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tcg/i386: Convert tcg_out_qemu_st_slow_path

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Use tcg_out_st_helper_args.  This eliminates the use of a tail call to
the store helper.  This may or may not be an improvement, depending on
the call/return branch prediction of the host microarchitecture.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2023-04-09 23:08:12 -07:00
parent da8ab70ad1
commit 0036e54e7a
1 changed files with 4 additions and 53 deletions
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57
tcg/i386/tcg-target.c.inc
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@ -1854,11 +1854,8 @@ static bool tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
*/
static bool tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
{
MemOpIdx oi = l->oi;
MemOp opc = get_memop(oi);
MemOp s_bits = opc & MO_SIZE;
MemOp opc = get_memop(l->oi);
tcg_insn_unit **label_ptr = &l->label_ptr[0];
TCGReg retaddr;
/* resolve label address */
tcg_patch32(label_ptr[0], s->code_ptr - label_ptr[0] - 4);
@ -1866,56 +1863,10 @@ static bool tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
tcg_patch32(label_ptr[1], s->code_ptr - label_ptr[1] - 4);
}
if (TCG_TARGET_REG_BITS == 32) {
int ofs = 0;
tcg_out_st_helper_args(s, l, &ldst_helper_param);
tcg_out_branch(s, 1, qemu_st_helpers[opc & (MO_BSWAP | MO_SIZE)]);
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_st(s, TCG_TYPE_I32, l->datalo_reg, TCG_REG_ESP, ofs);
ofs += 4;
if (s_bits == MO_64) {
tcg_out_st(s, TCG_TYPE_I32, l->datahi_reg, TCG_REG_ESP, ofs);
ofs += 4;
}
tcg_out_sti(s, TCG_TYPE_I32, oi, TCG_REG_ESP, ofs);
ofs += 4;
retaddr = TCG_REG_EAX;
tcg_out_movi(s, TCG_TYPE_PTR, retaddr, (uintptr_t)l->raddr);
tcg_out_st(s, TCG_TYPE_PTR, retaddr, TCG_REG_ESP, ofs);
} else {
tcg_out_mov(s, TCG_TYPE_PTR, tcg_target_call_iarg_regs[0], TCG_AREG0);
tcg_out_mov(s, TCG_TYPE_TL, tcg_target_call_iarg_regs[1],
l->addrlo_reg);
tcg_out_mov(s, (s_bits == MO_64 ? TCG_TYPE_I64 : TCG_TYPE_I32),
tcg_target_call_iarg_regs[2], l->datalo_reg);
tcg_out_movi(s, TCG_TYPE_I32, tcg_target_call_iarg_regs[3], oi);
if (ARRAY_SIZE(tcg_target_call_iarg_regs) > 4) {
retaddr = tcg_target_call_iarg_regs[4];
tcg_out_movi(s, TCG_TYPE_PTR, retaddr, (uintptr_t)l->raddr);
} else {
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,
TCG_TARGET_CALL_STACK_OFFSET);
}
}
/* "Tail call" to the helper, with the return address back inline. */
tcg_out_push(s, retaddr);
tcg_out_jmp(s, qemu_st_helpers[opc & (MO_BSWAP | MO_SIZE)]);
tcg_out_jmp(s, l->raddr);
return true;
}
#else