Minor perf improvements related to number parsing

[sonals]

Problem solved by the commit

Number parsing was taking up 28% of time for the aie4 multi_graph testcase. Improve speed by removing redundant string operations and making the handler table static..

Bug / issue (if any) fixed, which PR introduced the bug, how it was discovered

How problem was solved, alternative solutions (if any) and why they were rejected

valgrind analysis identified the hotspot.

Risks (if any) associated the changes in the commit

Low

What has been tested and how, request additional testing if necessary

ctest validated

Documentation impact (if any)

NA

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[github-actions]

clang-tidy review says "All clean, LGTM! 👍"

[Copilot]

Pull request overview

This PR targets a known hotspot in the assembler’s numeric argument parsing, aiming to reduce overhead in assembler_state::parse_num_arg() during large testcases (e.g., aie4 multi_graph).

Changes:

• Makes the handler lookup table for prefix-based parsing static to avoid per-call construction.
• Reworks tile_<col>_<row> parsing using a compiled regex and extracts row/col via capture groups.
• Simplifies hex parsing by passing the full "0x..." string to std::stoul().

Comments suppressed due to low confidence (1)

src/cpp/common/assembler_state.cpp:170

• handlers is now a function-local static but the stored lambdas capture this. That means the map is initialized once using the first assembler_state instance that calls parse_num_arg(), and subsequent calls (including from other instances) will dereference the wrong this pointer. This is incorrect and can also introduce cross-instance/thread issues. Consider keeping the table non-static, or make the table static but store non-capturing callables (e.g., free functions/member-function pointers that take an assembler_state&/assembler_state* as an explicit parameter).

  static const std::unordered_map<std::string, std::function<uint32_t(const std::string&)>> handlers = {
    {"@", [this](const std::string& s) -> uint32_t {
          //If string start with '@': it can be either pad name or label name
          auto key = s.substr(1);
          if (m_scratchpad.find(key) != m_scratchpad.end())

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[github-actions]

clang-tidy made some suggestions

[github-actions]

warning: member 'handlers' of type 'const std::unordered_map<std::string, std::function<uint32_t (const std::string &)>>' (aka 'const unordered_map<basic_string, function<unsigned int (const basic_string &)>>') is const qualified [cppcoreguidelines-avoid-const-or-ref-data-members]

  const std::unordered_map<std::string, std::function<uint32_t(const std::string&)>> handlers = {
                                                                                     ^