+extern int cache_isolated;
+
+#ifndef DISABLE_MEM_LUTS
+#define DISABLE_MEM_LUTS 0
+#endif
+
+static inline void * psxm_lut(u32 mem, int write, u8 **lut)
+{
+ if (!DISABLE_MEM_LUTS) {
+ void *ptr = lut[mem >> 16];
+
+ return ptr == INVALID_PTR ? INVALID_PTR : ptr + (u16)mem;
+ }
+
+ if (mem >= 0xa0000000)
+ mem -= 0xa0000000;
+ else
+ mem &= ~0x80000000;
+
+ if (mem < 0x800000) {
+ if (cache_isolated)
+ return INVALID_PTR;
+
+ return &psxM[mem & 0x1fffff];
+ }
+
+ if (mem > 0x1f800000 && mem <= 0x1f810000)
+ return &psxH[mem - 0x1f800000];
+
+ if (!write) {
+ if (mem > 0x1fc00000 && mem <= 0x1fc80000)
+ return &psxR[mem - 0x1fc00000];
+
+ if (mem > 0x1f000000 && mem <= 0x1f010000)
+ return &psxP[mem - 0x1f000000];
+ }
+
+ return INVALID_PTR;
+}
+
+static inline void * psxm(u32 mem, int write)
+{
+ return psxm_lut(mem, write, write ? psxMemWLUT : psxMemRLUT);
+}