refactor: Rework asmap Interpret to avoid ptrdiff_t

Author: Empact

src/util/asmap.cpp

@@ -93,7 +93,8 @@ uint32_t Interpret(const std::vector<bool> &asmap, const std::vector<bool> &ip)
             jump = DecodeJump(pos, endpos);
             if (jump == INVALID) break; // Jump offset straddles EOF
             if (bits == 0) break; // No input bits left
-            if (jump >= endpos - pos) break; // Jumping past EOF
+            if (pos + jump < pos) break; // overflow
+            if (pos + jump >= endpos) break; // Jumping past EOF
             if (ip[ip.size() - bits]) {
                 pos += jump;
             }
@@ -155,7 +156,8 @@ bool SanityCheckASMap(const std::vector<bool>& asmap, int bits)
         } else if (opcode == Instruction::JUMP) {
             uint32_t jump = DecodeJump(pos, endpos);
             if (jump == INVALID) return false; // Jump offset straddles EOF
-            if (jump > endpos - pos) return false; // Jump out of range
+            if (pos + jump < pos) return false; // overflow
+            if (pos + jump > endpos) return false; // Jump out of range
             if (bits == 0) return false; // Consuming bits past the end of the input
             --bits;
             uint32_t jump_offset = pos - begin + jump;