Small IPA passes (GNU Compiler Collection (GCC) Internals) (original) (raw)

8.4.1 Small IPA passes ¶

A small IPA pass is a pass derived from simple_ipa_opt_pass. As described in Using summary information in IPA passes, it does everything at once and defines only the Execute stage. During this stage it accesses and modifies the function bodies. No generate_summary, read_summary, or write_summaryhooks are defined.

• IPA free lang data
  This pass frees resources that are used by the front end but are not needed once it is done. It is located in tree.cc and is described bypass_ipa_free_lang_data.
• IPA function and variable visibility
  This is a local function pass handling visibilities of all symbols. This happens before LTO streaming, so -fwhole-program should be ignored at this level. It is located in ipa-visibility.cc and is described bypass_ipa_function_and_variable_visibility.
• IPA remove symbols
  This pass performs reachability analysis and reclaims all unreachable nodes. It is located in passes.cc and is described bypass_ipa_remove_symbols.
• IPA OpenACC
  This is a pass group for OpenACC processing. It is located intree-ssa-loop.cc and is described by pass_ipa_oacc.
• IPA points-to analysis
  This is a tree-based points-to analysis pass. The idea behind this analyzer is to generate set constraints from the program, then solve the resulting constraints in order to generate the points-to sets. It is located in tree-ssa-structalias.cc and is described by pass_ipa_pta.
• IPA OpenACC kernels
  This is a pass group for processing OpenACC kernels regions. It is a subpass of the IPA OpenACC pass group that runs on offloaded functions containing OpenACC kernels loops. It is located intree-ssa-loop.cc and is described bypass_ipa_oacc_kernels.
• Target clone
  This is a pass for parsing functions with multiple target attributes. It is located in multiple_target.cc and is described bypass_target_clone.
• IPA auto profile
  This pass uses AutoFDO profiling data to annotate the control flow graph. It is located in auto-profile.cc and is described bypass_ipa_auto_profile.
• IPA tree profile
  This pass does profiling for all functions in the call graph. It calculates branch probabilities and basic block execution counts. It is located in tree-profile.cc and is described by pass_ipa_tree_profile.
• IPA free function summary
  This pass is a small IPA pass when argument small_p is true. It releases inline function summaries and call summaries. It is located in ipa-fnsummary.cc and is described bypass_ipa_free_free_fn_summary.
• IPA increase alignment
  This pass increases the alignment of global arrays to improve vectorization. It is located in tree-vectorizer.ccand is described by pass_ipa_increase_alignment.
• IPA transactional memory
  This pass is for transactional memory support. It is located in trans-mem.cc and is described bypass_ipa_tm.
• IPA lower emulated TLS
  This pass lowers thread-local storage (TLS) operations to emulation functions provided by libgcc. It is located in tree-emutls.cc and is described bypass_ipa_lower_emutls.