From f1bd6a7d2f4ffe3e5263e0254bcf7522ab381264 Mon Sep 17 00:00:00 2001
From: Peter Fors <peter.fors@mindkiller.com>
Date: Sat, 5 Apr 2025 08:58:12 +0200
Subject: transform to switch case for ppu_tick()

---
 memory.c | 76 +++++++++++++++++-----------------------------------------------
 1 file changed, 20 insertions(+), 56 deletions(-)

(limited to 'memory.c')

diff --git a/memory.c b/memory.c
index e0ed85a..28c51ad 100644
--- a/memory.c
+++ b/memory.c
@@ -1,97 +1,61 @@
 
 
 
+__attribute__((hot))
 static uint8_t memory_read(struct nes_state *restrict state, uint32_t offset) {
 	state->cycles++;
-	ppu_tick(state); ppu_tick(state); ppu_tick(state);
+	ppu_tick(state);
 
-	if(offset > 0xffff) {
-		printf("%x\n", offset);
-	}
-
-	// state->ram[0x301] = 0x1;
-	if(offset < 0x2000) {
+	if(LIKELY(offset < 0x2000)) {
 		return state->ram[offset & 0x07ff];
 	} else if(offset < 0x4000) {
 		return ppu_read(state, offset);
-		// switch(offset & 7) {
-		// 	case 2: return ppu_read_2002(state);
-		// 	case 4: return ppu_read_2004(state);
-		// 	case 7: return ppu_read_2007(state);
-		// 	default: return 0;
-		// }
-	} else if(offset < 0x4020) {
-		// TODO: APU and I/O reads
-		return 0;
-	} else if(offset >= 0x6000) {
+	// } else if(offset < 0x4020) {
+	// 	// TODO: APU and I/O reads
+	// 	return 0;
+	} else if(LIKELY(offset >= 0x6000)) {
 		return state->mapper.prg_read(state, offset);
-	} else {
-		return 0;
 	}
+	return 0;
 }
 
+__attribute__((hot))
 static void memory_write(struct nes_state *restrict state, uint32_t offset, uint8_t value) {
 	state->cycles++;
-	ppu_tick(state); ppu_tick(state); ppu_tick(state);
-
-	if(offset > 0xffff) {
-		printf("%x\n", offset);
-	}
+	ppu_tick(state);
 
-	if(offset < 0x2000) {
+	if(LIKELY(offset < 0x2000)) {
 		state->ram[offset & 0x07ff] = value;
 	} else if(offset < 0x4000) {
 		ppu_write(state, offset, value);
-		// switch(offset & 7) {
-		// 	case 0: ppu_write_2000(state, value); break;
-		// 	case 1: ppu_write_2001(state, value); break;
-		// 	case 3: ppu_write_2003(state, value); break;
-		// 	case 4: ppu_write_2004(state, value); break;
-		// 	case 5: ppu_write_2005(state, value); break;
-		// 	case 6: ppu_write_2006(state, value); break;
-		// 	case 7: ppu_write_2007(state, value); break;
-		// 	default: break;
-		// }
 	} else if(offset == 0x4014) {
 		ppu_dma_4014(state, value);
-	} else if(offset < 0x4020) {
-		// TODO: APU and I/O writes
+	// } else if(offset < 0x4020) {
+	// 	// TODO: APU and I/O writes
 	} else if(offset >= 0x6000) {
 		state->mapper.prg_write(state, offset, value);
 	}
 }
 
+__attribute__((hot))
 static uint8_t memory_read_dma(struct nes_state *restrict state, uint32_t offset) {
 	// Do not tick CPU/PPU/APU — caller handles timing
-	if(offset < 0x2000) {
+	if(LIKELY(offset < 0x2000)) {
 		return state->ram[offset & 0x07ff];
-	} else if(offset < 0x4000) {
-		// PPU register reads are ignored during DMA
-		return 0;
-	} else if(offset < 0x4020) {
-		// APU and I/O — usually ignored or blocked during DMA
-		return 0;
 	} else if(offset >= 0x6000) {
 		return state->mapper.prg_read(state, offset);
-	} else {
-		return 0;
 	}
+	return 0;
 }
 
+__attribute__((hot))
 static uint8_t memory_read_dummy(struct nes_state *restrict state, uint32_t offset) {
 	state->cycles++;
-	ppu_tick(state); ppu_tick(state); ppu_tick(state);
+	ppu_tick(state);
 
-	if(offset < 0x2000) {
-		return 0;
-	} else if(offset < 0x4000) {
+	if(UNLIKELY(offset >= 0x2000 && offset < 0x4000)) {
 		return ppu_read(state, offset);
-	} else if(offset < 0x4020) {
-		return 0;
-	} else if(offset >= 0x6000) {
-		return state->mapper.prg_read(state, offset);
-	} else {
-		return 0;
 	}
+	return 0;
 }
 
-- 
cgit v1.2.3