This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
[PATCH, PR 55579] Make SRA keep candidated with only debug replacements
- From: Martin Jambor <mjambor at suse dot cz>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Cc: Jakub Jelinek <jakub at redhat dot com>
- Date: Fri, 4 Jan 2013 14:00:39 +0100
- Subject: [PATCH, PR 55579] Make SRA keep candidated with only debug replacements
Hi,
the patch below fixes PR 55579 by not disqualifying a candidate
variable when it does not have any real replacements but has
ones for debug statements only.
analyze_access_subtree has to return the same value regardless of
MAY_HAVE_DEBUG_STMTS or we get debug comparison errors. I also have a
patch that simply avoids disqualifying candidates with no replacements
which means we keep some information about it so that SRA can remove a
few more un-needed reads but I suppose that is stage1 material.
OK for trunk?
Thanks,
Martin
2013-01-03 Martin Jambor <mjambor@suse.cz>
PR debug/55579
* tree-sra.c (analyze_access_subtree): Return true also after
potentially creating a debug-only replacement.
testsuite/
* gcc.dg/tree-ssa/pr55579.c: New test.
Index: src/gcc/testsuite/gcc.dg/tree-ssa/pr55579.c
===================================================================
--- /dev/null
+++ src/gcc/testsuite/gcc.dg/tree-ssa/pr55579.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -g -fdump-tree-esra" } */
+
+struct S { int a; char b; char c; short d; };
+
+int
+foo (int x)
+{
+ struct S s = { x + 1, x + 2, x + 3, x + 4 };
+ char *p = &s.c;
+ return x;
+}
+
+/* { dg-final { scan-tree-dump "Created a debug-only replacement for s" "esra" } } */
Index: src/gcc/tree-sra.c
===================================================================
--- src.orig/gcc/tree-sra.c
+++ src/gcc/tree-sra.c
@@ -2197,20 +2197,25 @@ analyze_access_subtree (struct access *r
}
else
{
- if (MAY_HAVE_DEBUG_STMTS && allow_replacements
+ if (allow_replacements
&& scalar && !root->first_child
&& (root->grp_scalar_write || root->grp_assignment_write))
{
gcc_checking_assert (!root->grp_scalar_read
&& !root->grp_assignment_read);
- root->grp_to_be_debug_replaced = 1;
- if (dump_file && (dump_flags & TDF_DETAILS))
+ sth_created = true;
+ if (MAY_HAVE_DEBUG_STMTS)
{
- fprintf (dump_file, "Marking ");
- print_generic_expr (dump_file, root->base, 0);
- fprintf (dump_file, " offset: %u, size: %u ",
- (unsigned) root->offset, (unsigned) root->size);
- fprintf (dump_file, " to be replaced with debug statements.\n");
+ root->grp_to_be_debug_replaced = 1;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Marking ");
+ print_generic_expr (dump_file, root->base, 0);
+ fprintf (dump_file, " offset: %u, size: %u ",
+ (unsigned) root->offset, (unsigned) root->size);
+ fprintf (dump_file, " to be replaced with debug "
+ "statements.\n");
+ }
}
}
@@ -2220,17 +2225,11 @@ analyze_access_subtree (struct access *r
root->grp_total_scalarization = 0;
}
- if (sth_created
- && (!hole || root->grp_total_scalarization))
- {
- root->grp_covered = 1;
- return true;
- }
- if (root->grp_write || TREE_CODE (root->base) == PARM_DECL)
+ if (!hole || root->grp_total_scalarization)
+ root->grp_covered = 1;
+ else if (root->grp_write || TREE_CODE (root->base) == PARM_DECL)
root->grp_unscalarized_data = 1; /* not covered and written to */
- if (sth_created)
- return true;
- return false;
+ return sth_created;
}
/* Analyze all access trees linked by next_grp by the means of