@@ -101,6 +101,7 @@ extern bool have_bmi1;
extern bool have_popcnt;
extern bool have_avx1;
extern bool have_avx2;
+extern bool have_movbe;
/* optional instructions */
#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_HAS_MEMORY_BSWAP 1
+#define TCG_TARGET_HAS_MEMORY_BSWAP have_movbe
#ifdef CONFIG_SOFTMMU
#define TCG_TARGET_NEED_LDST_LABELS
@@ -154,13 +154,12 @@ bool have_bmi1;
bool have_popcnt;
bool have_avx1;
bool have_avx2;
+bool have_movbe;
#ifdef CONFIG_CPUID_H
-static bool have_movbe;
static bool have_bmi2;
static bool have_lzcnt;
#else
-# define have_movbe 0
# define have_bmi2 0
# define have_lzcnt 0
#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,
int seg, bool is64, MemOp memop)
{
- const MemOp real_bswap = memop & MO_BSWAP;
- MemOp bswap = real_bswap;
+ bool use_movbe = false;
int rexw = is64 * P_REXW;
int movop = OPC_MOVL_GvEv;
- if (have_movbe && real_bswap) {
- bswap = 0;
+ /* Do big-endian loads with movbe. */
+ if (memop & MO_BSWAP) {
+ tcg_debug_assert(have_movbe);
+ use_movbe = true;
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);
break;
case MO_UW:
- tcg_out_modrm_sib_offset(s, OPC_MOVZWL + seg, datalo,
- base, index, 0, ofs);
- if (real_bswap) {
- tcg_out_rolw_8(s, datalo);
- }
- break;
- case MO_SW:
- if (real_bswap) {
- if (have_movbe) {
+ if (use_movbe) {
+ /* There is no extending movbe; only low 16-bits are modified. */
+ if (datalo != base && datalo != index) {
+ /* XOR breaks dependency chains. */
+ tgen_arithr(s, ARITH_XOR, datalo, datalo);
tcg_out_modrm_sib_offset(s, OPC_MOVBE_GyMy + P_DATA16 + seg,
datalo, base, index, 0, ofs);
} else {
- tcg_out_modrm_sib_offset(s, OPC_MOVZWL + seg, datalo,
- base, index, 0, ofs);
- tcg_out_rolw_8(s, datalo);
+ tcg_out_modrm_sib_offset(s, OPC_MOVBE_GyMy + P_DATA16 + seg,
+ datalo, base, index, 0, ofs);
+ 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 {
tcg_out_modrm_sib_offset(s, OPC_MOVSWL + rexw + seg,
datalo, base, index, 0, ofs);
@@ -2030,18 +2035,12 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
break;
case MO_UL:
tcg_out_modrm_sib_offset(s, movop + seg, datalo, base, index, 0, ofs);
- if (bswap) {
- tcg_out_bswap32(s, datalo);
- }
break;
#if TCG_TARGET_REG_BITS == 64
case MO_SL:
- if (real_bswap) {
- tcg_out_modrm_sib_offset(s, movop + seg, datalo,
+ if (use_movbe) {
+ tcg_out_modrm_sib_offset(s, OPC_MOVBE_GyMy + seg, datalo,
base, index, 0, ofs);
- if (bswap) {
- tcg_out_bswap32(s, datalo);
- }
tcg_out_ext32s(s, datalo, datalo);
} else {
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) {
tcg_out_modrm_sib_offset(s, movop + P_REXW + seg, datalo,
base, index, 0, ofs);
- if (bswap) {
- tcg_out_bswap64(s, datalo);
- }
} else {
- if (real_bswap) {
- int t = datalo;
+ if (use_movbe) {
+ TCGReg t = datalo;
datalo = datahi;
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,
base, index, 0, ofs);
}
- if (bswap) {
- tcg_out_bswap32(s, datalo);
- tcg_out_bswap32(s, datahi);
- }
}
break;
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,
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 MemOp real_bswap = memop & MO_BSWAP;
- MemOp bswap = real_bswap;
+ bool use_movbe = false;
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;
}
switch (memop & MO_SIZE) {
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) {
tcg_out_mov(s, TCG_TYPE_I32, scratch, datalo);
datalo = scratch;
@@ -2154,43 +2149,19 @@ static void tcg_out_qemu_st_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
datalo, base, index, 0, ofs);
break;
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,
base, index, 0, ofs);
break;
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);
break;
case MO_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,
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 {
- if (real_bswap) {
- int t = datalo;
+ if (use_movbe) {
+ TCGReg t = datalo;
datalo = datahi;
datahi = t;
}
@@ -2201,7 +2172,7 @@ static void tcg_out_qemu_st_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
}
break;
default:
- tcg_abort();
+ g_assert_not_reached();
}
}