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| author | Richard Guenther <rguenther@suse.de> | 2010-10-13 13:03:31 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2010-10-13 13:03:31 +0000 |
| commit | 71d61348020eedc3d89e4c877ad714cbb2954792 (patch) | |
| tree | 1fbb62b9afc53835c17dfb33351b1fa61122bfce /gcc/tree-ssa-dse.c | |
| parent | 9827eb57a33462935e8d55d7e49f5ab4b16b887c (diff) | |
| download | gcc-71d61348020eedc3d89e4c877ad714cbb2954792.tar.gz | |
re PR tree-optimization/45970 (tree DSE misses many obvious dead stores)
2010-10-13 Richard Guenther <rguenther@suse.de>
PR tree-optimization/45970
* tree-ssa-alias.h (stmt_kills_ref_p): Declare.
* tree-ssa-alias.c (stmt_kills_ref_p_1): New function.
(stmt_kills_ref_p): Likewise.
* tree-ssa-dse.c (dse_optimize_stmt): Use it.
* gcc.dg/tree-ssa/ssa-dse-13.c: New testcase.
From-SVN: r165422
Diffstat (limited to 'gcc/tree-ssa-dse.c')
| -rw-r--r-- | gcc/tree-ssa-dse.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/gcc/tree-ssa-dse.c b/gcc/tree-ssa-dse.c index be440c9b657..80c2622c9dc 100644 --- a/gcc/tree-ssa-dse.c +++ b/gcc/tree-ssa-dse.c @@ -301,8 +301,9 @@ dse_optimize_stmt (struct dse_global_data *dse_gd, virtual uses from stmt and the stmt which stores to that same memory location, then we may have found redundant store. */ if (bitmap_bit_p (dse_gd->stores, get_stmt_uid (use_stmt)) - && operand_equal_p (gimple_assign_lhs (stmt), - gimple_assign_lhs (use_stmt), 0)) + && (operand_equal_p (gimple_assign_lhs (stmt), + gimple_assign_lhs (use_stmt), 0) + || stmt_kills_ref_p (use_stmt, gimple_assign_lhs (stmt)))) { /* If use_stmt is or might be a nop assignment, e.g. for struct { ... } S a, b, *p; ... |