From: notaz <notasas@gmail.com>
Date: Sat, 30 Sep 2017 22:29:08 +0000 (+0300)
Subject: some poor timing improvement attempts
X-Git-Tag: v1.92~16
X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?p=picodrive.git;a=commitdiff_plain;h=d1b8bcc63466f6982685df518db8fef399f9cf91

some poor timing improvement attempts
---

diff --git a/pico/memory.c b/pico/memory.c
index 34ef99d..3900208 100644
--- a/pico/memory.c
+++ b/pico/memory.c
@@ -1195,6 +1195,8 @@ void PicoWrite16_32x(u32 a, u32 d) {}
 
 static unsigned char z80_md_vdp_read(unsigned short a)
 {
+  z80_subCLeft(2);
+
   if ((a & 0x00f0) == 0x0000) {
     switch (a & 0x0d)
     {
@@ -1218,8 +1220,10 @@ static unsigned char z80_md_bank_read(unsigned short a)
   unsigned int addr68k;
   unsigned char ret;
 
-  addr68k = Pico.m.z80_bank68k<<15;
-  addr68k += a & 0x7fff;
+  z80_subCLeft(3);
+
+  addr68k = Pico.m.z80_bank68k << 15;
+  addr68k |= a & 0x7fff;
 
   ret = m68k_read8(addr68k);
 
diff --git a/pico/pico_int.h b/pico/pico_int.h
index 97b7b0e..f439d6a 100644
--- a/pico/pico_int.h
+++ b/pico/pico_int.h
@@ -185,6 +185,7 @@ extern struct DrZ80 drZ80;
 #define z80_nmi()          drZ80.Z80IF |= 8
 
 #define z80_cyclesLeft     drZ80.cycles
+#define z80_subCLeft(c)    drZ80.cycles -= c
 #define z80_pc()           (drZ80.Z80PC - drZ80.Z80PC_BASE)
 
 #elif defined(_USE_CZ80)
@@ -196,6 +197,7 @@ extern struct DrZ80 drZ80;
 #define z80_nmi()          Cz80_Set_IRQ(&CZ80, IRQ_LINE_NMI, 0)
 
 #define z80_cyclesLeft     (CZ80.ICount - CZ80.ExtraCycles)
+#define z80_subCLeft(c)    CZ80.ICount -= c
 #define z80_pc()           Cz80_Get_Reg(&CZ80, CZ80_PC)
 
 #else