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optimized some float/int conversions, added -fomit-frame-pointer flag

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This commit is contained in:
ekeeke31 2009-01-28 16:43:15 +00:00
parent b9cab7c7c4
commit 43fd560e55
10 changed files with 101 additions and 117 deletions
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2
Makefile.gc
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@ -26,7 +26,7 @@ INCLUDES := source source/m68k source/z80 source/sound source/sound/SRC source/n
# options for code generation # options for code generation
#--------------------------------------------------------------------------------- #---------------------------------------------------------------------------------
CFLAGS = -O3 -Wall $(MACHDEP) $(INCLUDE) -DWORDS_BIGENDIAN -DNGC="1" -DHW_DOL CFLAGS = -O3 -fomit-frame-pointer -Wall $(MACHDEP) $(INCLUDE) -DWORDS_BIGENDIAN -DNGC="1" -DHW_DOL
CXXFLAGS = $(CFLAGS) CXXFLAGS = $(CFLAGS)
LDFLAGS = $(MACHDEP) -Wl,-Map,$(notdir $@).map LDFLAGS = $(MACHDEP) -Wl,-Map,$(notdir $@).map

2
Makefile.wii
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@ -26,7 +26,7 @@ INCLUDES := source source/m68k source/z80 source/sound source/sound/SRC source/n
# options for code generation # options for code generation
#--------------------------------------------------------------------------------- #---------------------------------------------------------------------------------
CFLAGS = -O3 -mrvl -Wall $(MACHDEP) -Wno-strict-aliasing $(INCLUDE) -DWORDS_BIGENDIAN -DNGC="1" -DHW_RVL CFLAGS = -O3 -fomit-frame-pointer -mrvl -Wall $(MACHDEP) -Wno-strict-aliasing $(INCLUDE) -DWORDS_BIGENDIAN -DNGC="1" -DHW_RVL
CXXFLAGS = $(CFLAGS) CXXFLAGS = $(CFLAGS)
LDFLAGS = $(MACHDEP) -Wl,-Map,$(notdir $@).map LDFLAGS = $(MACHDEP) -Wl,-Map,$(notdir $@).map

4
source/ngc/config.h
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@ -31,8 +31,8 @@
typedef struct typedef struct
{ {
char version[15]; char version[15];
double psg_preamp; int32 psg_preamp;
double fm_preamp; int32 fm_preamp;
uint8 boost; uint8 boost;
uint8 filter; uint8 filter;
uint8 hq_fm; uint8 hq_fm;

8
source/sound/fm.c
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@ -1804,8 +1804,16 @@ void YM2612UpdateOne(int **buffer, int length)
Limit(rt,MAXOUT,MINOUT); Limit(rt,MAXOUT,MINOUT);
/* buffering */ /* buffering */
if (src_buffer)
{
src_buffer[i*2] = (float) lt / (8.0 * 0x10000000);
src_buffer[i*2 + 1] = (float) rt / (8.0 * 0x10000000);
}
else
{
bufL[i] = lt; bufL[i] = lt;
bufR[i] = rt; bufR[i] = rt;
}
/* timer A control */ /* timer A control */
INTERNAL_TIMER_A(); INTERNAL_TIMER_A();

2
source/sound/sn76489.c
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@ -48,7 +48,7 @@ static SN76489_Context SN76489[MAX_SN76489];
void SN76489_Init(int which, int PSGClockValue, int SamplingRate) void SN76489_Init(int which, int PSGClockValue, int SamplingRate)
{ {
SN76489_Context *p = &SN76489[which]; SN76489_Context *p = &SN76489[which];
p->dClock=(float)PSGClockValue/16/SamplingRate; p->dClock=(float)(PSGClockValue)/16.0/(float)SamplingRate;
SN76489_Config(which, MUTE_ALLON, VOL_FULL, FB_SEGAVDP, SRW_SEGAVDP, 1); SN76489_Config(which, MUTE_ALLON, VOL_FULL, FB_SEGAVDP, SRW_SEGAVDP, 1);
SN76489_Reset(which); SN76489_Reset(which);
} }

87
source/sound/sound.c
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@ -22,7 +22,6 @@
****************************************************************************************/ ****************************************************************************************/
#include "shared.h" #include "shared.h"
#include "samplerate.h"
#define CLOCK_NTSC 53693175 #define CLOCK_NTSC 53693175
#define CLOCK_PAL 53203424 #define CLOCK_PAL 53203424
@ -34,13 +33,10 @@ void (*_YM2612_Update)(int **buf, int length);
int (*_YM2612_Reset)(void); int (*_YM2612_Reset)(void);
/* cycle-accurate samples */ /* cycle-accurate samples */
static double m68cycles_per_sample[2]; static int m68cycles_per_sample[2];
static double z80cycles_per_sample[2];
/* libsamplerate buffers (max. is 488 cycles per line x 313 lines / 144) */ /* pointer to current SRC buffer */
static SRC_DATA src_data; float *src_buffer;
static float src_in[1061*2];
static int src_buffer[2][1061];
/* YM2612 register arrays */ /* YM2612 register arrays */
int fm_reg[2][0x100]; int fm_reg[2][0x100];
@ -48,14 +44,14 @@ int fm_reg[2][0x100];
/* return the number of samples that should have been rendered so far */ /* return the number of samples that should have been rendered so far */
static inline uint32 fm_sample_cnt(uint8 is_z80) static inline uint32 fm_sample_cnt(uint8 is_z80)
{ {
if (is_z80) return (uint32) ((double)(count_z80 + current_z80 - z80_ICount) / z80cycles_per_sample[0]); if (is_z80) return ((count_z80 + current_z80 - z80_ICount) * 15) / (7 * m68cycles_per_sample[0]);
else return (uint32) ((double) count_m68k / m68cycles_per_sample[0]); else return count_m68k / m68cycles_per_sample[0];
} }
static inline uint32 psg_sample_cnt(uint8 is_z80) static inline uint32 psg_sample_cnt(uint8 is_z80)
{ {
if (is_z80) return (uint32) ((double)(count_z80 + current_z80 - z80_ICount) / z80cycles_per_sample[1]); if (is_z80) return ((count_z80 + current_z80 - z80_ICount) * 15) / (7 * m68cycles_per_sample[1]);
else return (uint32) ((double) count_m68k / m68cycles_per_sample[1]); else return count_m68k / m68cycles_per_sample[1];
} }
/* update FM samples */ /* update FM samples */
@ -64,16 +60,12 @@ static inline void fm_update()
if(snd.fm.curStage - snd.fm.lastStage > 0) if(snd.fm.curStage - snd.fm.lastStage > 0)
{ {
int *tempBuffer[2]; int *tempBuffer[2];
if (config.hq_fm && !config.fm_core)
{
tempBuffer[0] = src_buffer[0] + snd.fm.lastStage;
tempBuffer[1] = src_buffer[1] + snd.fm.lastStage;
}
else
{
tempBuffer[0] = snd.fm.buffer[0] + snd.fm.lastStage; tempBuffer[0] = snd.fm.buffer[0] + snd.fm.lastStage;
tempBuffer[1] = snd.fm.buffer[1] + snd.fm.lastStage; tempBuffer[1] = snd.fm.buffer[1] + snd.fm.lastStage;
if (src_buffer)
{
src_buffer = src_data.data_in + (snd.fm.lastStage * 2);
} }
_YM2612_Update(tempBuffer, snd.fm.curStage - snd.fm.lastStage); _YM2612_Update(tempBuffer, snd.fm.curStage - snd.fm.lastStage);
@ -97,28 +89,20 @@ void sound_init(int rate)
double vclk = (vdp_pal ? (double)CLOCK_PAL : (double)CLOCK_NTSC) / 7.0; /* 68000 and YM2612 clock */ double vclk = (vdp_pal ? (double)CLOCK_PAL : (double)CLOCK_NTSC) / 7.0; /* 68000 and YM2612 clock */
double zclk = (vdp_pal ? (double)CLOCK_PAL : (double)CLOCK_NTSC) / 15.0; /* Z80 and SN76489 clock */ double zclk = (vdp_pal ? (double)CLOCK_PAL : (double)CLOCK_NTSC) / 15.0; /* Z80 and SN76489 clock */
/* cycle-accurate FM samples */ /* cycle-accurate samples */
if (config.hq_fm && !config.fm_core) m68cycles_per_sample[0] = (m68cycles_per_line * lines_per_frame * vdp_rate) / rate;
{ m68cycles_per_sample[1] = (m68cycles_per_line * lines_per_frame * vdp_rate) / rate;
m68cycles_per_sample[0] = 144.0;
z80cycles_per_sample[0] = (144.0 * 7.0) / 15.0;
/* initialize samplerate converter data */ /* YM2612 is emulated at the original frequency */
src_data.data_in = src_in; src_buffer = 0;
src_data.data_out = snd.fm.src_out; if (src_data.data_in)
src_data.input_frames = (int)(((double)m68cycles_per_line * (double)lines_per_frame / 144.0) + 0.5);
src_data.output_frames = rate / vdp_rate;
src_data.src_ratio = (double)src_data.output_frames / (double)src_data.input_frames;
}
else
{ {
m68cycles_per_sample[0] = ((double)m68cycles_per_line * (double)lines_per_frame) / (double) (rate / vdp_rate); /* YM2612 original frequency is VCLK/144 */
z80cycles_per_sample[0] = ((double)z80cycles_per_line * (double)lines_per_frame) / (double) (rate / vdp_rate); m68cycles_per_sample[0] = 144;
}
/* cycle-accurate PSG samples */ /* Initialize SRC buffer */
m68cycles_per_sample[1] = ((double)m68cycles_per_line * (double)lines_per_frame) / (double) (rate / vdp_rate); src_buffer = src_data.data_in;
z80cycles_per_sample[1] = ((double)z80cycles_per_line * (double)lines_per_frame) / (double) (rate / vdp_rate); }
/* initialize sound chips */ /* initialize sound chips */
SN76489_Init(0, (int)zclk, rate); SN76489_Init(0, (int)zclk, rate);
@ -145,7 +129,7 @@ void sound_init(int rate)
void sound_update(void) void sound_update(void)
{ {
/* finalize sound buffers */ /* finalize sound buffers */
snd.fm.curStage = (config.hq_fm && !config.fm_core) ? src_data.input_frames : snd.buffer_size; snd.fm.curStage = (src_data.data_in) ? src_data.input_frames : snd.buffer_size;
snd.psg.curStage = snd.buffer_size; snd.psg.curStage = snd.buffer_size;
/* update last samples (if needed) */ /* update last samples (if needed) */
@ -153,43 +137,32 @@ void sound_update(void)
psg_update(); psg_update();
/* Resampling */ /* Resampling */
if (config.hq_fm && !config.fm_core) if (src_data.data_in)
{ {
double scaled_value ;
int len = src_data.input_frames;
/* this is basically libsamplerate "src_int_to_float_array" function, adapted to interlace samples */
while (len)
{
len -- ;
src_in[len*2] = (float) (src_buffer[0] [len] / (8.0 * 0x10000000));
src_in[len*2 + 1] = (float) (src_buffer[1] [len] / (8.0 * 0x10000000));
}
/* samplerate conversion */ /* samplerate conversion */
src_simple (&src_data, (config.hq_fm&1) ? SRC_LINEAR : SRC_SINC_FASTEST, 2); src_simple (&src_data, (config.hq_fm&1) ? SRC_LINEAR : SRC_SINC_FASTEST, 2);
/* this is basically libsamplerate "src_float_to_int_array" function, adapted to interlace samples */ /* this is basically libsamplerate "src_float_to_int_array" function, adapted to interlace samples */
len = snd.buffer_size; double scaled_value;
int len = snd.buffer_size;
while (len) while (len)
{ {
len -- ; len -- ;
scaled_value = src_data.data_out[len*2] * (8.0 * 0x10000000);
scaled_value = snd.fm.src_out[len*2] * (8.0 * 0x10000000);
if (scaled_value >= (1.0 * 0x7FFFFFFF)) if (scaled_value >= (1.0 * 0x7FFFFFFF))
snd.fm.buffer[0][len] = 0x7fffffff; snd.fm.buffer[0][len] = 0x7fffffff;
else if (scaled_value <= (-8.0 * 0x10000000)) else if (scaled_value <= (-8.0 * 0x10000000))
snd.fm.buffer[0][len] = -1 - 0x7fffffff; snd.fm.buffer[0][len] = -1 - 0x7fffffff;
else else
snd.fm.buffer[0][len] = (long)scaled_value; snd.fm.buffer[0][len] = lrint(scaled_value);
scaled_value = snd.fm.src_out[len*2+1] * (8.0 * 0x10000000); scaled_value = src_data.data_out[len*2+1] * (8.0 * 0x10000000);
if (scaled_value >= (1.0 * 0x7FFFFFFF)) if (scaled_value >= (1.0 * 0x7FFFFFFF))
snd.fm.buffer[1][len] = 0x7fffffff; snd.fm.buffer[1][len] = 0x7fffffff;
else if (scaled_value <= (-8.0 * 0x10000000)) else if (scaled_value <= (-8.0 * 0x10000000))
snd.fm.buffer[1][len] = -1 - 0x7fffffff; snd.fm.buffer[1][len] = -1 - 0x7fffffff;
else else
snd.fm.buffer[1][len] = (long)scaled_value; snd.fm.buffer[1][len] = lrint(scaled_value);
} }
} }

1
source/sound/sound.h
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@ -28,6 +28,7 @@
extern int fm_reg[2][0x100]; extern int fm_reg[2][0x100];
extern double fm_timera_tab[0x400]; extern double fm_timera_tab[0x400];
extern double fm_timerb_tab[0x100]; extern double fm_timerb_tab[0x100];
extern float *src_buffer;
/* Function prototypes */ /* Function prototypes */
extern void sound_init(int rate); extern void sound_init(int rate);

42
source/system.c
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@ -35,6 +35,7 @@ uint32 count_z80;
uint32 line_z80; uint32 line_z80;
int32 current_z80; int32 current_z80;
uint8 system_hw; uint8 system_hw;
SRC_DATA src_data;
static inline void audio_update (void); static inline void audio_update (void);
@ -65,9 +66,13 @@ void system_reset (void)
SN76489_Reset(0); SN76489_Reset(0);
/* Sound Buffers */ /* Sound Buffers */
memset (snd.psg.buffer, 0, SND_SIZE); if (snd.psg.buffer) memset(snd.psg.buffer, 0, SND_SIZE);
memset (snd.fm.buffer[0], 0, SND_SIZE*2); if (snd.fm.buffer[0]) memset(snd.fm.buffer[0], 0, SND_SIZE*2);
memset (snd.fm.buffer[1], 0, SND_SIZE*2); if (snd.fm.buffer[1]) memset(snd.fm.buffer[1], 0, SND_SIZE*2);
/* SRC */
if (src_data.data_in) memset(src_data.data_in, 0, src_data.input_frames * 2 * sizeof(float));
if (src_data.data_out) memset(src_data.data_out,0, src_data.output_frames * 2 * sizeof(float));
} }
/**************************************************************** /****************************************************************
@ -275,28 +280,30 @@ int audio_init (int rate)
snd.buffer[0] = (int16 *) malloc(SND_SIZE); snd.buffer[0] = (int16 *) malloc(SND_SIZE);
snd.buffer[1] = (int16 *) malloc(SND_SIZE); snd.buffer[1] = (int16 *) malloc(SND_SIZE);
if (!snd.buffer[0] || !snd.buffer[1]) return (-1); if (!snd.buffer[0] || !snd.buffer[1]) return (-1);
memset (snd.buffer[0], 0, SND_SIZE);
memset (snd.buffer[1], 0, SND_SIZE);
#endif #endif
/* YM2612 stream buffers */ /* YM2612 stream buffers */
snd.fm.buffer[0] = (int *)malloc (SND_SIZE*2); snd.fm.buffer[0] = (int *)malloc (SND_SIZE*2);
snd.fm.buffer[1] = (int *)malloc (SND_SIZE*2); snd.fm.buffer[1] = (int *)malloc (SND_SIZE*2);
if (!snd.fm.buffer[0] || !snd.fm.buffer[1]) return (-1); if (!snd.fm.buffer[0] || !snd.fm.buffer[1]) return (-1);
memset (snd.fm.buffer[0], 0, SND_SIZE*2);
memset (snd.fm.buffer[1], 0, SND_SIZE*2);
/* SRC buffers */ /* YM2612 resampling */
src_data.data_in = NULL;
src_data.data_out = NULL;
if (config.hq_fm && !config.fm_core) if (config.hq_fm && !config.fm_core)
{ {
snd.fm.src_out = (float *) malloc(snd.buffer_size*2*sizeof(float)); /* initialize SRC */
if (!snd.fm.src_out) return (-1); src_data.input_frames = (int)(((double)m68cycles_per_line * (double)lines_per_frame / 144.0) + 0.5);
src_data.output_frames = snd.buffer_size;
src_data.data_in = (float *)malloc(src_data.input_frames * 2 * sizeof(float));
src_data.data_out = (float *)malloc(src_data.output_frames * 2 * sizeof(float));
src_data.src_ratio = (double)src_data.output_frames / (double)src_data.input_frames;
if (!src_data.data_in || !src_data.data_out) return (-1);
} }
/* SN76489 stream buffers */ /* SN76489 stream buffers */
snd.psg.buffer = (int16 *)malloc (SND_SIZE); snd.psg.buffer = (int16 *)malloc (SND_SIZE);
if (!snd.psg.buffer) return (-1); if (!snd.psg.buffer) return (-1);
memset (snd.psg.buffer, 0, SND_SIZE);
/* Set audio enable flag */ /* Set audio enable flag */
snd.enabled = 1; snd.enabled = 1;
@ -314,8 +321,9 @@ void audio_shutdown(void)
if (snd.buffer[1]) free(snd.buffer[1]); if (snd.buffer[1]) free(snd.buffer[1]);
if (snd.fm.buffer[0]) free(snd.fm.buffer[0]); if (snd.fm.buffer[0]) free(snd.fm.buffer[0]);
if (snd.fm.buffer[1]) free(snd.fm.buffer[1]); if (snd.fm.buffer[1]) free(snd.fm.buffer[1]);
if (snd.fm.src_out) free(snd.fm.src_out);
if (snd.psg.buffer) free(snd.psg.buffer); if (snd.psg.buffer) free(snd.psg.buffer);
if (src_data.data_in) free(src_data.data_in);
if (src_data.data_out) free(src_data.data_out);
} }
static int ll, rr; static int ll, rr;
@ -324,8 +332,8 @@ static inline void audio_update (void)
{ {
int i; int i;
int l, r; int l, r;
double psg_preamp = config.psg_preamp; int psg_preamp = config.psg_preamp;
double fm_preamp = config.fm_preamp; int fm_preamp = config.fm_preamp;
int boost = config.boost; int boost = config.boost;
int filter = config.filter; int filter = config.filter;
@ -339,9 +347,9 @@ static inline void audio_update (void)
/* mix samples */ /* mix samples */
for (i = 0; i < snd.buffer_size; i ++) for (i = 0; i < snd.buffer_size; i ++)
{ {
l = r = (int) ((double)snd.psg.buffer[i] * psg_preamp); l = r = (snd.psg.buffer[i] * psg_preamp) / 100;
l += (int) ((double)snd.fm.buffer[0][i] * fm_preamp); l += ((snd.fm.buffer[0][i] * fm_preamp) / 100);
r += (int) ((double)snd.fm.buffer[1][i] * fm_preamp); r += ((snd.fm.buffer[1][i] * fm_preamp) / 100);
snd.fm.buffer[0][i] = 0; snd.fm.buffer[0][i] = 0;
snd.fm.buffer[1][i] = 0; snd.fm.buffer[1][i] = 0;
snd.psg.buffer[i] = 0; snd.psg.buffer[i] = 0;

4
source/system.h
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@ -24,6 +24,8 @@
#ifndef _SYSTEM_H_ #ifndef _SYSTEM_H_
#define _SYSTEM_H_ #define _SYSTEM_H_
#include "samplerate.h"
#define SYSTEM_GENESIS 0 #define SYSTEM_GENESIS 0
#define SYSTEM_MEGADRIVE 1 #define SYSTEM_MEGADRIVE 1
#define SYSTEM_PICO 2 #define SYSTEM_PICO 2
@ -66,7 +68,6 @@ typedef struct
int curStage; int curStage;
int lastStage; int lastStage;
int *buffer[2]; int *buffer[2];
float *src_out; /* SRC conversion buffer */
} fm; } fm;
struct struct
{ {
@ -86,6 +87,7 @@ extern uint32 count_z80;
extern uint32 line_z80; extern uint32 line_z80;
extern int32 current_z80; extern int32 current_z80;
extern uint8 system_hw; extern uint8 system_hw;
extern SRC_DATA src_data;
/* Function prototypes */ /* Function prototypes */
extern void system_init (void); extern void system_init (void);

48
source/vdp.c
View File

@ -91,9 +91,6 @@ static uint16 sat_base_mask; /* Base bits of SAT */
static uint16 sat_addr_mask; /* Index bits of SAT */ static uint16 sat_addr_mask; /* Index bits of SAT */
static uint32 dma_endCycles; /* 68k cycles to DMA end */ static uint32 dma_endCycles; /* 68k cycles to DMA end */
static uint8 dma_type; /* Type of DMA */ static uint8 dma_type; /* Type of DMA */
static double vdp_timings[4][4]; /* DMA timings */
static inline void vdp_reg_w(unsigned int r, unsigned int d);
/* DMA Timings /* DMA Timings
@ -122,31 +119,22 @@ static inline void vdp_reg_w(unsigned int r, unsigned int d);
CRAM or VSRAM for a 68K > VDP transfer, in which case it is in words. CRAM or VSRAM for a 68K > VDP transfer, in which case it is in words.
*/ */
static const uint8 dma_rates[16] = { static const uint32 dma_rates[16] = {
8, 9, 83 , 102, /* 68K to VRAM */ 8, 83, 9, 102, /* 68K to VRAM (1 word = 2 bytes) */
16, 18, 167, 205, /* 68K to CRAM or VSRAM */ 16, 167, 18, 205, /* 68K to CRAM or VSRAM */
15, 17, 166, 204, /* DMA fill */ 15, 166, 17, 204, /* DMA fill */
8, 9, 83 , 102, /* DMA Copy */ 8, 83, 9, 102, /* DMA Copy */
}; };
/* Function prototypes */ /* Function prototypes */
static inline void data_write(unsigned int data); static inline void data_write(unsigned int data);
static inline void vdp_reg_w(unsigned int r, unsigned int d);
/*--------------------------------------------------------------------------*/ /*--------------------------------------------------------------------------*/
/* Init, reset, shutdown functions */ /* Init, reset, shutdown functions */
/*--------------------------------------------------------------------------*/ /*--------------------------------------------------------------------------*/
void vdp_init(void) void vdp_init(void)
{ {
/* reinitialize DMA timings table */
int i;
for (i=0; i<4; i++)
{
vdp_timings[0][i] = ((double)m68cycles_per_line) / ((double) dma_rates[i]);
vdp_timings[1][i] = ((double)m68cycles_per_line) / ((double) dma_rates[i + 4]);
vdp_timings[2][i] = ((double)m68cycles_per_line) / ((double) dma_rates[i + 8]);
vdp_timings[3][i] = ((double)m68cycles_per_line) / ((double) dma_rates[i + 12]);
}
/* PAL/NTSC timings */ /* PAL/NTSC timings */
vdp_rate = vdp_pal ? 50 : 60; vdp_rate = vdp_pal ? 50 : 60;
lines_per_frame = vdp_pal ? 313 : 262; lines_per_frame = vdp_pal ? 313 : 262;
@ -280,24 +268,27 @@ void vdp_restore(uint8 *vdp_regs)
/* Update DMA timings (this is call on start of DMA and then at the start of each scanline) */ /* Update DMA timings (this is call on start of DMA and then at the start of each scanline) */
void dma_update() void dma_update()
{ {
int32 left_cycles; int dma_cycles = 0;
uint32 dma_cycles, dma_bytes;
uint8 index = 0;
/* get the appropriate tranfer rate (bytes/line) for this DMA operation */ /* DMA timings table index */
if ((status&8) || !(reg[1] & 0x40)) index = 2; /* VBLANK or Display OFF */ int index = (4 * dma_type) + ((reg[12] & 1)*2);
index += (reg[12] & 1); /* 32 or 40 Horizontal Cells */ if ((status&8) || !(reg[1] & 0x40)) index++;
/* calculate transfer quantity for the remaining 68k cycles */ /* DMA transfer rate */
left_cycles = line_m68k + m68cycles_per_line - count_m68k; int rate = dma_rates[index];
/* 68k cycles left */
int left_cycles = (line_m68k + m68cycles_per_line) - count_m68k;
if (left_cycles < 0) left_cycles = 0; if (left_cycles < 0) left_cycles = 0;
dma_bytes = (uint32)(((double)left_cycles / vdp_timings[dma_type][index]) + 0.5);
/* DMA bytes left */
int dma_bytes = (left_cycles * rate) / m68cycles_per_line;
/* determinate DMA length in CPU cycles */ /* determinate DMA length in CPU cycles */
if (dma_length < dma_bytes) if (dma_length < dma_bytes)
{ {
/* DMA will be finished during this line */ /* DMA will be finished during this line */
dma_cycles = (uint32)(((double)dma_length * vdp_timings[dma_type][index]) + 0.5); dma_cycles = (dma_length * m68cycles_per_line) / rate;
dma_length = 0; dma_length = 0;
} }
else else
@ -307,6 +298,7 @@ void dma_update()
dma_length -= dma_bytes; dma_length -= dma_bytes;
} }
/* update 68k cycles counter */
if (dma_type < 2) if (dma_type < 2)
{ {
/* 68K COPY to V-RAM */ /* 68K COPY to V-RAM */