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| author | Matthew Beliveau <mbelivea@redhat.com> | 2019-08-20 13:23:01 +0000 |
|---|---|---|
| committer | Matthew Beliveau <mbelivea@gcc.gnu.org> | 2019-08-20 13:23:01 +0000 |
| commit | 529f304811542ca34030b0dc0a7621503998da66 (patch) | |
| tree | 72fd99909e6b1d188a712b0a3d3b74399164ca7e /gcc/tree-ssa-dse.c | |
| parent | 00f7060a2db60e6fe7066bf65244909dc7693d19 (diff) | |
| download | gcc-529f304811542ca34030b0dc0a7621503998da66.zip gcc-529f304811542ca34030b0dc0a7621503998da66.tar.gz gcc-529f304811542ca34030b0dc0a7621503998da66.tar.bz2 | |
tree-ssa-dse.c (dse_optimize_redundant_stores): Improved check to catch more redundant zero initialization cases.
2019-08-19 Matthew Beliveau <mbelivea@redhat.com>
* tree-ssa-dse.c (dse_optimize_redundant_stores): Improved check to
catch more redundant zero initialization cases.
(dse_dom_walker::dse_optimize_stmt): Likewise.
From-SVN: r274749
Diffstat (limited to 'gcc/tree-ssa-dse.c')
| -rw-r--r-- | gcc/tree-ssa-dse.c | 22 |
1 files changed, 7 insertions, 15 deletions
diff --git a/gcc/tree-ssa-dse.c b/gcc/tree-ssa-dse.c index 5b7c4fc..ba67884 100644 --- a/gcc/tree-ssa-dse.c +++ b/gcc/tree-ssa-dse.c @@ -628,11 +628,8 @@ dse_optimize_redundant_stores (gimple *stmt) tree fndecl; if ((is_gimple_assign (use_stmt) && gimple_vdef (use_stmt) - && ((gimple_assign_rhs_code (use_stmt) == CONSTRUCTOR - && CONSTRUCTOR_NELTS (gimple_assign_rhs1 (use_stmt)) == 0 - && !gimple_clobber_p (stmt)) - || (gimple_assign_rhs_code (use_stmt) == INTEGER_CST - && integer_zerop (gimple_assign_rhs1 (use_stmt))))) + && (gimple_assign_single_p (use_stmt) + && initializer_zerop (gimple_assign_rhs1 (use_stmt)))) || (gimple_call_builtin_p (use_stmt, BUILT_IN_NORMAL) && (fndecl = gimple_call_fndecl (use_stmt)) != NULL && (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_MEMSET @@ -1027,16 +1024,11 @@ dse_dom_walker::dse_optimize_stmt (gimple_stmt_iterator *gsi) { bool by_clobber_p = false; - /* First see if this store is a CONSTRUCTOR and if there - are subsequent CONSTRUCTOR stores which are totally - subsumed by this statement. If so remove the subsequent - CONSTRUCTOR store. - - This will tend to make fewer calls into memset with longer - arguments. */ - if (gimple_assign_rhs_code (stmt) == CONSTRUCTOR - && CONSTRUCTOR_NELTS (gimple_assign_rhs1 (stmt)) == 0 - && !gimple_clobber_p (stmt)) + /* Check if this statement stores zero to a memory location, + and if there is a subsequent store of zero to the same + memory location. If so, remove the subsequent store. */ + if (gimple_assign_single_p (stmt) + && initializer_zerop (gimple_assign_rhs1 (stmt))) dse_optimize_redundant_stores (stmt); /* Self-assignments are zombies. */ |