• GCCProjects

GCC has many projects over the years, some have been completed, some are partially done, some have not been started and some need new owners because the developer left.

• Merge in ImprovementProjects and EasyHacks

• Also see GCC projects weg page

Active/Ongoing GCC projects

• ForgeExperiment

• Diagnostic Related Projects

  • libgdiagnostics

  • SARIF

  • HTMLDiagnostics

• Static Analyzer (-fanalyzer)

• Front-ends Projects

  • Rust Front End

  • Algol 68 Front End

  • Fortran

    • Object Oriented Programming in Fortran

• Target Library projects

  • libstdc++ todo list

• Aarch64GCCForWindows

• Loop Optimization Related Tasks

  • Automatic parallelization

  • Data_Dependence_Analysis

  • Tree_Vectorizer

    • Vectorization Related Tasks

    • Autovectorization_Enhancements

• AutoFDO

• Scalar and other optimization Projects

  • Final SRA

  • SubregTrackingRA

  • MemCpySetOpt

• Middle-end and Backend Cleanup Projects

  • LRAIsDefault: Removal of reload

  • Documenting GIMPLE canonical forms

  • PHIOpt-Match

• Function Specific Optimization (stage 4)

  • https://gcc.gnu.org/pipermail/gcc-patches/2025-October/696517.html

• OpenMP

• OpenACC

• kcfi

Projects that need owners

These are projects which had a start as a patch but needs more work and the developer dropped it for other work.

• Middle End Array Expressions

• Make C undefined overflow semantics explicit in the IL

• Graphite

• Gimple Back End

• replacelibibertywithgnulib

• Incremental compiler

• struct-reorg and Structure_Reorganization_Optimization

  • this was once in the GCC repo but since has been removed

• CLI Back-End and Front-End

  • Branch seems to be abandoned (in 2009)

• Transactional Memory

Projects have not started

• Loop Optimization Related Tasks

  • Loop_Fusion

  • Loop Fission

  • Loop Tiling

  • Loop Blocking

  • Tree_Linear_Loop_Transforms

• Middle-end and Backend Cleanup Projects

  • RemoveTER

  • ExpandCallsDirectly

  • Cleaning up GCC passes

  • simplemergephitocfgcleanup

• Boring GCC (boringcc)

• typesan

• memsan

• CFI

• ftime-trace

• Pass Activity Log

• Improvements to Atomics

• Improve GCC instruction selection

• Areas that can help speed up the compiler

• Make GCC more modular

• Parallelize GCC with Threads

Abandoned projects

Projects which was developed and then decided not to do it or superseded by others

• Thread Safety Annotations and Analysis

  • -fanalyzer and tsan replaced this?

• Mudflap_Pointer_Debugging

  • address sanitizer replaced it

• reload-v2

  • LRA replaced it

• SSACombine and Tree-Combiner

  • Replaced by MatchAndSimplify

• MILEPOST GCC - enabling research on machine-learning based self-tuning compilers

  • External project for this has been abandoned

• IMAforCxx

  • Replaced by LinkTimeOptimization

• Middle End Lisp Translator or MELT

  • External project for this has been abandoned

• GUPC

  • GUPC is only supported up with GCC 5.x
  • last UPC change was in 2022

Projects that need to be categorized

• EasyHacks

• Better Diagnostics

• Better Uninitialized Warnings

• C++ ABI Instrumentation

• Document the Middle-End Type System

• Function Adaptation

• gcc-in-cxx - porting gcc to compile as C++

• Interactive Compilation Interface

• Lightweight IPO -- LIPO

• Modeling Function Behavior for more aggressive optimizations across call sites

• Modulo Scheduling Related Tasks

• Pre-Parsed Headers

• SSA Register Pressure Reduction

• Python Front End

• Stdlib Performance Advisor

• GVN-PRE_for_loads

• GVN-PRE

Summer of code Projects

??? What to put here ??? ??? Completed ones will be below ??? SummerOfCode

Projects finished each version

GCC 16

• Function Specific Optimization (stage 3)

  • stage 3 was finished for aarch64 and riscv (and C support)
• Removal of pass_fold_builtins

• AutoFDO

  • aarch64 supported now

GCC 15

• SLP vectorizer only

• libgdiagnostics is included

• GCC diagnostic output as a HTML page

GCC 14

• BitIntSupport

• Rust Front End

  • Initial support was added

GCC 13

• hwasan for x86
• assume (C++20) attribute support
• Remove old EVRP code and only use ranger

• GCC output diagnostic as SARIF

GCC 12

• CC0 Transition

• __builtin_dynamic_object_size support

• Rename .c to .cc
• Strlen pass convert to ranger

GCC 11

• C++ Modules

• IPAmodref - new version

• hwasan
  • for aarch64

GCC 10

• GIT Conversion - Converting GCC's repository from SVN to GIT

• BPF Back End

• Ranger - On-demand range generation

  • Passes were converted later on

• Static Analyzer (-fanalyzer)

• OpenACC

• C++ Coroutines

GCC 9

• LoopVersioningForStride

GCC 8

• Cilk Plus was removed

• IEEE 128-bit floating point support for PowerPC

• LoopInterchange

• LoopUnrollAndJam

GCC 7

• Early Generation of Debug Information

GCC 6

• Gimple Front End

• Function Specific Optimization (stage 3 support for x86)

GCC 5

• OpenMP/OpenAcc Offloading

• Expression Simplification Language

• Just-In-Time Compilation (libgccjit.so)

• AutoFDO

  • x86_64 only

GCC 4.9

• ubsan

• OpenMP 4.0

• Cilk Plus merge into mainline

• Removed Mudflap_Pointer_Debugging

GCC 4.8

• LRA: reload replacement

• FunctionMultiVersioning

• C++ Conversion

• asan
• tsan
• aarch64 backend

• libatomic Atomics

• C11 Atomics

GCC 4.7

• Transactional Memory

• Only IRA - removal of old local and global RA

• OpenMP 3.1

• Atomics and C++11 Memory Model

GCC 4.6

• Constexpr

• Flattening Memory Reference Trees in the GIMPLE IL

• Split Stacks

  • x86_64 only

GCC 4.5

• Alias Improvements

• Compiler Plugins

• Link Time Optimization

• Tightening GCC's Memory Model

• Var Tracking Assignments for correct debug information

GCC 4.4

• GIMPLE tuples

• Function Specific Optimization (stage 1 and 2)

• OpenMP 3.0

• IRA - global/local RA replacement
  • added as an option

• Object Oriented Programming in Fortran

GCC 4.3

GCC_4.3_Release_Planning

• PointerPlus

• Top-Level_Libgcc_Migration

• mem-ssa

• Toplevel_libgcc

• variadic-templates

• TreeRepresentationChanges

• DataflowPorting Replace_backend_dataflow

• Automatic parallelization

GCC 4.2

GCC_4.2_Projects

• Response_Files

• Section_Anchor_Optimisations

• Decimal_Floating-Point

• New_tree_reassociation_pass

• Top-Level_Bootstrap

• Load_partial_redundancy_elimination

• OpenMP 2.5

• Sign_Extension_Removal

GCC 4.1

GCC_4.1_Projects

• New_C_Parser: New C recursive descent parser

• New_DECL_hierarchy

• Port of IBM Pro Police Stack Detector (SSP or -fstack-protector)

• Safe_Builtins: __builtin_object_size and *_chk functions

GCC 4.0

• edge_vector_project

• tree-ssa

  • Mudflap_Pointer_Debugging

• Visibility

GCC 3.4

• Using profile to drive optimizations

• New C++ recursive descent parser
• PCH

GCC 3.3

GCC 3.2

GCC 3.1

GCC 3.0