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- define macros to work around VC++ brain-dead-ness about converting between

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unsigned 64-bit integer and 64-bit double precision floating point.  It
  knows how to convert Bit64s to double, but it refuses to convert Bit64u
  to double.  The macros: F2I converts from floating point to integer, and
  I2F converts the other way, using Bit64s as a transition step.
    F2I:  double -> Bit64s -> Bit64u
	I2F:  Bit64u -> Bit64s -> double
This commit is contained in:
Bryce Denney 2002-12-05 17:43:00 +00:00
parent 833a03ac15
commit e9b135a5c6
1 changed files with 12 additions and 5 deletions
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17
bochs/iodev/pit_wrap.cc
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@ -1,5 +1,5 @@
/////////////////////////////////////////////////////////////////////////
// $Id: pit_wrap.cc,v 1.38 2002-12-04 19:51:51 yakovlev Exp $
// $Id: pit_wrap.cc,v 1.39 2002-12-05 17:43:00 bdenney Exp $
/////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2002 MandrakeSoft S.A.
@ -73,6 +73,13 @@
#define TICKS_PER_SECOND (1193181)
// define a macro to convert floating point numbers into 64-bit integers.
// In MSVC++ you can convert a 64-bit float into a 64-bit signed integer,
// but it will not convert a 64-bit float into a 64-bit unsigned integer.
// This macro works around that.
#define F2I(x) ((Bit64u)(Bit64s) (x))
#define I2F(x) ((double)(Bit64s) (x))
//CONFIGURATION #defines:
@ -141,7 +148,7 @@ bx_pit_c bx_pit;
#define USEC_ALPHA_B ((double)(((double)1)-USEC_ALPHA))
#define USEC_ALPHA2 ((double)(.5))
#define USEC_ALPHA2_B ((double)(((double)1)-USEC_ALPHA2))
#define ALPHA_LOWER(old,new) ((Bit64u)((old<new)?((USEC_ALPHA*((double)(old)))+(USEC_ALPHA_B*((double)new))):((USEC_ALPHA2*((double)old))+(USEC_ALPHA2_B*((double)new)))))
#define ALPHA_LOWER(old,new) ((Bit64u)((old<new)?((USEC_ALPHA*(I2F(old)))+(USEC_ALPHA_B*(I2F(new)))):((USEC_ALPHA2*(I2F(old)))+(USEC_ALPHA2_B*(I2F(new))))))
//PIT tick to usec conversion functions:
@ -506,10 +513,10 @@ bx_pit_c::periodic( Bit32u usec_delta )
// probably only an issue on startup, but it solves some problems.
ticks_delta = 0;
}
if(ticks_delta > REAL_USEC_TO_TICKS((Bit64u)(MAX_MULT * real_time_delta))) {
if(ticks_delta > REAL_USEC_TO_TICKS(F2I(MAX_MULT * I2F(real_time_delta)))) {
//This keeps us from going too fast in relation to real time.
ticks_delta = REAL_USEC_TO_TICKS((Bit64u)(MAX_MULT * real_time_delta));
BX_PIT_THIS s.ticks_per_second = (Bit64u)(MAX_MULT * TICKS_PER_SECOND);
ticks_delta = REAL_USEC_TO_TICKS(F2I (MAX_MULT * I2F(real_time_delta)));
BX_PIT_THIS s.ticks_per_second = F2I(MAX_MULT * I2F(TICKS_PER_SECOND));
}
if(ticks_delta > em_time_delta * TICKS_PER_SECOND / MIN_USEC_PER_SECOND) {
//This keeps us from having too few instructions between ticks.