From 170435846c8e2309dc4011f954287f9ea861a6b6 Mon Sep 17 00:00:00 2001
From: notaz <notasas@gmail.com>
Date: Sun, 25 May 2008 21:01:55 +0000
Subject: [PATCH] improved irq handling Cz80_Exec() calls with lots of cycles

git-svn-id: file:///home/notaz/opt/svn/PicoDrive@458 be3aeb3a-fb24-0410-a615-afba39da0efa
---
 cpu/DrZ80/drz80.s  | 40 +++++++++++++++++-----------------------
 cpu/cz80/cz80.c    |  2 ++
 cpu/cz80/cz80.h    |  2 +-
 cpu/cz80/cz80_op.c |  4 +++-
 4 files changed, 23 insertions(+), 25 deletions(-)

diff --git a/cpu/DrZ80/drz80.s b/cpu/DrZ80/drz80.s
index ee14013..9b07a13 100644
--- a/cpu/DrZ80/drz80.s
+++ b/cpu/DrZ80/drz80.s
@@ -106,21 +106,6 @@ DrZ80Ver: .long 0x0001
 
 .if DRZ80_FOR_PICODRIVE
 
-.macro YM2612Read_and_ret8
-    ldr r0, =ym2612_st
-    ldr r0, [r0]
-    ldrb r0, [r0, #0x11]   ;@ ym2612_st->status
-    bx lr
-.endm
-
-.macro YM2612Read_and_ret16
-    ldr r0, =ym2612_st
-    ldr r0, [r0]
-    ldrb r0, [r0, #0x11]   ;@ ym2612_st->status
-    orr r0,r0,r0,lsl #8
-    bx lr
-.endm
-
 pico_z80_read8: @ addr
     cmp r0,#0x2000         @ Z80 RAM
     ldrlt r1,[cpucontext,#z80sp_base]
@@ -139,15 +124,18 @@ pico_z80_read8: @ addr
     eorlt r0,r0,#1         @ our ROM is byteswapped
     ldrltb r0,[r1,r0]
     bxlt lr
-	stmfd sp!,{r3,r12,lr}
+    stmfd sp!,{r3,r12,lr}
     bl PicoRead8
-	ldmfd sp!,{r3,r12,pc}
+    ldmfd sp!,{r3,r12,pc}
 1:
     mov r1,r0,lsr #13
     cmp r1,#2              @ YM2612 (0x4000-0x5fff)
     bne 0f
     and r0,r0,#3
-    YM2612Read_and_ret8
+    stmfd sp!,{r3,r12,lr}
+    str z80_icount,[cpucontext,#cycles_pointer]
+    bl ym2612_read_local_z80
+    ldmfd sp!,{r3,r12,pc}
 0:
     cmp r0,#0x4000
     movge r0,#0xff
@@ -197,7 +185,11 @@ pico_z80_read16: @ addr
     cmp r1,#2              @ YM2612 (0x4000-0x5fff)
     bne 0f
     and r0,r0,#3
-    YM2612Read_and_ret16
+    stmfd sp!,{r3,r12,lr}
+    str z80_icount,[cpucontext,#cycles_pointer]
+    bl ym2612_read_local_z80
+    orr r0,r0,r0,lsl #8
+    ldmfd sp!,{r3,r12,pc}
 0:
     cmp r0,#0x4000
     movge r0,#0xff
@@ -218,6 +210,7 @@ pico_z80_write8: @ data, addr
     bx lr
 1:
     stmfd sp!,{r3,r12,lr}
+    str z80_icount,[cpucontext,#cycles_pointer]
     bl z80_write
     ldmfd sp!,{r3,r12,pc}
 
@@ -231,14 +224,15 @@ pico_z80_write16: @ data, addr
     strb r0,[r2,#1]
     bx lr
 1:
-	stmfd sp!,{r3-r5,r12,lr}
+    stmfd sp!,{r3-r5,r12,lr}
+    str z80_icount,[cpucontext,#cycles_pointer]
     mov r4,r0
     mov r5,r1
-	bl z80_write
+    bl z80_write
     mov r0,r4,lsr #8
     add r1,r5,#1
-	bl z80_write
-	ldmfd sp!,{r3-r5,r12,pc}
+    bl z80_write
+    ldmfd sp!,{r3-r5,r12,pc}
 
     .pool
 .endif
diff --git a/cpu/cz80/cz80.c b/cpu/cz80/cz80.c
index d7bdba3..18fd620 100644
--- a/cpu/cz80/cz80.c
+++ b/cpu/cz80/cz80.c
@@ -270,6 +270,8 @@ Cz80_Check_Interrupt:
 			if (CPU->IRQState != CLEAR_LINE)
 			{
 				CHECK_INT
+				CPU->ICount -= CPU->ExtraCycles;
+				CPU->ExtraCycles = 0;
 			}
 			goto Cz80_Exec;
 		}
diff --git a/cpu/cz80/cz80.h b/cpu/cz80/cz80.h
index e097460..d23d793 100644
--- a/cpu/cz80/cz80.h
+++ b/cpu/cz80/cz80.h
@@ -61,7 +61,7 @@ extern "C" {
 //#else
 #define CZ80_ENCRYPTED_ROM		0
 //#endif
-#define CZ80_EMULATE_R_EXACTLY	0
+#define CZ80_EMULATE_R_EXACTLY	1
 
 #define zR8(A)		(*CPU->pzR8[A])
 #define zR16(A)		(CPU->pzR16[A]->W)
diff --git a/cpu/cz80/cz80_op.c b/cpu/cz80/cz80_op.c
index ed13c9e..a4a5ef9 100644
--- a/cpu/cz80/cz80_op.c
+++ b/cpu/cz80/cz80_op.c
@@ -712,8 +712,10 @@ OP_EI:
 			if (CPU->IRQState)
 			{
 				afterEI = 1;
+				CPU->ExtraCycles += 1 - CPU->ICount;
+				CPU->ICount = 1;
 			}
-			if (CPU->ICount <= 0)
+			else if (CPU->ICount <= 0)
 			{
 				CPU->ICount = 1;
 			}
-- 
2.39.2