ptr[1]) {
tcg_patch32(label_ptr[1], s->code_ptr - label_ptr[1] - 4);
}
@ -1834,7 +1833,7 @@ static bool tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
/* resolve label address */
tcg_patch32(label_ptr[0], s->code_ptr - label_ptr[0] - 4);
if (TARGET_LONG_BITS > TCG_TARGET_REG_BITS) {
if (label_ptr[1]) {
tcg_patch32(label_ptr[1], s->code_ptr - label_ptr[1] - 4);
}
@ -1844,51 +1843,8 @@ static bool tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
tcg_out_jmp(s, l->raddr);
return true;
}
#else
static bool tcg_out_fail_alignment(TCGContext *s, TCGLabelQemuLdst *l)
{
/* resolve label address */
tcg_patch32(l->label_ptr[0], s->code_ptr - l->label_ptr[0] - 4);
if (TCG_TARGET_REG_BITS == 32) {
int ofs = 0;
tcg_out_st(s, TCG_TYPE_PTR, TCG_AREG0, TCG_REG_ESP, ofs);
ofs += 4;
tcg_out_st(s, TCG_TYPE_I32, l->addrlo_reg, TCG_REG_ESP, ofs);
ofs += 4;
if (TARGET_LONG_BITS == 64) {
tcg_out_st(s, TCG_TYPE_I32, l->addrhi_reg, TCG_REG_ESP, ofs);
ofs += 4;
}
tcg_out_pushi(s, (uintptr_t)l->raddr);
} else {
tcg_out_mov(s, TCG_TYPE_TL, tcg_target_call_iarg_regs[1],
l->addrlo_reg);
tcg_out_mov(s, TCG_TYPE_PTR, tcg_target_call_iarg_regs[0], TCG_AREG0);
tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_RAX, (uintptr_t)l->raddr);
tcg_out_push(s, TCG_REG_RAX);
}
/* "Tail call" to the helper, with the return address back inline. */
tcg_out_jmp(s, (const void *)(l->is_ld ? helper_unaligned_ld
: helper_unaligned_st));
return true;
}
static bool tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
{
return tcg_out_fail_alignment(s, l);
}
static bool tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
{
return tcg_out_fail_alignment(s, l);
}
#ifndef CONFIG_SOFTMMU
static HostAddress x86_guest_base = {
.index = -1
};
@ -1920,7 +1876,7 @@ static inline int setup_guest_base_seg(void)
return 0;
}
#endif /* setup_guest_base_seg */
#endif /* SOFTMMU */
#endif /* !SOFTMMU */
/*
* For softmmu, perform the TLB load and compare.