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-rw-r--r--gcc/ChangeLog5
-rw-r--r--gcc/testsuite/ChangeLog5
-rw-r--r--gcc/testsuite/gcc.dg/tree-ssa/pr57361.c9
-rw-r--r--gcc/tree-ssa-dse.c7
4 files changed, 26 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0b15431..ec3daf2 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2013-06-12 Marc Glisse <marc.glisse@inria.fr>
+
+ PR tree-optimization/57361
+ * tree-ssa-dse.c (dse_possible_dead_store_p): Handle self-assignment.
+
2013-06-12 Sofiane Naci <sofiane.naci@arm.com>
* config/aarch64/aarch64-simd.md (aarch64_combine<mode>): convert to split.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 187f2ef..dc29124 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2013-06-12 Marc Glisse <marc.glisse@inria.fr>
+
+ PR tree-optimization/57361
+ * gcc.dg/tree-ssa/pr57361.c: New file.
+
2013-06-12 Ramana Radhakrishnan <ramana.radhakrishnan@arm.com>
* gcc.target/arm/unaligned-memcpy-4.c (src, dst): Initialize
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr57361.c b/gcc/testsuite/gcc.dg/tree-ssa/pr57361.c
new file mode 100644
index 0000000..81f27b3
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr57361.c
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-dse1-details" } */
+
+struct A { int x; double y; };
+void f (struct A *a) {
+ *a = *a;
+}
+
+/* { dg-final { scan-tree-dump "Deleted dead store" "dse1"} } */
diff --git a/gcc/tree-ssa-dse.c b/gcc/tree-ssa-dse.c
index ad99ea9..39f47ab 100644
--- a/gcc/tree-ssa-dse.c
+++ b/gcc/tree-ssa-dse.c
@@ -84,6 +84,13 @@ dse_possible_dead_store_p (gimple stmt, gimple *use_stmt)
*use_stmt = NULL;
+ /* Self-assignments are zombies. */
+ if (operand_equal_p (gimple_assign_rhs1 (stmt), gimple_assign_lhs (stmt), 0))
+ {
+ *use_stmt = stmt;
+ return true;
+ }
+
/* Find the first dominated statement that clobbers (part of) the
memory stmt stores to with no intermediate statement that may use
part of the memory stmt stores. That is, find a store that may