Notes from the author:
Here is another one of my speed up patches. Unlike my previous speedups
this one will help more platforms than just X86. It cleans up the Data
Xfer instructions. Since the Data Xfer instructions are the most often
executed instructions it gives a noticable boost in speed. The basic
optimization technique was to eliminate intermediate variables and pass
a pointer to the final destination or original source to the
read_virtual_whatever and the write_virtual_whatever functions.
According to the Intel manuals:
The LOCK prefix can be prepended only to the following instructions
and only to those forms of the instructions where the destination
operand is a memory operand: ADD, ADC, AND, BTC, BTR, BTS, CMPXCHG,
CMPXCH8B, DEC, INC, NEG, NOT, OR, SBB, SUB, XOR, XADD, and XCHG. If
the LOCK prefix is used with one of these instructions and the source
operand is a memory operand, an undefined opcode exception (#UD) will
be generated. An undefined opcode exception will also be generated if
the LOCK prefix is used with any instruction not in the above list.
Checking of the LOCK prefix done in fetchDecode state and not overloads
Bochs's execution.
- it works only on x86 with gcc2.95+
- uses the GCC function atribute "regparm(n)" to declare that certain
functions use the register calling convention
- performance improvement is about 6%
1) fixed the type of "hostPageAddr" and associated typecasts.
2) fixed the type of "pages" and associated typecasts (overloaded variable)
3) patch to cpu.cc to calculate "eipPageBias" correctly in 64 bit mode
1) fixed some errors running 32 bit compat mode. IMPORTANT FIX.
2) added IST processing (uses IST1-IST7 in 64 bit TSS)
3) cosmetic - debugging stuff to console.
a minor optimization. Also in transition from compat mode to 64 bit mode (e.g. interrupt to inner
privelege with mode change), SS may not be properly defined - this avoids other messiness.
* renamed CPU_ID to BX_CPU_ID.
with this new name there is no possibility for name contentions and BX_CPU_ID
definition could be moved out to NEED_CPU_REG_SHORTCUTS block
* returned back `unsigned BX_CPU::which_cpu(void)` function
* added BX_CPU_ID parameter for
BX_INSTR_PHY_READ(a20addr, len);
BX_INSTR_PHY_WRITE(a20addr, len);
now it will be
BX_INSTR_PHY_READ(cpu_id, a20addr, len);
BX_INSTR_PHY_WRITE(cpu_id, a20addr, len);
> CPU_ID is defined as
> #define CPU_ID (BX_CPU_THIS_PTR local_apic.get_id())
> This is not true when the APIC name is changed (true in Linux). Please
> change this to:
> #define CPU_ID (BX_CPU_THIS - BX_CPU(0))
The 64 bit variant of MOVNTI was not decoded. The proper fix for this is to work on
fetchdecode64.cc to call a 64 bit variant of SSE instructions or fail it with a
invalid op. A careful check needs to be done with the AMD manuals to determine if
there are any other SSE instructions that have a special 64 bit decoding.
