From 396b10dd5e206462ebeab5fed368ba3ae25c6a51 Mon Sep 17 00:00:00 2001
From: Peter Fors <peter.fors@mindkiller.com>
Date: Sat, 25 Oct 2025 21:56:37 +0200
Subject: Better benchmarking, some small optimizations

---
 mknes_memory.c | 79 ++++++++++++++++++++++++++++++----------------------------
 1 file changed, 41 insertions(+), 38 deletions(-)

(limited to 'mknes_memory.c')

diff --git a/mknes_memory.c b/mknes_memory.c
index 7b74424..49546b2 100644
--- a/mknes_memory.c
+++ b/mknes_memory.c
@@ -5,6 +5,8 @@ static inline uint8_t memory_read(struct nes_state *state, uint32_t offset) {
 	apu_tick(state);
 	ppu_tick(state);
 
+	if(offset >= 0x10000) __builtin_unreachable();
+
 	if(offset <= 0x1fff) {
 		return state->ram[offset & 0x07ff];
 	}
@@ -55,55 +57,56 @@ static inline void memory_write(struct nes_state *state, uint32_t offset, uint8_
 	apu_tick(state);
 	ppu_tick(state);
 
-	switch(offset) {
-		case 0x0000 ... 0x1fff: {
-			state->ram[offset & 0x07ff] = value;
-		} break;
+	if(offset >= 0x10000) __builtin_unreachable();
 
+	if(offset <= 0x1fff) {
+		state->ram[offset & 0x07ff] = value;
+		return;
+	}
 
-		case 0x2000 ... 0x3fff: {
-			ppu_write(state, offset, value);
-		} break;
+	if(offset >= 0x8000) {
+		state->mapper_function.prg_rom_write(state, offset, value);
+		return;
+	}
 
-		case 0x4000 ... 0x4017: {
-			switch(offset) {
-				case 0x4014: {
-					ppu_dma_4014(state, value);
-				} break;
+	if(offset >= 0x2000 && offset <= 0x3fff) {
+		ppu_write(state, offset, value);
+		return;
+	}
 
-				case 0x4016: {
-					// joypad strobe
-					uint8_t s = value & 1;
+	if(offset == 0x4014) {
+		ppu_dma_4014(state, value);
+		return;
+	}
 
-					// if(s) {
-						uint8_t prev = state->ppu.input_strobe;
-						state->ppu.input_strobe = s;
+	if(offset == 0x4016) {
+		// joypad strobe
+		uint8_t s = value & 1;
 
-						if(prev == 1 && (s) == 0) {
-							// state->ppu.input[0] = tas_input[tas_frame_count];
+		// if(s) {
+			uint8_t prev = state->ppu.input_strobe;
+			state->ppu.input_strobe = s;
 
-							state->ppu.input_latch[0] = state->ppu.input[0];
-							state->ppu.input_latch[1] = state->ppu.input[1];
-							state->ppu.input_bit[0] = 0;
-							state->ppu.input_bit[1] = 0;
-						}
-					// }
-				} break;
+			if(prev == 1 && (s) == 0) {
+				// state->ppu.input[0] = tas_input[tas_frame_count];
 
-				default: {
-					apu_write(state, offset, value);
-				} break;
+				state->ppu.input_latch[0] = state->ppu.input[0];
+				state->ppu.input_latch[1] = state->ppu.input[1];
+				state->ppu.input_bit[0] = 0;
+				state->ppu.input_bit[1] = 0;
 			}
-		} break;
-
-		case 0x6000 ... 0x7fff: {
-			state->mapper_function.prg_ram_write(state, offset, value);
-		} break;
+		// }
+		return;
+	}
 
-		case 0x8000 ... 0xffff: {
-			state->mapper_function.prg_rom_write(state, offset, value);
-		} break;
+	if(offset >= 0x4000 && offset <= 0x4017) {
+		apu_write(state, offset, value);
+		return;
+	}
 
+	if(offset >= 0x6000 && offset <= 0x7fff) {
+		state->mapper_function.prg_ram_write(state, offset, value);
+		return;
 	}
 }
 
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