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| author | Richard Biener <rguenther@suse.de> | 2023-01-24 10:49:18 +0100 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2023-01-24 15:29:17 +0100 |
| commit | f31fa9ea35ebcf221a2abaacba5511225f5d036e (patch) | |
| tree | 0e7da00770611f268fca937e237226cd166694f4 /gcc | |
| parent | 9f0cb3368af735e95776769c4f28fa9cbb60eaf8 (diff) | |
| download | gcc-f31fa9ea35ebcf221a2abaacba5511225f5d036e.zip gcc-f31fa9ea35ebcf221a2abaacba5511225f5d036e.tar.gz gcc-f31fa9ea35ebcf221a2abaacba5511225f5d036e.tar.bz2 | |
tree-optimization/108500 - avoid useless fast-query compute in CFG cleanup
CFG cleanup computes dominators before the loop over blocks looking
for merging opportunities. That computes also the fast-query DFS
numbers but that's a bit pointless since any CFG cleanup will invalidate
them immediately (they are re-computed before fixing up loops).
The following avoids this and fixes the SIGSEGV due to the deep
recursion in assign_dfs_numbers after inlining very many small
functions.
PR tree-optimization/108500
* dominance.h (calculate_dominance_info): Add parameter
to indicate fast-query compute, defaulted to true.
* dominance.cc (calculate_dominance_info): Honor
fast-query compute parameter.
* tree-cfgcleanup.cc (cleanup_tree_cfg_noloop): Do
not compute the dominator fast-query DFS numbers.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/dominance.cc | 9 | ||||
| -rw-r--r-- | gcc/dominance.h | 2 | ||||
| -rw-r--r-- | gcc/tree-cfgcleanup.cc | 6 |
3 files changed, 11 insertions, 6 deletions
diff --git a/gcc/dominance.cc b/gcc/dominance.cc index 13d5498..099b8fd 100644 --- a/gcc/dominance.cc +++ b/gcc/dominance.cc @@ -705,10 +705,12 @@ compute_dom_fast_query_in_region (enum cdi_direction dir, } /* The main entry point into this module. DIR is set depending on whether - we want to compute dominators or postdominators. */ + we want to compute dominators or postdominators. If COMPUTE_FAST_QUERY + is false then the DFS numbers allowing for a O(1) dominance query + are not computed. */ void -calculate_dominance_info (cdi_direction dir) +calculate_dominance_info (cdi_direction dir, bool compute_fast_query) { unsigned int dir_index = dom_convert_dir_to_idx (dir); @@ -745,7 +747,8 @@ calculate_dominance_info (cdi_direction dir) else checking_verify_dominators (dir); - compute_dom_fast_query (dir); + if (compute_fast_query) + compute_dom_fast_query (dir); timevar_pop (TV_DOMINANCE); } diff --git a/gcc/dominance.h b/gcc/dominance.h index abdcf76..3c5a345 100644 --- a/gcc/dominance.h +++ b/gcc/dominance.h @@ -35,7 +35,7 @@ enum dom_state DOM_OK /* Everything is ok. */ }; -extern void calculate_dominance_info (enum cdi_direction); +extern void calculate_dominance_info (enum cdi_direction, bool = true); extern void calculate_dominance_info_for_region (enum cdi_direction, vec<basic_block>); extern void free_dominance_info (function *, enum cdi_direction); diff --git a/gcc/tree-cfgcleanup.cc b/gcc/tree-cfgcleanup.cc index ca0cb63..64ff16f 100644 --- a/gcc/tree-cfgcleanup.cc +++ b/gcc/tree-cfgcleanup.cc @@ -1106,9 +1106,11 @@ cleanup_tree_cfg_noloop (unsigned ssa_update_flags) timevar_push (TV_TREE_CLEANUP_CFG); } - /* Compute dominator info which we need for the iterative process below. */ + /* Compute dominator info which we need for the iterative process below. + Avoid computing the fast query DFS numbers since any block merging + done will invalidate them anyway. */ if (!dom_info_available_p (CDI_DOMINATORS)) - calculate_dominance_info (CDI_DOMINATORS); + calculate_dominance_info (CDI_DOMINATORS, false); else checking_verify_dominators (CDI_DOMINATORS); |