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tcg/i386: Adjust TCG_TARGET_HAS_MEMORY_BSWAP

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Always true when movbe is available, otherwise leave
this to generic code.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2018-11-20 10:26:40 +01:00
parent 655a650aca
commit d2ef1b83a7
2 changed files with 47 additions and 75 deletions
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119
tcg/i386/tcg-target.c.inc
View File

@ -154,13 +154,12 @@ bool have_bmi1;
bool have_popcnt; bool have_popcnt;
bool have_avx1; bool have_avx1;
bool have_avx2; bool have_avx2;
bool have_movbe;
#ifdef CONFIG_CPUID_H #ifdef CONFIG_CPUID_H
static bool have_movbe;
static bool have_bmi2; static bool have_bmi2;
static bool have_lzcnt; static bool have_lzcnt;
#else #else
# define have_movbe 0
# define have_bmi2 0 # define have_bmi2 0
# define have_lzcnt 0 # define have_lzcnt 0
#endif #endif
@ -1986,13 +1985,14 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
TCGReg base, int index, intptr_t ofs, TCGReg base, int index, intptr_t ofs,
int seg, bool is64, MemOp memop) int seg, bool is64, MemOp memop)
{ {
const MemOp real_bswap = memop & MO_BSWAP; bool use_movbe = false;
MemOp bswap = real_bswap;
int rexw = is64 * P_REXW; int rexw = is64 * P_REXW;
int movop = OPC_MOVL_GvEv; int movop = OPC_MOVL_GvEv;
if (have_movbe && real_bswap) { /* Do big-endian loads with movbe. */
bswap = 0; if (memop & MO_BSWAP) {
tcg_debug_assert(have_movbe);
use_movbe = true;
movop = OPC_MOVBE_GyMy; movop = OPC_MOVBE_GyMy;
} }
@ -2006,23 +2006,28 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
base, index, 0, ofs); base, index, 0, ofs);
break; break;
case MO_UW: case MO_UW:
tcg_out_modrm_sib_offset(s, OPC_MOVZWL + seg, datalo, if (use_movbe) {
base, index, 0, ofs); /* There is no extending movbe; only low 16-bits are modified. */
if (real_bswap) { if (datalo != base && datalo != index) {
tcg_out_rolw_8(s, datalo); /* XOR breaks dependency chains. */
} tgen_arithr(s, ARITH_XOR, datalo, datalo);
break;
case MO_SW:
if (real_bswap) {
if (have_movbe) {
tcg_out_modrm_sib_offset(s, OPC_MOVBE_GyMy + P_DATA16 + seg, tcg_out_modrm_sib_offset(s, OPC_MOVBE_GyMy + P_DATA16 + seg,
datalo, base, index, 0, ofs); datalo, base, index, 0, ofs);
} else { } else {
tcg_out_modrm_sib_offset(s, OPC_MOVZWL + seg, datalo, tcg_out_modrm_sib_offset(s, OPC_MOVBE_GyMy + P_DATA16 + seg,
base, index, 0, ofs); datalo, base, index, 0, ofs);
tcg_out_rolw_8(s, datalo); tcg_out_ext16u(s, datalo, datalo);
} }
tcg_out_modrm(s, OPC_MOVSWL + rexw, datalo, datalo); } else {
tcg_out_modrm_sib_offset(s, OPC_MOVZWL + seg, datalo,
base, index, 0, ofs);
}
break;
case MO_SW:
if (use_movbe) {
tcg_out_modrm_sib_offset(s, OPC_MOVBE_GyMy + P_DATA16 + seg,
datalo, base, index, 0, ofs);
tcg_out_ext16s(s, datalo, datalo, rexw);
} else { } else {
tcg_out_modrm_sib_offset(s, OPC_MOVSWL + rexw + seg, tcg_out_modrm_sib_offset(s, OPC_MOVSWL + rexw + seg,
datalo, base, index, 0, ofs); datalo, base, index, 0, ofs);
@ -2030,18 +2035,12 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
break; break;
case MO_UL: case MO_UL:
tcg_out_modrm_sib_offset(s, movop + seg, datalo, base, index, 0, ofs); tcg_out_modrm_sib_offset(s, movop + seg, datalo, base, index, 0, ofs);
if (bswap) {
tcg_out_bswap32(s, datalo);
}
break; break;
#if TCG_TARGET_REG_BITS == 64 #if TCG_TARGET_REG_BITS == 64
case MO_SL: case MO_SL:
if (real_bswap) { if (use_movbe) {
tcg_out_modrm_sib_offset(s, movop + seg, datalo, tcg_out_modrm_sib_offset(s, OPC_MOVBE_GyMy + seg, datalo,
base, index, 0, ofs); base, index, 0, ofs);
if (bswap) {
tcg_out_bswap32(s, datalo);
}
tcg_out_ext32s(s, datalo, datalo); tcg_out_ext32s(s, datalo, datalo);
} else { } else {
tcg_out_modrm_sib_offset(s, OPC_MOVSLQ + seg, datalo, tcg_out_modrm_sib_offset(s, OPC_MOVSLQ + seg, datalo,
@ -2053,12 +2052,9 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
if (TCG_TARGET_REG_BITS == 64) { if (TCG_TARGET_REG_BITS == 64) {
tcg_out_modrm_sib_offset(s, movop + P_REXW + seg, datalo, tcg_out_modrm_sib_offset(s, movop + P_REXW + seg, datalo,
base, index, 0, ofs); base, index, 0, ofs);
if (bswap) {
tcg_out_bswap64(s, datalo);
}
} else { } else {
if (real_bswap) { if (use_movbe) {
int t = datalo; TCGReg t = datalo;
datalo = datahi; datalo = datahi;
datahi = t; datahi = t;
} }
@ -2073,14 +2069,10 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
tcg_out_modrm_sib_offset(s, movop + seg, datalo, tcg_out_modrm_sib_offset(s, movop + seg, datalo,
base, index, 0, ofs); base, index, 0, ofs);
} }
if (bswap) {
tcg_out_bswap32(s, datalo);
tcg_out_bswap32(s, datahi);
}
} }
break; break;
default: default:
tcg_abort(); g_assert_not_reached();
} }
} }
@ -2128,24 +2120,27 @@ static void tcg_out_qemu_st_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
TCGReg base, int index, intptr_t ofs, TCGReg base, int index, intptr_t ofs,
int seg, MemOp memop) int seg, MemOp memop)
{ {
/* ??? Ideally we wouldn't need a scratch register. For user-only,
we could perform the bswap twice to restore the original value
instead of moving to the scratch. But as it is, the L constraint
means that TCG_REG_L0 is definitely free here. */
const TCGReg scratch = TCG_REG_L0; const TCGReg scratch = TCG_REG_L0;
const MemOp real_bswap = memop & MO_BSWAP; bool use_movbe = false;
MemOp bswap = real_bswap;
int movop = OPC_MOVL_EvGv; int movop = OPC_MOVL_EvGv;
if (have_movbe && real_bswap) { /*
bswap = 0; * Do big-endian stores with movbe or softmmu.
* User-only without movbe will have its swapping done generically.
*/
if (memop & MO_BSWAP) {
tcg_debug_assert(have_movbe);
use_movbe = true;
movop = OPC_MOVBE_MyGy; movop = OPC_MOVBE_MyGy;
} }
switch (memop & MO_SIZE) { switch (memop & MO_SIZE) {
case MO_8: case MO_8:
/* In 32-bit mode, 8-bit stores can only happen from [abcd]x. /*
Use the scratch register if necessary. */ * In 32-bit mode, 8-bit stores can only happen from [abcd]x.
* TODO: Adjust constraints such that this is is forced,
* then we won't need a scratch at all for user-only.
*/
if (TCG_TARGET_REG_BITS == 32 && datalo >= 4) { if (TCG_TARGET_REG_BITS == 32 && datalo >= 4) {
tcg_out_mov(s, TCG_TYPE_I32, scratch, datalo); tcg_out_mov(s, TCG_TYPE_I32, scratch, datalo);
datalo = scratch; datalo = scratch;
@ -2154,43 +2149,19 @@ static void tcg_out_qemu_st_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
datalo, base, index, 0, ofs); datalo, base, index, 0, ofs);
break; break;
case MO_16: case MO_16:
if (bswap) {
tcg_out_mov(s, TCG_TYPE_I32, scratch, datalo);
tcg_out_rolw_8(s, scratch);
datalo = scratch;
}
tcg_out_modrm_sib_offset(s, movop + P_DATA16 + seg, datalo, tcg_out_modrm_sib_offset(s, movop + P_DATA16 + seg, datalo,
base, index, 0, ofs); base, index, 0, ofs);
break; break;
case MO_32: case MO_32:
if (bswap) {
tcg_out_mov(s, TCG_TYPE_I32, scratch, datalo);
tcg_out_bswap32(s, scratch);
datalo = scratch;
}
tcg_out_modrm_sib_offset(s, movop + seg, datalo, base, index, 0, ofs); tcg_out_modrm_sib_offset(s, movop + seg, datalo, base, index, 0, ofs);
break; break;
case MO_64: case MO_64:
if (TCG_TARGET_REG_BITS == 64) { if (TCG_TARGET_REG_BITS == 64) {
if (bswap) {
tcg_out_mov(s, TCG_TYPE_I64, scratch, datalo);
tcg_out_bswap64(s, scratch);
datalo = scratch;
}
tcg_out_modrm_sib_offset(s, movop + P_REXW + seg, datalo, tcg_out_modrm_sib_offset(s, movop + P_REXW + seg, datalo,
base, index, 0, ofs); base, index, 0, ofs);
} else if (bswap) {
tcg_out_mov(s, TCG_TYPE_I32, scratch, datahi);
tcg_out_bswap32(s, scratch);
tcg_out_modrm_sib_offset(s, OPC_MOVL_EvGv + seg, scratch,
base, index, 0, ofs);
tcg_out_mov(s, TCG_TYPE_I32, scratch, datalo);
tcg_out_bswap32(s, scratch);
tcg_out_modrm_sib_offset(s, OPC_MOVL_EvGv + seg, scratch,
base, index, 0, ofs + 4);
} else { } else {
if (real_bswap) { if (use_movbe) {
int t = datalo; TCGReg t = datalo;
datalo = datahi; datalo = datahi;
datahi = t; datahi = t;
} }
@ -2201,7 +2172,7 @@ static void tcg_out_qemu_st_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
} }
break; break;
default: default:
tcg_abort(); g_assert_not_reached();
} }
} }

3
tcg/i386/tcg-target.h
View File

@ -101,6 +101,7 @@ extern bool have_bmi1;
extern bool have_popcnt; extern bool have_popcnt;
extern bool have_avx1; extern bool have_avx1;
extern bool have_avx2; extern bool have_avx2;
extern bool have_movbe;
/* optional instructions */ /* optional instructions */
#define TCG_TARGET_HAS_div2_i32 1 #define TCG_TARGET_HAS_div2_i32 1
@ -225,7 +226,7 @@ static inline void tb_target_set_jmp_target(uintptr_t tc_ptr,
#define TCG_TARGET_DEFAULT_MO (TCG_MO_ALL & ~TCG_MO_ST_LD) #define TCG_TARGET_DEFAULT_MO (TCG_MO_ALL & ~TCG_MO_ST_LD)
#define TCG_TARGET_HAS_MEMORY_BSWAP 1 #define TCG_TARGET_HAS_MEMORY_BSWAP have_movbe
#ifdef CONFIG_SOFTMMU #ifdef CONFIG_SOFTMMU
#define TCG_TARGET_NEED_LDST_LABELS #define TCG_TARGET_NEED_LDST_LABELS