Avoid cache miss when getting instruct func (#33)

This makes the instruction array a global variable. This improves performance by ~3ns/op. This also includes a new Benchmark for ExecuteNextOpcode()
Humpheh · Aug 9, 2020 · da8716d · da8716d
1 parent 84af8fa
commit da8716d
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Showing 3 changed files with 1,182 additions and 1,182 deletions.
diff --git a/pkg/gb/gameboy.go b/pkg/gb/gameboy.go
@@ -48,8 +48,7 @@ type Gameboy struct {
 	interruptsOn       bool
 	halted             bool
 
-	mainInst [0x100]func()
-	cbInst   [0x100]func()
+	cbInst [0x100]func()
 
 	// Mask of the currently pressed buttons.
 	inputMask byte
@@ -339,7 +338,6 @@ func (gb *Gameboy) setup() {
 	gb.scanlineCounter = 456
 	gb.inputMask = 0xFF
 
-	gb.mainInst = gb.mainInstructions()
 	gb.cbInst = gb.cbInstructions()
 
 	gb.SpritePalette = NewPalette()