On 07/30/2012 05:38 PM, Gleb Natapov wrote:
> Optimize "rep ins" by allowing emulator to write back more than one
> datum at a time. Introduce new operand type OP_MEM_STR which tells
> writeback() that dst contains pointer to an array that should be written
> back as opposite to just one data element.
>
> }
>
> - memcpy(dest, rc->data + rc->pos, size);
> - rc->pos += size;
> + if (ctxt->rep_prefix && !(ctxt->eflags & EFLG_DF)) {
> + ctxt->dst.data = rc->data + rc->pos;
> + ctxt->dst.type = OP_MEM_STR;
> + ctxt->dst.count = (rc->end - rc->pos) / size;
> + rc->pos = rc->end;
Should take into account the segment limit.
> + } else {
> + memcpy(dest, rc->data + rc->pos, size);
> + rc->pos += size;
> + }
> return 1;
> }
>
> @@ -1500,6 +1507,14 @@ static int writeback(struct x86_emulate_ctxt *ctxt)
> if (rc != X86EMUL_CONTINUE)
> return rc;
> break;
> + case OP_MEM_STR:
> + rc = segmented_write(ctxt,
> + ctxt->dst.addr.mem,
> + ctxt->dst.data,
> + ctxt->dst.bytes * ctxt->dst.count);
> + if (rc != X86EMUL_CONTINUE)
> + return rc;
> + break;
> case OP_XMM:
> write_sse_reg(ctxt, &ctxt->dst.vec_val, ctxt->dst.addr.xmm);
> break;
> @@ -2732,7 +2747,7 @@ int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
> static void string_addr_inc(struct x86_emulate_ctxt *ctxt, int reg,
> struct operand *op)
> {
> - int df = (ctxt->eflags & EFLG_DF) ? -1 : 1;
> + int df = (ctxt->eflags & EFLG_DF) ? -op->count : op->count;
>
> register_address_increment(ctxt, &ctxt->regs[reg], df * op->bytes);
> op->addr.mem.ea = register_address(ctxt, ctxt->regs[reg]);
> @@ -3672,7 +3687,7 @@ static struct opcode opcode_table[256] = {
> I(DstReg | SrcMem | ModRM | Src2Imm, em_imul_3op),
> I(SrcImmByte | Mov | Stack, em_push),
> I(DstReg | SrcMem | ModRM | Src2ImmByte, em_imul_3op),
> - I2bvIP(DstDI | SrcDX | Mov | String, em_in, ins, check_perm_in), /*
> insb, insw/insd */
> + I2bvIP(DstDI | SrcDX | Mov | String | Unaligned, em_in, ins,
> check_perm_in), /* insb, insw/insd */
Eww.
> I2bvIP(SrcSI | DstDX | String, em_out, outs, check_perm_out), /* outsb,
> outsw/outsd */
> /* 0x70 - 0x7F */
> X16(D(SrcImmByte)),
> @@ -3930,6 +3945,7 @@ static int decode_operand(struct x86_emulate_ctxt
> *ctxt, struct operand *op,
> register_address(ctxt, ctxt->regs[VCPU_REGS_RDI]);
> op->addr.mem.seg = VCPU_SREG_ES;
> op->val = 0;
> + op->count = 1;
> break;
> case OpDX:
> op->type = OP_REG;
> @@ -3973,6 +3989,7 @@ static int decode_operand(struct x86_emulate_ctxt
> *ctxt, struct operand *op,
> register_address(ctxt, ctxt->regs[VCPU_REGS_RSI]);
> op->addr.mem.seg = seg_override(ctxt);
> op->val = 0;
> + op->count = 1;
> break;
> case OpImmFAddr:
> op->type = OP_IMM;
> @@ -4513,8 +4530,14 @@ writeback:
> string_addr_inc(ctxt, VCPU_REGS_RDI, &ctxt->dst);
>
> if (ctxt->rep_prefix && (ctxt->d & String)) {
> + unsigned int count;
> struct read_cache *r = &ctxt->io_read;
> - register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RCX],
> -1);
> + if ((ctxt->d & SrcMask) == SrcSI)
> + count = ctxt->src.count;
> + else
> + count = ctxt->dst.count;
Does this work correctly for 'rep movs' and friends?
--
error compiling committee.c: too many arguments to function
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