State purging only happens for SSA names, and locals of struct type aren't SSA names. Given e.g.: struct boxed { int value; }; extern struct boxed boxed_add (struct boxed a, struct boxed b); extern struct boxed boxed_mul (struct boxed a, struct boxed b); struct boxed test (struct boxed a, struct boxed b) { struct boxed result = boxed_add (boxed_mul (a, a), boxed_mul (b, b)); return result; } without optimization we have this gimple: struct boxed test (struct boxed a, struct boxed b) { struct boxed result; struct boxed D.1994; struct boxed D.1993; struct boxed D.1992; <bb 2> : D.1992 = boxed_mul (b, b); D.1993 = boxed_mul (a, a); result = boxed_add (D.1993, D.1992); D.1994 = result; result ={v} {CLOBBER(eol)}; <bb 3> : <L1>: return D.1994; } and this final exploded node: EN 11: preds: EN: 10 succs: callstring: [] after SN: 3 rmodel: stack depth: 1 frame (index 0): frame: ‘test’@1 clusters within frame: ‘test’@1 cluster for: <anonymous>: CONJURED(D.1992 = boxed_mul (b, b);, <anonymous>) cluster for: <anonymous>: CONJURED(D.1993 = boxed_mul (a, a);, <anonymous>) cluster for: <anonymous>: CONJURED(result = boxed_add (D.1993, D.1992);, result) cluster for: <anonymous>: CONJURED(result = boxed_add (D.1993, D.1992);, result) m_called_unknown_fn: TRUE constraint_manager: equiv classes: constraints: where the various <anonymous> are the values of the local temporaries of struct type, which ought to be purged; they don't matter anymore. Seen on linux kernel: drivers/gpu/drm/amd/display/dc/calcs/dce_calcs.c which amongst other things has: struct bw_fixed { int64_t value; }; with numerous calls to manipulate values; the states get bloated with bindings for temporaries that persist far longer than they are needed.

The master branch has been updated by David Malcolm <dmalcolm@gcc.gnu.org>: https://gcc.gnu.org/g:1c1daca1cdf7bc0156d57bb2b9083ee70c66b000 commit r12-7717-g1c1daca1cdf7bc0156d57bb2b9083ee70c66b000 Author: David Malcolm <dmalcolm@redhat.com> Date: Thu Mar 17 18:12:46 2022 -0400 analyzer: add tests of boxed values [PR104943] This patch adds various regression tests as preparatory work for purging irrelevant local decls from state (PR analyzer/104943) gcc/testsuite/ChangeLog: PR analyzer/104943 * gcc.dg/analyzer/boxed-malloc-1-29.c: New test. * gcc.dg/analyzer/boxed-malloc-1.c: New test. * gcc.dg/analyzer/taint-alloc-5.c: New test. * gcc.dg/analyzer/torture/boxed-int-1.c: New test. * gcc.dg/analyzer/torture/boxed-ptr-1.c: New test. Signed-off-by: David Malcolm <dmalcolm@redhat.com>

The master branch has been updated by David Malcolm <dmalcolm@gcc.gnu.org>: https://gcc.gnu.org/g:faacafd2306ad7ece721a79dedbb6e44e0d65bdb commit r12-7718-gfaacafd2306ad7ece721a79dedbb6e44e0d65bdb Author: David Malcolm <dmalcolm@redhat.com> Date: Tue Dec 7 19:22:47 2021 -0500 analyzer: extend state-purging to locals [PR104943] The existing analyzer code attempts to purge the state of SSA names where it can in order to minimize the size of program_state instances, and to increase the chances of being able to reuse exploded_node instances whilst exploring the user's code. PR analyzer/104943 identifies that we fail to purge state of local variables, based on behavior seen in PR analyzer/104954 when attempting to profile slow performance of -fanalyzer on a particular file in the Linux kernel, where that testcase has many temporary "boxed" values of structs containing ints, which are never cleaned up, leading to bloat of the program_state instances (specifically, of the store objects). This patch generalizes the state purging from just being on SSA names to also work on local variables. Doing so requires that we detect where addresses to a local variable (or within them) are taken; we assume that once a pointer has been taken, it's not longer safe to purge the value of that decl at any successor point within the function. Doing so speeds up the PR analyzer/104954 Linux kernel analyzer testcase from taking 254 seconds to "just" 186 seconds (and I have a followup patch in development that seems to further reduce this to 37 seconds). The patch may also help with scaling up taint-detection so that it can eventually be turned on by default, but we're not quite there (this is PR analyzer/103533). gcc/analyzer/ChangeLog: PR analyzer/104943 PR analyzer/104954 PR analyzer/103533 * analyzer.h (class state_purge_per_decl): New forward decl. * engine.cc (impl_run_checkers): Pass region_model_manager to state_purge_map ctor. * program-point.cc (function_point::final_stmt_p): New. (function_point::get_next): New. * program-point.h (function_point::final_stmt_p): New decl. (function_point::get_next): New decl. * program-state.cc (program_state::prune_for_point): Generalize to purge local decls as well as SSA names. (program_state::can_purge_base_region_p): New. * program-state.h (program_state::can_purge_base_region_p): New decl. * region-model.cc (struct append_ssa_names_cb_data): Rename to... (struct append_regions_cb_data): ...this. (region_model::get_ssa_name_regions_for_current_frame): Rename to... (region_model::get_regions_for_current_frame): ...this, updating for other renamings. (region_model::append_ssa_names_cb): Rename to... (region_model::append_regions_cb): ...this, and drop the requirement that the subregion be a SSA name. * region-model.h (struct append_ssa_names_cb_data): Rename decl to... (struct append_regions_cb_data): ...this. (region_model::get_ssa_name_regions_for_current_frame): Rename decl to... (region_model::get_regions_for_current_frame): ...this. (region_model::append_ssa_names_cb): Rename decl to... (region_model::append_regions_cb): ...this. * state-purge.cc: Include "tristate.h", "selftest.h", "analyzer/store.h", "analyzer/region-model.h", and "gimple-walk.h". (get_candidate_for_purging): New. (class gimple_op_visitor): New. (my_load_cb): New. (my_store_cb): New. (my_addr_cb): New. (state_purge_map::state_purge_map): Add "mgr" param. Update for renamings. Find uses of local variables. (state_purge_map::~state_purge_map): Update for renaming of m_map to m_ssa_map. Clean up m_decl_map. (state_purge_map::get_or_create_data_for_decl): New. (state_purge_per_ssa_name::state_purge_per_ssa_name): Update for inheriting from state_purge_per_tree. (state_purge_per_ssa_name::add_to_worklist): Likewise. (state_purge_per_decl::state_purge_per_decl): New. (state_purge_per_decl::add_needed_at): New. (state_purge_per_decl::add_pointed_to_at): New. (state_purge_per_decl::process_worklists): New. (state_purge_per_decl::add_to_worklist): New. (same_binding_p): New. (fully_overwrites_p): New. (state_purge_per_decl::process_point_backwards): New. (state_purge_per_decl::process_point_forwards): New. (state_purge_per_decl::needed_at_point_p): New. (state_purge_annotator::print_needed): Generalize to print local decls as well as SSA names. * state-purge.h (class state_purge_map): Update leading comment. (state_purge_map::map_t): Rename to... (state_purge_map::ssa_map_t): ...this. (state_purge_map::iterator): Rename to... (state_purge_map::ssa_iterator): ...this. (state_purge_map::decl_map_t): New typedef. (state_purge_map::decl_iterator): New typedef. (state_purge_map::state_purge_map): Add "mgr" param. (state_purge_map::get_data_for_ssa_name): Update for renaming. (state_purge_map::get_any_data_for_decl): New. (state_purge_map::get_or_create_data_for_decl): New decl. (state_purge_map::begin): Rename to... (state_purge_map::begin_ssas): ...this. (state_purge_map::end): Rename to... (state_purge_map::end_ssa): ...this. (state_purge_map::begin_decls): New. (state_purge_map::end_decls): New. (state_purge_map::m_map): Rename to... (state_purge_map::m_ssa_map): ...this. (state_purge_map::m_decl_map): New field. (class state_purge_per_tree): New class. (class state_purge_per_ssa_name): Inherit from state_purge_per_tree. (state_purge_per_ssa_name::get_function): Move to base class. (state_purge_per_ssa_name::point_set_t): Likewise. (state_purge_per_ssa_name::m_fun): Likewise. (class state_purge_per_decl): New. gcc/testsuite/ChangeLog: PR analyzer/104943 PR analyzer/104954 PR analyzer/103533 * gcc.dg/analyzer/torture/boxed-ptr-1.c: Update expected number of exploded nodes to reflect improvements in state purging. Signed-off-by: David Malcolm <dmalcolm@redhat.com>

Should be fixed by the above commit.