[Qemu-devel] qemu softmmu inlined lookup sequence

[Xin Tong]

it seems qemu has an inlined sequence to walk the tlb. if that fails,
it does a call out.

    tcg_out_tlb_load(s, addrlo_idx, mem_index, s_bits, args,
                     label_ptr, offsetof(CPUTLBEntry, addr_write));

    /* TLB Hit.  */
    tcg_out_qemu_st_direct(s, data_reg, data_reg2,
                           tcg_target_call_iarg_regs[0], 0, opc);

    /* jmp label2 */
    tcg_out8(s, OPC_JMP_short);
    label_ptr[2] = s->code_ptr;
    s->code_ptr++;

   /* TLB Miss. */
   ...
   tcg_out_calli(s, (tcg_target_long)qemu_st_helpers[s_bits]);


what does the inline sequence look like ? what kind of things (other
than refill tlb) performed in callout but not the inlined sequence ?

Thanks

Xin