tcg-i386: Tidy lea.
Implement full modrm+sib addressing mode processing. Use that in qemu_ld/st to output the LEA. Signed-off-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
This commit is contained in:
parent
b3e66df71a
commit
34a6d0b7fc
@ -174,6 +174,7 @@ static inline int tcg_target_const_match(tcg_target_long val,
|
||||
#define OPC_JCC_short (0x70) /* ... plus condition code */
|
||||
#define OPC_JMP_long (0xe9)
|
||||
#define OPC_JMP_short (0xeb)
|
||||
#define OPC_LEA (0x8d)
|
||||
#define OPC_MOVB_EvGv (0x88) /* stores, more or less */
|
||||
#define OPC_MOVL_EvGv (0x89) /* stores, more or less */
|
||||
#define OPC_MOVL_GvEv (0x8b) /* loads, more or less */
|
||||
@ -272,40 +273,70 @@ static inline void tcg_out_modrm(TCGContext *s, int opc, int r, int rm)
|
||||
tcg_out8(s, 0xc0 | (r << 3) | rm);
|
||||
}
|
||||
|
||||
/* rm == -1 means no register index */
|
||||
static inline void tcg_out_modrm_offset(TCGContext *s, int opc, int r, int rm,
|
||||
int32_t offset)
|
||||
/* Output an opcode with a full "rm + (index<<shift) + offset" address mode.
|
||||
We handle either RM and INDEX missing with a -1 value. */
|
||||
|
||||
static void tcg_out_modrm_sib_offset(TCGContext *s, int opc, int r, int rm,
|
||||
int index, int shift, int32_t offset)
|
||||
{
|
||||
tcg_out_opc(s, opc);
|
||||
if (rm == -1) {
|
||||
tcg_out8(s, 0x05 | (r << 3));
|
||||
int mod, len;
|
||||
|
||||
if (index == -1 && rm == -1) {
|
||||
/* Absolute address. */
|
||||
tcg_out_opc(s, opc);
|
||||
tcg_out8(s, (r << 3) | 5);
|
||||
tcg_out32(s, offset);
|
||||
return;
|
||||
}
|
||||
|
||||
tcg_out_opc(s, opc);
|
||||
|
||||
/* Find the length of the immediate addend. Note that the encoding
|
||||
that would be used for (%ebp) indicates absolute addressing. */
|
||||
if (rm == -1) {
|
||||
mod = 0, len = 4, rm = 5;
|
||||
} else if (offset == 0 && rm != TCG_REG_EBP) {
|
||||
if (rm == TCG_REG_ESP) {
|
||||
tcg_out8(s, 0x04 | (r << 3));
|
||||
tcg_out8(s, 0x24);
|
||||
} else {
|
||||
tcg_out8(s, 0x00 | (r << 3) | rm);
|
||||
}
|
||||
} else if ((int8_t)offset == offset) {
|
||||
if (rm == TCG_REG_ESP) {
|
||||
tcg_out8(s, 0x44 | (r << 3));
|
||||
tcg_out8(s, 0x24);
|
||||
} else {
|
||||
tcg_out8(s, 0x40 | (r << 3) | rm);
|
||||
}
|
||||
tcg_out8(s, offset);
|
||||
mod = 0, len = 0;
|
||||
} else if (offset == (int8_t)offset) {
|
||||
mod = 0x40, len = 1;
|
||||
} else {
|
||||
if (rm == TCG_REG_ESP) {
|
||||
tcg_out8(s, 0x84 | (r << 3));
|
||||
tcg_out8(s, 0x24);
|
||||
mod = 0x80, len = 4;
|
||||
}
|
||||
|
||||
/* Use a single byte MODRM format if possible. Note that the encoding
|
||||
that would be used for %esp is the escape to the two byte form. */
|
||||
if (index == -1 && rm != TCG_REG_ESP) {
|
||||
/* Single byte MODRM format. */
|
||||
tcg_out8(s, mod | (r << 3) | rm);
|
||||
} else {
|
||||
/* Two byte MODRM+SIB format. */
|
||||
|
||||
/* Note that the encoding that would place %esp into the index
|
||||
field indicates no index register. */
|
||||
if (index == -1) {
|
||||
index = 4;
|
||||
} else {
|
||||
tcg_out8(s, 0x80 | (r << 3) | rm);
|
||||
assert(index != TCG_REG_ESP);
|
||||
}
|
||||
|
||||
tcg_out8(s, mod | (r << 3) | 4);
|
||||
tcg_out8(s, (shift << 6) | (index << 3) | rm);
|
||||
}
|
||||
|
||||
if (len == 1) {
|
||||
tcg_out8(s, offset);
|
||||
} else if (len == 4) {
|
||||
tcg_out32(s, offset);
|
||||
}
|
||||
}
|
||||
|
||||
/* rm == -1 means no register index */
|
||||
static inline void tcg_out_modrm_offset(TCGContext *s, int opc, int r, int rm,
|
||||
int32_t offset)
|
||||
{
|
||||
tcg_out_modrm_sib_offset(s, opc, r, rm, -1, 0, offset);
|
||||
}
|
||||
|
||||
/* Generate dest op= src. Uses the same ARITH_* codes as tgen_arithi. */
|
||||
static inline void tgen_arithr(TCGContext *s, int subop, int dest, int src)
|
||||
{
|
||||
@ -710,10 +741,9 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args,
|
||||
tgen_arithi(s, ARITH_AND, r0, TARGET_PAGE_MASK | ((1 << s_bits) - 1), 0);
|
||||
tgen_arithi(s, ARITH_AND, r1, (CPU_TLB_SIZE - 1) << CPU_TLB_ENTRY_BITS, 0);
|
||||
|
||||
tcg_out_opc(s, 0x8d); /* lea offset(r1, %ebp), r1 */
|
||||
tcg_out8(s, 0x80 | (r1 << 3) | 0x04);
|
||||
tcg_out8(s, (5 << 3) | r1);
|
||||
tcg_out32(s, offsetof(CPUState, tlb_table[mem_index][0].addr_read));
|
||||
tcg_out_modrm_sib_offset(s, OPC_LEA, r1, TCG_AREG0, r1, 0,
|
||||
offsetof(CPUState,
|
||||
tlb_table[mem_index][0].addr_read));
|
||||
|
||||
/* cmp 0(r1), r0 */
|
||||
tcg_out_modrm_offset(s, OPC_CMP_GvEv, r0, r1, 0);
|
||||
@ -903,10 +933,9 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args,
|
||||
tgen_arithi(s, ARITH_AND, r0, TARGET_PAGE_MASK | ((1 << s_bits) - 1), 0);
|
||||
tgen_arithi(s, ARITH_AND, r1, (CPU_TLB_SIZE - 1) << CPU_TLB_ENTRY_BITS, 0);
|
||||
|
||||
tcg_out_opc(s, 0x8d); /* lea offset(r1, %ebp), r1 */
|
||||
tcg_out8(s, 0x80 | (r1 << 3) | 0x04);
|
||||
tcg_out8(s, (5 << 3) | r1);
|
||||
tcg_out32(s, offsetof(CPUState, tlb_table[mem_index][0].addr_write));
|
||||
tcg_out_modrm_sib_offset(s, OPC_LEA, r1, TCG_AREG0, r1, 0,
|
||||
offsetof(CPUState,
|
||||
tlb_table[mem_index][0].addr_write));
|
||||
|
||||
/* cmp 0(r1), r0 */
|
||||
tcg_out_modrm_offset(s, OPC_CMP_GvEv, r0, r1, 0);
|
||||
|
Loading…
Reference in New Issue
Block a user