audio reduced logic optimization

Author: Niko

decompile/General/CDSYS/CDSYS_07_SpuCallbackIRQ.c

@@ -17,7 +17,7 @@ half.
   // from TOMB5
   // https://github.com/TOMB5/TOMB5/blob/master/EMULATOR/LIBSPU.H
   #define SPU_CDONLY	5
-  SpuReadDecodedData(&sdata->SpuDecodedData[0], SPU_CDONLY);
+  SpuReadDecodedData(&sdata->SpuReadbackDst[0], SPU_CDONLY);
 
   if(
 	  (sdata->XA_boolFinished == 0) &&

decompile/General/CDSYS/CDSYS_08_SpuCallbackTransfer.c

@@ -2,13 +2,11 @@
 
 void DECOMP_CDSYS_SpuCallbackTransfer()
 {
-	if (sdata->irqAddr == 0)
-		sdata->irqAddr = 0x200;
+	// 0->1, and 1->0
+	sdata->irqAddr = sdata->irqAddr + 1;
+	sdata->irqAddr = sdata->irqAddr & 2;
 
-	else
-		sdata->irqAddr = 0;
-	
-	SpuSetIRQAddr(sdata->irqAddr);
+	SpuSetIRQAddr(sdata->irqAddr << 9);
 	SpuSetIRQ(1);
 
 #if 0 // unused

decompile/General/CDSYS/CDSYS_09_SpuEnableIRQ.c

@@ -4,14 +4,14 @@ void DECOMP_CDSYS_SpuEnableIRQ()
 {
 	for(int i = 0; i < 0x100; i++)
 	{
-		sdata->SpuDecodedData[i] = 0;
+		sdata->SpuReadbackDst[i] = 0;
 	}
 
 	SpuSetTransferMode(SPU_TRANSFER_BY_DMA);
 	SpuSetTransferCallback(DECOMP_CDSYS_SpuCallbackTransfer);
 	SpuSetIRQCallback(DECOMP_CDSYS_SpuCallbackIRQ);
 
-	sdata->irqAddr = 0x200;
-	SpuSetIRQAddr(0x200);
+	sdata->irqAddr = 1;
+	SpuSetIRQAddr(sdata->irqAddr << 9);
 	SpuSetIRQ(1);
 }

decompile/General/CDSYS/CDSYS_11_SpuGetMaxSample.c

@@ -12,29 +12,19 @@ void DECOMP_CDSYS_SpuGetMaxSample(void)
     // if you are not using CD, quit
     if (sdata->boolUseDisc == false) return;
 
-	// irqAddr = 0, index = {0x000 - 0x100}, byteRange = {0x000 - 0x200}, 
-	// irqAddr = 1, index = {0x100 - 0x200}, byteRange = {0x200 - 0x400}, 
-
 	// this irqAddr value changes in CDSYS_SpuCallbackTransfer,
 	// meaning this might always be 1 frame behind, even in retail CTR
 
-    if (sdata->irqAddr == 0)
-    {
-        currIndex = 0;
-        endIndex = 0x100;
-    }
-	
-    else
-    {
-		currIndex = 0x100;
-        endIndex = 0x200;
-    }
+	// loop through 0x100 short's is 0x200 bytes
+	short* arrSpuReadbackDst = 
+		&sdata->SpuReadbackDst[sdata->irqAddr << 9];
 
     // loop through region
-    for (max = 0; currIndex < endIndex; currIndex++)
+	max = 0;
+    for (int i = 0; i < 0x100; i++)
     {
 		// absolute value
-        sample = sdata->SpuDecodedData[currIndex];
+        sample = arrSpuReadbackDst[i];
         if (sample < 0) sample = -sample;
 
 		// find max

include/regionsEXE.h

@@ -4508,9 +4508,9 @@ struct sData
 	// 80091198 -- JpnRetail
 	// see FUN_8001c8e4
 	#if BUILD == SepReview
-	short SpuDecodedData[0x800];
+	char SpuReadbackDst[0x1000];
 	#elif BUILD >= UsaRetail
-	short SpuDecodedData[0x400];
+	char SpuReadbackDst[0x800];
 	#endif
 
 	// 8008E528