better algorithm to load bytes

src/spider/runtime/reel/InstrReelFixed.cpp

@@ -47,49 +47,36 @@ namespace spider {
     // Instruction abstraction //
 
     u8 InstrReelFixed::readU8(u64 ip) {
-        // guard against access
-        if(ip + 1 > _size) return 0;
-
-        // send byte
-        return _mem[ip];
+        u8 dat;
+        spider::loadPartialLE(&dat, _mem + ip, _size);
+        return dat;
     }
 
     u16 InstrReelFixed::readU16(u64 ip) {
-        // guard against access
-        if(ip + 2 > _size) return 0;
-
-        // build a 16-bit big endian number
         u16 dat;
-        spider::loadLE(&dat, _mem + ip);
+        spider::loadPartialLE(&dat, _mem + ip, _size);
         return dat;
     }
 
     u32 InstrReelFixed::readU32(u64 ip) {
-        // guard against access
-        if(ip + 4 > _size) return 0;
-
-        // build a 32-bit big endian number
         u32 dat;
-        spider::loadLE(&dat, _mem + ip);
+        spider::loadPartialLE(&dat, _mem + ip, _size);
         return dat;
     }
 
     u64 InstrReelFixed::readU64(u64 ip) {
-        // guard against access
-        if(ip + 8 > _size) return 0;
-
-        // build a 64-bit big endian number
         u64 dat;
-        spider::loadLE(&dat, _mem + ip);
+        spider::loadPartialLE(&dat, _mem + ip, _size);
         return dat;
     }
 
     void InstrReelFixed::readRange(u64 ip, u8* out, u64 length) {
-        if(ip + length > _size) {
-            std::memset(out, 0, length);
-            return;
-        }
-        std::memcpy(out, _mem + ip, length);
+        spider::loadPartialBytes(_mem, isize(ip), _size, out, length);
+    }
+
+    void InstrReelFixed::loadRegister(u64 ip, u8 size_code, register_t* r) {
+        ip = std::min(ip, _size);
+        spider::loadRegister[size_code](r, _mem + ip, _size - ip);
     }
 
     u64 InstrReelFixed::size() {