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qemu
提交 4810d96f 编写于 作者: R Richard Henderson
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tcg/i386: Assume 32-bit values are zero-extended 

We now have an invariant that all TCG_TYPE_I32 values are
zero-extended, which means that we do not need to extend
them again during qemu_ld/st, either explicitly via a separate
tcg_out_ext32u or implicitly via P_ADDR32.
Reviewed-by: NEmilio G. Cota <cota@braap.org>
Signed-off-by: NRichard Henderson <richard.henderson@linaro.org>
上级 75478279
隐藏空白更改
内联 并排
Showing with 40 addition and 63 deletion
tcg/i386/tcg-target.inc.c
浏览文件 @ 4810d96f
......@@ -309,13 +309,11 @@ static inline int tcg_target_const_match(tcg_target_long val, TCGType type,
#define P_EXT38 0x200 /* 0x0f 0x38 opcode prefix */
#define P_DATA16 0x400 /* 0x66 opcode prefix */
#if TCG_TARGET_REG_BITS == 64
# define P_ADDR32 0x800 /* 0x67 opcode prefix */
# define P_REXW 0x1000 /* Set REX.W = 1 */
# define P_REXB_R 0x2000 /* REG field as byte register */
# define P_REXB_RM 0x4000 /* R/M field as byte register */
# define P_GS 0x8000 /* gs segment override */
#else
# define P_ADDR32 0
# define P_REXW 0
# define P_REXB_R 0
# define P_REXB_RM 0
......@@ -528,9 +526,6 @@ static void tcg_out_opc(TCGContext *s, int opc, int r, int rm, int x)
tcg_debug_assert((opc & P_REXW) == 0);
tcg_out8(s, 0x66);
}
if (opc & P_ADDR32) {
tcg_out8(s, 0x67);
}
if (opc & P_SIMDF3) {
tcg_out8(s, 0xf3);
} else if (opc & P_SIMDF2) {
......@@ -1659,11 +1654,7 @@ static inline void tcg_out_tlb_load(TCGContext *s, TCGReg addrlo, TCGReg addrhi,
tcg_out_modrm_offset(s, OPC_CMP_GvEv + trexw, r1, r0, 0);
/* Prepare for both the fast path add of the tlb addend, and the slow
path function argument setup. There are two cases worth note:
For 32-bit guest and x86_64 host, MOVL zero-extends the guest address
before the fastpath ADDQ below. For 64-bit guest and x32 host, MOVQ
copies the entire guest address for the slow path, while truncation
for the 32-bit host happens with the fastpath ADDL below. */
path function argument setup. */
tcg_out_mov(s, ttype, r1, addrlo);
/* jne slow_path */
......@@ -2022,41 +2013,31 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args, bool is64)
#else
{
int32_t offset = guest_base;
TCGReg base = addrlo;
int index = -1;
int seg = 0;
/* For a 32-bit guest, the high 32 bits may contain garbage.
We can do this with the ADDR32 prefix if we're not using
a guest base, or when using segmentation. Otherwise we
need to zero-extend manually. */
/*
* Recall we store 32-bit values zero-extended. No need for
* further manual extension or an addr32 (0x67) prefix.
*/
if (guest_base == 0 || guest_base_flags) {
seg = guest_base_flags;
offset = 0;
if (TCG_TARGET_REG_BITS > TARGET_LONG_BITS) {
seg |= P_ADDR32;
}
} else if (TCG_TARGET_REG_BITS == 64) {
if (TARGET_LONG_BITS == 32) {
tcg_out_ext32u(s, TCG_REG_L0, base);
base = TCG_REG_L0;
}
if (offset != guest_base) {
tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_L1, guest_base);
index = TCG_REG_L1;
offset = 0;
}
} else if (TCG_TARGET_REG_BITS == 64 && offset != guest_base) {
tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_L1, guest_base);
index = TCG_REG_L1;
offset = 0;
}
tcg_out_qemu_ld_direct(s, datalo, datahi,
base, index, offset, seg, is64, opc);
addrlo, index, offset, seg, is64, opc);
}
#endif
}
static void tcg_out_qemu_st_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
TCGReg base, intptr_t ofs, int seg,
TCGMemOp memop)
TCGReg base, int index, intptr_t ofs,
int seg, TCGMemOp memop)
{
/* ??? Ideally we wouldn't need a scratch register. For user-only,
we could perform the bswap twice to restore the original value
......@@ -2080,8 +2061,8 @@ static void tcg_out_qemu_st_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
tcg_out_mov(s, TCG_TYPE_I32, scratch, datalo);
datalo = scratch;
}
tcg_out_modrm_offset(s, OPC_MOVB_EvGv + P_REXB_R + seg,
datalo, base, ofs);
tcg_out_modrm_sib_offset(s, OPC_MOVB_EvGv + P_REXB_R + seg,
datalo, base, index, 0, ofs);
break;
case MO_16:
if (bswap) {
......@@ -2089,7 +2070,8 @@ 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, movop + P_DATA16 + seg, datalo, base, ofs);
tcg_out_modrm_sib_offset(s, movop + P_DATA16 + seg, datalo,
base, index, 0, ofs);
break;
case MO_32:
if (bswap) {
......@@ -2097,7 +2079,7 @@ 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, movop + seg, datalo, base, ofs);
tcg_out_modrm_sib_offset(s, movop + seg, datalo, base, index, 0, ofs);
break;
case MO_64:
if (TCG_TARGET_REG_BITS == 64) {
......@@ -2106,22 +2088,27 @@ 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, movop + P_REXW + seg, datalo, base, ofs);
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_offset(s, OPC_MOVL_EvGv + seg, scratch, base, ofs);
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_offset(s, OPC_MOVL_EvGv + seg, scratch, base, ofs+4);
tcg_out_modrm_sib_offset(s, OPC_MOVL_EvGv + seg, scratch,
base, index, 0, ofs + 4);
} else {
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);
tcg_out_modrm_sib_offset(s, movop + seg, datalo,
base, index, 0, ofs);
tcg_out_modrm_sib_offset(s, movop + seg, datahi,
base, index, 0, ofs + 4);
}
break;
default:
......@@ -2154,7 +2141,7 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, bool is64)
label_ptr, offsetof(CPUTLBEntry, addr_write));
/* TLB Hit. */
tcg_out_qemu_st_direct(s, datalo, datahi, TCG_REG_L1, 0, 0, opc);
tcg_out_qemu_st_direct(s, datalo, datahi, TCG_REG_L1, -1, 0, 0, opc);
/* Record the current context of a store into ldst label */
add_qemu_ldst_label(s, false, is64, oi, datalo, datahi, addrlo, addrhi,
......@@ -2162,35 +2149,25 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, bool is64)
#else
{
int32_t offset = guest_base;
TCGReg base = addrlo;
int index = -1;
int seg = 0;
/* See comment in tcg_out_qemu_ld re zero-extension of addrlo. */
/*
* Recall we store 32-bit values zero-extended. No need for
* further manual extension or an addr32 (0x67) prefix.
*/
if (guest_base == 0 || guest_base_flags) {
seg = guest_base_flags;
offset = 0;
if (TCG_TARGET_REG_BITS > TARGET_LONG_BITS) {
seg |= P_ADDR32;
}
} else if (TCG_TARGET_REG_BITS == 64) {
/* ??? Note that we can't use the same SIB addressing scheme
as for loads, since we require L0 free for bswap. */
if (offset != guest_base) {
if (TARGET_LONG_BITS == 32) {
tcg_out_ext32u(s, TCG_REG_L0, base);
base = TCG_REG_L0;
}
tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_L1, guest_base);
tgen_arithr(s, ARITH_ADD + P_REXW, TCG_REG_L1, base);
base = TCG_REG_L1;
offset = 0;
} else if (TARGET_LONG_BITS == 32) {
tcg_out_ext32u(s, TCG_REG_L1, base);
base = TCG_REG_L1;
}
} else if (TCG_TARGET_REG_BITS == 64 && offset != guest_base) {
/* ??? Note that we require L0 free for bswap. */
tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_L1, guest_base);
index = TCG_REG_L1;
offset = 0;
}
tcg_out_qemu_st_direct(s, datalo, datahi, base, offset, seg, opc);
tcg_out_qemu_st_direct(s, datalo, datahi,
addrlo, index, offset, seg, opc);
}
#endif
}
......
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