Small speedup in boundaryFetch method
This commit is contained in:
Stanislav Shwartsman
parent
0381ff52d3
commit
799403620e
@ -1,5 +1,5 @@
|
||||
/////////////////////////////////////////////////////////////////////////
|
||||
// $Id: cpu.cc,v 1.97 2005-02-05 20:56:44 sshwarts Exp $
|
||||
// $Id: cpu.cc,v 1.98 2005-02-12 14:00:13 sshwarts Exp $
|
||||
/////////////////////////////////////////////////////////////////////////
|
||||
//
|
||||
// Copyright (C) 2001 MandrakeSoft S.A.
|
||||
@ -234,7 +234,7 @@ printf("CPU_LOOP %d\n", bx_guard.special_unwind_stack);
|
||||
#if BX_SUPPORT_ICACHE
|
||||
i = &iStorage; // Leave entry invalid
|
||||
#endif
|
||||
boundaryFetch(i);
|
||||
boundaryFetch(fetchPtr, remainingInPage, i);
|
||||
}
|
||||
else
|
||||
{
|
||||
@ -299,64 +299,64 @@ repeat_loop:
|
||||
if (RCX != 0) {
|
||||
BX_CPU_CALL_METHOD(execute, (i));
|
||||
RCX --;
|
||||
}
|
||||
}
|
||||
if ((i->repUsedValue()==3) && (get_ZF()==0)) goto repeat_done;
|
||||
if ((i->repUsedValue()==2) && (get_ZF()!=0)) goto repeat_done;
|
||||
if (RCX == 0) goto repeat_done;
|
||||
goto repeat_not_done;
|
||||
}
|
||||
}
|
||||
else
|
||||
#endif
|
||||
if (i->as32L()) {
|
||||
if (ECX != 0) {
|
||||
BX_CPU_CALL_METHOD(execute, (i));
|
||||
ECX --;
|
||||
}
|
||||
}
|
||||
if ((i->repUsedValue()==3) && (get_ZF()==0)) goto repeat_done;
|
||||
if ((i->repUsedValue()==2) && (get_ZF()!=0)) goto repeat_done;
|
||||
if (ECX == 0) goto repeat_done;
|
||||
goto repeat_not_done;
|
||||
}
|
||||
}
|
||||
else {
|
||||
if (CX != 0) {
|
||||
BX_CPU_CALL_METHOD(execute, (i));
|
||||
CX --;
|
||||
}
|
||||
}
|
||||
if ((i->repUsedValue()==3) && (get_ZF()==0)) goto repeat_done;
|
||||
if ((i->repUsedValue()==2) && (get_ZF()!=0)) goto repeat_done;
|
||||
if (CX == 0) goto repeat_done;
|
||||
goto repeat_not_done;
|
||||
}
|
||||
}
|
||||
}
|
||||
else { // normal repeat, no concern for ZF
|
||||
#if BX_SUPPORT_X86_64
|
||||
if (i->as64L()) {
|
||||
if (RCX != 0) {
|
||||
BX_CPU_CALL_METHOD(execute, (i));
|
||||
RCX --;
|
||||
}
|
||||
}
|
||||
if (RCX == 0) goto repeat_done;
|
||||
goto repeat_not_done;
|
||||
}
|
||||
}
|
||||
else
|
||||
#endif
|
||||
if (i->as32L()) {
|
||||
if (ECX != 0) {
|
||||
BX_CPU_CALL_METHOD(execute, (i));
|
||||
ECX --;
|
||||
}
|
||||
}
|
||||
if (ECX == 0) goto repeat_done;
|
||||
goto repeat_not_done;
|
||||
}
|
||||
}
|
||||
else { // 16bit addrsize
|
||||
if (CX != 0) {
|
||||
BX_CPU_CALL_METHOD(execute, (i));
|
||||
CX --;
|
||||
}
|
||||
}
|
||||
if (CX == 0) goto repeat_done;
|
||||
goto repeat_not_done;
|
||||
}
|
||||
}
|
||||
}
|
||||
// shouldn't get here from above
|
||||
repeat_not_done:
|
||||
BX_INSTR_REPEAT_ITERATION(BX_CPU_ID);
|
||||
@ -417,8 +417,8 @@ debugger_check:
|
||||
return;
|
||||
default:
|
||||
BX_PANIC(("Weird break point condition"));
|
||||
}
|
||||
}
|
||||
}
|
||||
#if BX_MAGIC_BREAKPOINT
|
||||
// (mch) Magic break point support
|
||||
if (BX_CPU_THIS_PTR magic_break) {
|
||||
@ -426,13 +426,13 @@ debugger_check:
|
||||
BX_DEBUG(("Stopped on MAGIC BREAKPOINT"));
|
||||
BX_CPU_THIS_PTR stop_reason = STOP_MAGIC_BREAK_POINT;
|
||||
return;
|
||||
}
|
||||
}
|
||||
else {
|
||||
BX_CPU_THIS_PTR magic_break = 0;
|
||||
BX_CPU_THIS_PTR stop_reason = STOP_NO_REASON;
|
||||
BX_DEBUG(("Ignoring MAGIC BREAKPOINT"));
|
||||
}
|
||||
}
|
||||
}
|
||||
#endif
|
||||
|
||||
{
|
||||
@ -460,8 +460,7 @@ debugger_check:
|
||||
} // while (1)
|
||||
}
|
||||
|
||||
unsigned
|
||||
BX_CPU_C::handleAsyncEvent(void)
|
||||
unsigned BX_CPU_C::handleAsyncEvent(void)
|
||||
{
|
||||
//
|
||||
// This area is where we process special conditions and events.
|
||||
@ -479,16 +478,16 @@ BX_CPU_C::handleAsyncEvent(void)
|
||||
#else
|
||||
while (1)
|
||||
#endif
|
||||
{
|
||||
{
|
||||
if (BX_CPU_INTR && BX_CPU_THIS_PTR get_IF ()) {
|
||||
break;
|
||||
}
|
||||
}
|
||||
if (BX_CPU_THIS_PTR async_event == 2) {
|
||||
BX_INFO(("decode: reset detected in halt state"));
|
||||
break;
|
||||
}
|
||||
BX_TICK1();
|
||||
}
|
||||
BX_TICK1();
|
||||
}
|
||||
#else /* BX_SMP_PROCESSORS != 1 */
|
||||
// for multiprocessor simulation, even if this CPU is halted we still
|
||||
// must give the others a chance to simulate. If an interrupt has
|
||||
@ -523,7 +522,7 @@ BX_CPU_C::handleAsyncEvent(void)
|
||||
if (BX_CPU_THIS_PTR debug_trap & 0x00008000) {
|
||||
BX_CPU_THIS_PTR dr6 |= BX_CPU_THIS_PTR debug_trap;
|
||||
exception(BX_DB_EXCEPTION, 0, 0); // no error, not interrupt
|
||||
}
|
||||
}
|
||||
|
||||
// Priority 3: External Hardware Interventions
|
||||
// FLUSH
|
||||
@ -536,14 +535,15 @@ BX_CPU_C::handleAsyncEvent(void)
|
||||
// Breakpoints
|
||||
// Debug Trap Exceptions (TF flag set or data/IO breakpoint)
|
||||
if ( BX_CPU_THIS_PTR debug_trap &&
|
||||
!(BX_CPU_THIS_PTR inhibit_mask & BX_INHIBIT_DEBUG) ) {
|
||||
!(BX_CPU_THIS_PTR inhibit_mask & BX_INHIBIT_DEBUG) )
|
||||
{
|
||||
// A trap may be inhibited on this boundary due to an instruction
|
||||
// which loaded SS. If so we clear the inhibit_mask below
|
||||
// and don't execute this code until the next boundary.
|
||||
// Commit debug events to DR6
|
||||
BX_CPU_THIS_PTR dr6 |= BX_CPU_THIS_PTR debug_trap;
|
||||
exception(BX_DB_EXCEPTION, 0, 0); // no error, not interrupt
|
||||
}
|
||||
}
|
||||
|
||||
// Priority 5: External Interrupts
|
||||
// NMI Interrupts
|
||||
@ -554,9 +554,10 @@ BX_CPU_C::handleAsyncEvent(void)
|
||||
// inhibit_mask is cleared below, in which case we will have
|
||||
// an opportunity to check interrupts on the next instruction
|
||||
// boundary.
|
||||
}
|
||||
}
|
||||
else if (BX_CPU_INTR && BX_CPU_THIS_PTR get_IF () &&
|
||||
BX_DBG_ASYNC_INTR) {
|
||||
BX_DBG_ASYNC_INTR)
|
||||
{
|
||||
Bit8u vector;
|
||||
|
||||
// NOTE: similar code in ::take_irq()
|
||||
@ -585,12 +586,12 @@ BX_CPU_C::handleAsyncEvent(void)
|
||||
BX_CPU_THIS_PTR prev_esp = RSP; // commit new RSP
|
||||
BX_CPU_THIS_PTR EXT = 0;
|
||||
BX_CPU_THIS_PTR errorno = 0;
|
||||
}
|
||||
}
|
||||
else if (BX_HRQ && BX_DBG_ASYNC_DMA) {
|
||||
// NOTE: similar code in ::take_dma()
|
||||
// assert Hold Acknowledge (HLDA) and go into a bus hold state
|
||||
DEV_dma_raise_hlda();
|
||||
}
|
||||
}
|
||||
|
||||
// Priority 6: Faults from fetching next instruction
|
||||
// Code breakpoint fault
|
||||
@ -617,18 +618,19 @@ BX_CPU_C::handleAsyncEvent(void)
|
||||
// (handled by rest of the code)
|
||||
|
||||
|
||||
if (BX_CPU_THIS_PTR get_TF ()) {
|
||||
if (BX_CPU_THIS_PTR get_TF ())
|
||||
{
|
||||
// TF is set before execution of next instruction. Schedule
|
||||
// a debug trap (#DB) after execution. After completion of
|
||||
// next instruction, the code above will invoke the trap.
|
||||
BX_CPU_THIS_PTR debug_trap |= 0x00004000; // BS flag in DR6
|
||||
}
|
||||
}
|
||||
|
||||
// Now we can handle things which are synchronous to instruction
|
||||
// execution.
|
||||
if (BX_CPU_THIS_PTR get_RF ()) {
|
||||
BX_CPU_THIS_PTR clear_RF ();
|
||||
}
|
||||
}
|
||||
#if BX_X86_DEBUGGER
|
||||
else {
|
||||
// only bother comparing if any breakpoints enabled
|
||||
@ -638,7 +640,8 @@ BX_CPU_C::handleAsyncEvent(void)
|
||||
BX_CPU_THIS_PTR prev_eip;
|
||||
Bit32u dr6_bits;
|
||||
if ( (dr6_bits = hwdebug_compare(iaddr, 1, BX_HWDebugInstruction,
|
||||
BX_HWDebugInstruction)) ) {
|
||||
BX_HWDebugInstruction)) )
|
||||
{
|
||||
// Add to the list of debug events thus far.
|
||||
BX_CPU_THIS_PTR async_event = 1;
|
||||
BX_CPU_THIS_PTR debug_trap |= dr6_bits;
|
||||
@ -649,10 +652,10 @@ BX_CPU_C::handleAsyncEvent(void)
|
||||
// Commit debug events to DR6
|
||||
BX_CPU_THIS_PTR dr6 = BX_CPU_THIS_PTR debug_trap;
|
||||
exception(BX_DB_EXCEPTION, 0, 0); // no error, not interrupt
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
#endif
|
||||
|
||||
// We have ignored processing of external interrupts and
|
||||
@ -674,8 +677,6 @@ BX_CPU_C::handleAsyncEvent(void)
|
||||
}
|
||||
|
||||
|
||||
|
||||
|
||||
// boundaries of consideration:
|
||||
//
|
||||
// * physical memory boundary: 1024k (1Megabyte) (increments of...)
|
||||
@ -685,9 +686,7 @@ BX_CPU_C::handleAsyncEvent(void)
|
||||
// * segment boundary: any
|
||||
|
||||
|
||||
|
||||
void
|
||||
BX_CPU_C::prefetch(void)
|
||||
void BX_CPU_C::prefetch(void)
|
||||
{
|
||||
// cs:eIP
|
||||
// prefetch QSIZE byte quantity aligned on corresponding boundary
|
||||
@ -760,23 +759,16 @@ BX_CPU_C::prefetch(void)
|
||||
#endif
|
||||
}
|
||||
|
||||
|
||||
void
|
||||
BX_CPU_C::boundaryFetch(bxInstruction_c *i)
|
||||
void BX_CPU_C::boundaryFetch(Bit8u *fetchPtr, unsigned remainingInPage, bxInstruction_c *i)
|
||||
{
|
||||
unsigned j;
|
||||
Bit8u fetchBuffer[16]; // Really only need 15
|
||||
bx_address eipBiased, remainingInPage;
|
||||
Bit8u *fetchPtr;
|
||||
unsigned ret;
|
||||
|
||||
eipBiased = RIP + BX_CPU_THIS_PTR eipPageBias;
|
||||
remainingInPage = (BX_CPU_THIS_PTR eipPageWindowSize - eipBiased);
|
||||
if (remainingInPage >= 15) {
|
||||
BX_INFO(("fetchDecode #GP(0): too many instruction prefixes"));
|
||||
exception(BX_GP_EXCEPTION, 0, 0);
|
||||
}
|
||||
fetchPtr = BX_CPU_THIS_PTR eipFetchPtr + eipBiased;
|
||||
|
||||
// Read all leftover bytes in current page up to boundary.
|
||||
for (j=0; j<remainingInPage; j++) {
|
||||
|
||||
@ -1,5 +1,5 @@
|
||||
/////////////////////////////////////////////////////////////////////////
|
||||
// $Id: cpu.h,v 1.195 2005-02-03 22:08:34 sshwarts Exp $
|
||||
// $Id: cpu.h,v 1.196 2005-02-12 14:00:13 sshwarts Exp $
|
||||
/////////////////////////////////////////////////////////////////////////
|
||||
//
|
||||
// Copyright (C) 2001 MandrakeSoft S.A.
|
||||
@ -2696,7 +2696,7 @@ public: // for now...
|
||||
// now for some ancillary functions...
|
||||
BX_SMF void cpu_loop(Bit32s max_instr_count);
|
||||
BX_SMF unsigned handleAsyncEvent(void);
|
||||
BX_SMF void boundaryFetch(bxInstruction_c *i);
|
||||
BX_SMF void boundaryFetch(Bit8u *fetchPtr, unsigned remainingInPage, bxInstruction_c *i);
|
||||
BX_SMF void branch_near32(Bit32u new_eip) BX_CPP_AttrRegparmN(1);
|
||||
|
||||
BX_SMF void prefetch(void);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user