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-rw-r--r--tcg/i386/tcg-target.c117
1 files changed, 80 insertions, 37 deletions
diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c
index 7161fe0dd4..db0039a8f1 100644
--- a/tcg/i386/tcg-target.c
+++ b/tcg/i386/tcg-target.c
@@ -99,18 +99,31 @@ static const int tcg_target_call_oarg_regs[] = {
# define TCG_REG_L1 TCG_REG_EDX
#endif
+/* The host compiler should supply <cpuid.h> to enable runtime features
+ detection, as we're not going to go so far as our own inline assembly.
+ If not available, default values will be assumed. */
+#if defined(CONFIG_CPUID_H)
+#include <cpuid.h>
+#endif
+
/* For 32-bit, we are going to attempt to determine at runtime whether cmov
- is available. However, the host compiler must supply <cpuid.h>, as we're
- not going to go so far as our own inline assembly. */
+ is available. */
#if TCG_TARGET_REG_BITS == 64
# define have_cmov 1
#elif defined(CONFIG_CPUID_H)
-#include <cpuid.h>
static bool have_cmov;
#else
# define have_cmov 0
#endif
+/* If bit_MOVBE is defined in cpuid.h (added in GCC version 4.6), we are
+ going to attempt to determine at runtime whether movbe is available. */
+#if defined(CONFIG_CPUID_H) && defined(bit_MOVBE)
+static bool have_movbe;
+#else
+# define have_movbe 0
+#endif
+
static uint8_t *tb_ret_addr;
static void patch_reloc(uint8_t *code_ptr, int type,
@@ -280,6 +293,8 @@ static inline int tcg_target_const_match(tcg_target_long val,
#define OPC_MOVB_EvIz (0xc6)
#define OPC_MOVL_EvIz (0xc7)
#define OPC_MOVL_Iv (0xb8)
+#define OPC_MOVBE_GyMy (0xf0 | P_EXT38)
+#define OPC_MOVBE_MyGy (0xf1 | P_EXT38)
#define OPC_MOVSBL (0xbe | P_EXT)
#define OPC_MOVSWL (0xbf | P_EXT)
#define OPC_MOVSLQ (0x63 | P_REXW)
@@ -1344,7 +1359,14 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
TCGReg base, intptr_t ofs, int seg,
TCGMemOp memop)
{
- const TCGMemOp bswap = memop & MO_BSWAP;
+ const TCGMemOp real_bswap = memop & MO_BSWAP;
+ TCGMemOp bswap = real_bswap;
+ int movop = OPC_MOVL_GvEv;
+
+ if (have_movbe && real_bswap) {
+ bswap = 0;
+ movop = OPC_MOVBE_GyMy;
+ }
switch (memop & MO_SSIZE) {
case MO_UB:
@@ -1355,14 +1377,19 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
break;
case MO_UW:
tcg_out_modrm_offset(s, OPC_MOVZWL + seg, datalo, base, ofs);
- if (bswap) {
+ if (real_bswap) {
tcg_out_rolw_8(s, datalo);
}
break;
case MO_SW:
- if (bswap) {
- tcg_out_modrm_offset(s, OPC_MOVZWL + seg, datalo, base, ofs);
- tcg_out_rolw_8(s, datalo);
+ if (real_bswap) {
+ if (have_movbe) {
+ tcg_out_modrm_offset(s, OPC_MOVBE_GyMy + P_DATA16 + seg,
+ datalo, base, ofs);
+ } else {
+ tcg_out_modrm_offset(s, OPC_MOVZWL + seg, datalo, base, ofs);
+ tcg_out_rolw_8(s, datalo);
+ }
tcg_out_modrm(s, OPC_MOVSWL + P_REXW, datalo, datalo);
} else {
tcg_out_modrm_offset(s, OPC_MOVSWL + P_REXW + seg,
@@ -1370,16 +1397,18 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
}
break;
case MO_UL:
- tcg_out_modrm_offset(s, OPC_MOVL_GvEv + seg, datalo, base, ofs);
+ tcg_out_modrm_offset(s, movop + seg, datalo, base, ofs);
if (bswap) {
tcg_out_bswap32(s, datalo);
}
break;
#if TCG_TARGET_REG_BITS == 64
case MO_SL:
- if (bswap) {
- tcg_out_modrm_offset(s, OPC_MOVL_GvEv + seg, datalo, base, ofs);
- tcg_out_bswap32(s, datalo);
+ if (real_bswap) {
+ tcg_out_modrm_offset(s, movop + seg, datalo, base, ofs);
+ if (bswap) {
+ tcg_out_bswap32(s, datalo);
+ }
tcg_out_ext32s(s, datalo, datalo);
} else {
tcg_out_modrm_offset(s, OPC_MOVSLQ + seg, datalo, base, ofs);
@@ -1388,27 +1417,22 @@ static void tcg_out_qemu_ld_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
#endif
case MO_Q:
if (TCG_TARGET_REG_BITS == 64) {
- tcg_out_modrm_offset(s, OPC_MOVL_GvEv + P_REXW + seg,
- datalo, base, ofs);
+ tcg_out_modrm_offset(s, movop + P_REXW + seg, datalo, base, ofs);
if (bswap) {
tcg_out_bswap64(s, datalo);
}
} else {
- if (bswap) {
+ if (real_bswap) {
int t = datalo;
datalo = datahi;
datahi = t;
}
if (base != datalo) {
- tcg_out_modrm_offset(s, OPC_MOVL_GvEv + seg,
- datalo, base, ofs);
- tcg_out_modrm_offset(s, OPC_MOVL_GvEv + seg,
- datahi, base, ofs + 4);
+ tcg_out_modrm_offset(s, movop + seg, datalo, base, ofs);
+ tcg_out_modrm_offset(s, movop + seg, datahi, base, ofs + 4);
} else {
- tcg_out_modrm_offset(s, OPC_MOVL_GvEv + seg,
- datahi, base, ofs + 4);
- tcg_out_modrm_offset(s, OPC_MOVL_GvEv + seg,
- datalo, base, ofs);
+ tcg_out_modrm_offset(s, movop + seg, datahi, base, ofs + 4);
+ tcg_out_modrm_offset(s, movop + seg, datalo, base, ofs);
}
if (bswap) {
tcg_out_bswap32(s, datalo);
@@ -1484,13 +1508,19 @@ static void tcg_out_qemu_st_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
TCGReg base, intptr_t ofs, int seg,
TCGMemOp memop)
{
- const TCGMemOp bswap = memop & MO_BSWAP;
-
/* ??? 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 TCGMemOp real_bswap = memop & MO_BSWAP;
+ TCGMemOp bswap = real_bswap;
+ int movop = OPC_MOVL_EvGv;
+
+ if (have_movbe && real_bswap) {
+ bswap = 0;
+ movop = OPC_MOVBE_MyGy;
+ }
switch (memop & MO_SIZE) {
case MO_8:
@@ -1509,8 +1539,7 @@ static void tcg_out_qemu_st_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
tcg_out_rolw_8(s, scratch);
datalo = scratch;
}
- tcg_out_modrm_offset(s, OPC_MOVL_EvGv + P_DATA16 + seg,
- datalo, base, ofs);
+ tcg_out_modrm_offset(s, movop + P_DATA16 + seg, datalo, base, ofs);
break;
case MO_32:
if (bswap) {
@@ -1518,7 +1547,7 @@ static void tcg_out_qemu_st_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
tcg_out_bswap32(s, scratch);
datalo = scratch;
}
- tcg_out_modrm_offset(s, OPC_MOVL_EvGv + seg, datalo, base, ofs);
+ tcg_out_modrm_offset(s, movop + seg, datalo, base, ofs);
break;
case MO_64:
if (TCG_TARGET_REG_BITS == 64) {
@@ -1527,8 +1556,7 @@ static void tcg_out_qemu_st_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
tcg_out_bswap64(s, scratch);
datalo = scratch;
}
- tcg_out_modrm_offset(s, OPC_MOVL_EvGv + P_REXW + seg,
- datalo, base, ofs);
+ tcg_out_modrm_offset(s, movop + P_REXW + seg, datalo, base, ofs);
} else if (bswap) {
tcg_out_mov(s, TCG_TYPE_I32, scratch, datahi);
tcg_out_bswap32(s, scratch);
@@ -1537,8 +1565,13 @@ static void tcg_out_qemu_st_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
tcg_out_bswap32(s, scratch);
tcg_out_modrm_offset(s, OPC_MOVL_EvGv + seg, scratch, base, ofs+4);
} else {
- tcg_out_modrm_offset(s, OPC_MOVL_EvGv + seg, datalo, base, ofs);
- tcg_out_modrm_offset(s, OPC_MOVL_EvGv + seg, datahi, base, ofs+4);
+ if (real_bswap) {
+ int t = datalo;
+ datalo = datahi;
+ datahi = t;
+ }
+ tcg_out_modrm_offset(s, movop + seg, datalo, base, ofs);
+ tcg_out_modrm_offset(s, movop + seg, datahi, base, ofs+4);
}
break;
default:
@@ -2165,13 +2198,23 @@ static void tcg_target_qemu_prologue(TCGContext *s)
static void tcg_target_init(TCGContext *s)
{
- /* For 32-bit, 99% certainty that we're running on hardware that supports
- cmov, but we still need to check. In case cmov is not available, we'll
- use a small forward branch. */
-#ifndef have_cmov
+#if !(defined(have_cmov) && defined(have_movbe))
{
unsigned a, b, c, d;
- have_cmov = (__get_cpuid(1, &a, &b, &c, &d) && (d & bit_CMOV));
+ int ret = __get_cpuid(1, &a, &b, &c, &d);
+
+# ifndef have_cmov
+ /* For 32-bit, 99% certainty that we're running on hardware that
+ supports cmov, but we still need to check. In case cmov is not
+ available, we'll use a small forward branch. */
+ have_cmov = ret && (d & bit_CMOV);
+# endif
+
+# ifndef have_movbe
+ /* MOVBE is only available on Intel Atom and Haswell CPUs, so we
+ need to probe for it. */
+ have_movbe = ret && (c & bit_MOVBE);
+# endif
}
#endif
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-23 22:10:39 +0000