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tcg-i386: Tidy qemu_ld/st slow path
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Use existing stack space for arguments; don't push/pop.
Use less ifdefs and more C ifs.

Signed-off-by: Richard Henderson <rth@twiddle.net>
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@rth7680
rth7680 committed Aug 26, 2013
1 parent 8023ccd commit c6f29ff
Showing 1 changed file with 74 additions and 91 deletions.
165 changes: 74 additions & 91 deletions tcg/i386/tcg-target.c
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Expand Up @@ -608,6 +608,14 @@ static inline void tcg_out_st(TCGContext *s, TCGType type, TCGReg arg,
tcg_out_modrm_offset(s, opc, arg, arg1, arg2);
}

static inline void tcg_out_sti(TCGContext *s, TCGType type, TCGReg base,
tcg_target_long ofs, tcg_target_long val)
{
int opc = OPC_MOVL_EvIz + (type == TCG_TYPE_I64 ? P_REXW : 0);
tcg_out_modrm_offset(s, opc, 0, base, ofs);
tcg_out32(s, val);
}

static void tcg_out_shifti(TCGContext *s, int subopc, int reg, int count)
{
/* Propagate an opcode prefix, such as P_DATA16. */
Expand Down Expand Up @@ -1463,45 +1471,40 @@ static void add_qemu_ldst_label(TCGContext *s,
/*
* Generate code for the slow path for a load at the end of block
*/
static void tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *label)
static void tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
{
int s_bits;
int opc = label->opc;
int mem_index = label->mem_index;
#if TCG_TARGET_REG_BITS == 32
int stack_adjust;
int addrlo_reg = label->addrlo_reg;
int addrhi_reg = label->addrhi_reg;
#endif
int data_reg = label->datalo_reg;
int data_reg2 = label->datahi_reg;
uint8_t *raddr = label->raddr;
uint8_t **label_ptr = &label->label_ptr[0];

s_bits = opc & 3;
int opc = l->opc;
int s_bits = opc & 3;
TCGReg data_reg;
uint8_t **label_ptr = &l->label_ptr[0];

/* resolve label address */
*(uint32_t *)label_ptr[0] = (uint32_t)(s->code_ptr - label_ptr[0] - 4);
if (TARGET_LONG_BITS > TCG_TARGET_REG_BITS) {
*(uint32_t *)label_ptr[1] = (uint32_t)(s->code_ptr - label_ptr[1] - 4);
}

#if TCG_TARGET_REG_BITS == 32
tcg_out_pushi(s, mem_index);
stack_adjust = 4;
if (TARGET_LONG_BITS == 64) {
tcg_out_push(s, addrhi_reg);
stack_adjust += 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_sti(s, TCG_TYPE_I32, TCG_REG_ESP, ofs, l->mem_index);
} else {
tcg_out_mov(s, TCG_TYPE_I64, 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_push(s, addrlo_reg);
stack_adjust += 4;
tcg_out_push(s, TCG_AREG0);
stack_adjust += 4;
#else
tcg_out_mov(s, TCG_TYPE_I64, 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], mem_index);
#endif

/* Code generation of qemu_ld/st's slow path calling MMU helper
Expand All @@ -1520,18 +1523,10 @@ static void tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *label)
tcg_out8(s, 5);
/* Dummy backward jump having information of fast path'pc for MMU helpers */
tcg_out8(s, OPC_JMP_long);
*(int32_t *)s->code_ptr = (int32_t)(raddr - s->code_ptr - 4);
*(int32_t *)s->code_ptr = (int32_t)(l->raddr - s->code_ptr - 4);
s->code_ptr += 4;

#if TCG_TARGET_REG_BITS == 32
if (stack_adjust == (TCG_TARGET_REG_BITS / 8)) {
/* Pop and discard. This is 2 bytes smaller than the add. */
tcg_out_pop(s, TCG_REG_ECX);
} else if (stack_adjust != 0) {
tcg_out_addi(s, TCG_REG_CALL_STACK, stack_adjust);
}
#endif

data_reg = l->datalo_reg;
switch(opc) {
case 0 | 4:
tcg_out_ext8s(s, data_reg, TCG_REG_EAX, P_REXW);
Expand Down Expand Up @@ -1559,71 +1554,66 @@ static void tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *label)
} else if (data_reg == TCG_REG_EDX) {
/* xchg %edx, %eax */
tcg_out_opc(s, OPC_XCHG_ax_r32 + TCG_REG_EDX, 0, 0, 0);
tcg_out_mov(s, TCG_TYPE_I32, data_reg2, TCG_REG_EAX);
tcg_out_mov(s, TCG_TYPE_I32, l->datahi_reg, TCG_REG_EAX);
} else {
tcg_out_mov(s, TCG_TYPE_I32, data_reg, TCG_REG_EAX);
tcg_out_mov(s, TCG_TYPE_I32, data_reg2, TCG_REG_EDX);
tcg_out_mov(s, TCG_TYPE_I32, l->datahi_reg, TCG_REG_EDX);
}
break;
default:
tcg_abort();
}

/* Jump to the code corresponding to next IR of qemu_st */
tcg_out_jmp(s, (tcg_target_long)raddr);
tcg_out_jmp(s, (tcg_target_long)l->raddr);
}

/*
* Generate code for the slow path for a store at the end of block
*/
static void tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *label)
static void tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
{
int s_bits;
int stack_adjust;
int opc = label->opc;
int mem_index = label->mem_index;
int data_reg = label->datalo_reg;
#if TCG_TARGET_REG_BITS == 32
int data_reg2 = label->datahi_reg;
int addrlo_reg = label->addrlo_reg;
int addrhi_reg = label->addrhi_reg;
#endif
uint8_t *raddr = label->raddr;
uint8_t **label_ptr = &label->label_ptr[0];

s_bits = opc & 3;
int opc = l->opc;
int s_bits = opc & 3;
uint8_t **label_ptr = &l->label_ptr[0];

/* resolve label address */
*(uint32_t *)label_ptr[0] = (uint32_t)(s->code_ptr - label_ptr[0] - 4);
if (TARGET_LONG_BITS > TCG_TARGET_REG_BITS) {
*(uint32_t *)label_ptr[1] = (uint32_t)(s->code_ptr - label_ptr[1] - 4);
}

#if TCG_TARGET_REG_BITS == 32
tcg_out_pushi(s, mem_index);
stack_adjust = 4;
if (opc == 3) {
tcg_out_push(s, data_reg2);
stack_adjust += 4;
}
tcg_out_push(s, data_reg);
stack_adjust += 4;
if (TARGET_LONG_BITS == 64) {
tcg_out_push(s, addrhi_reg);
stack_adjust += 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_st(s, TCG_TYPE_I32, l->datalo_reg, TCG_REG_ESP, ofs);
ofs += 4;

if (opc == 3) {
tcg_out_st(s, TCG_TYPE_I32, l->datahi_reg, TCG_REG_ESP, ofs);
ofs += 4;
}

tcg_out_sti(s, TCG_TYPE_I32, TCG_REG_ESP, ofs, l->mem_index);
} else {
tcg_out_mov(s, TCG_TYPE_I64, 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),
tcg_target_call_iarg_regs[2], l->datalo_reg);
tcg_out_movi(s, TCG_TYPE_I32, tcg_target_call_iarg_regs[3],
l->mem_index);
}
tcg_out_push(s, addrlo_reg);
stack_adjust += 4;
tcg_out_push(s, TCG_AREG0);
stack_adjust += 4;
#else
tcg_out_mov(s, TCG_TYPE_I64, 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),
tcg_target_call_iarg_regs[2], data_reg);
tcg_out_movi(s, TCG_TYPE_I32, tcg_target_call_iarg_regs[3], mem_index);
stack_adjust = 0;
#endif

/* Code generation of qemu_ld/st's slow path calling MMU helper
Expand All @@ -1642,18 +1632,11 @@ static void tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *label)
tcg_out8(s, 5);
/* Dummy backward jump having information of fast path'pc for MMU helpers */
tcg_out8(s, OPC_JMP_long);
*(int32_t *)s->code_ptr = (int32_t)(raddr - s->code_ptr - 4);
*(int32_t *)s->code_ptr = (int32_t)(l->raddr - s->code_ptr - 4);
s->code_ptr += 4;

if (stack_adjust == (TCG_TARGET_REG_BITS / 8)) {
/* Pop and discard. This is 2 bytes smaller than the add. */
tcg_out_pop(s, TCG_REG_ECX);
} else if (stack_adjust != 0) {
tcg_out_addi(s, TCG_REG_CALL_STACK, stack_adjust);
}

/* Jump to the code corresponding to next IR of qemu_st */
tcg_out_jmp(s, (tcg_target_long)raddr);
tcg_out_jmp(s, (tcg_target_long)l->raddr);
}

/*
Expand Down

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