From e347ef271364bdd1933c14f9c390b2f5a5cc50d5 Mon Sep 17 00:00:00 2001
From: EkeEke <ekeeke31@gmail.com>
Date: Thu, 9 Jul 2015 23:49:41 +0200
Subject: [PATCH] [Core/CD] minor optimization

---
 core/cd_hw/cdc.c | 15 +++++----------
 core/cd_hw/cdc.h |  2 +-
 core/cd_hw/scd.c |  2 +-
 3 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/core/cd_hw/cdc.c b/core/cd_hw/cdc.c
index dd75a59..cf24c9b 100644
--- a/core/cd_hw/cdc.c
+++ b/core/cd_hw/cdc.c
@@ -243,7 +243,7 @@ void cdc_dma_update(void)
   }
 }
 
-int cdc_decoder_update(uint32 header)
+void cdc_decoder_update(uint32 header)
 {
   /* data decoding enabled ? */
   if (cdc.ctrl[0] & BIT_DECEN)
@@ -274,7 +274,7 @@ int cdc_decoder_update(uint32 header)
     /* buffer RAM write enabled ? */
     if (cdc.ctrl[0] & BIT_WRRQ)
     {
-      uint16 offset;
+      int offset;
 
       /* increment block pointer  */
       cdc.pt.w += 2352;
@@ -292,19 +292,14 @@ int cdc_decoder_update(uint32 header)
       cdd_read_data(cdc.ram + 4 + offset);
 
       /* take care of buffer overrun */
-      if (offset > (0x4000 - 2048 - 4))
+      offset = offset + 2048 + 4 - 0x4000;
+      if (offset > 0)
       {
         /* data should be written at the start of buffer */
-        memcpy(cdc.ram, cdc.ram + 0x4000, offset + 2048 + 4 - 0x4000);
+        memcpy(cdc.ram, cdc.ram + 0x4000, offset);
       }
-
-      /* read next data block */
-      return 1;
     }
   }
-  
-  /* keep decoding same data block if Buffer Write is disabled */
-  return 0;
 }
 
 void cdc_reg_w(unsigned char data)
diff --git a/core/cd_hw/cdc.h b/core/cd_hw/cdc.h
index 651f992..dcd1610 100644
--- a/core/cd_hw/cdc.h
+++ b/core/cd_hw/cdc.h
@@ -63,7 +63,7 @@ extern void cdc_reset(void);
 extern int cdc_context_save(uint8 *state);
 extern int cdc_context_load(uint8 *state);
 extern void cdc_dma_update(void);
-extern int cdc_decoder_update(uint32 header);
+extern void cdc_decoder_update(uint32 header);
 extern void cdc_reg_w(unsigned char data);
 extern unsigned char cdc_reg_r(void);
 extern unsigned short cdc_host_r(void);
diff --git a/core/cd_hw/scd.c b/core/cd_hw/scd.c
index c2a1abd..91e7868 100644
--- a/core/cd_hw/scd.c
+++ b/core/cd_hw/scd.c
@@ -1480,7 +1480,7 @@ void scd_init(void)
 
       case 0x0e:
       {
-        /* $FE0000-$FEFFFF (mirrored every 1MB): 8KB backup RAM (Wonder Mega / X'Eye BIOS access it at $FD0000-$FD1FFF ?) */
+        /* $FE0000-$FEFFFF (mirrored every 1MB): 8KB backup RAM */
         s68k.memory_map[i].base     = NULL;
         s68k.memory_map[i].read8    = bram_read_byte;
         s68k.memory_map[i].read16   = bram_read_word;