4 files changed, 59 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6235f5d..44ed9d2 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2005-06-16  Richard Henderson  <rth@redhat.com>
+
+	PR tree-opt/22022
+	* tree-complex.c (update_phi_components): Avoid no-op moves.
+
 2005-06-16  Joseph S. Myers  <joseph@codesourcery.com>
 
 	* Makefile.in (cc1-checksum.c): Use
diff --git a/gcc/testsuite/g++.dg/opt/complex2.C b/gcc/testsuite/g++.dg/opt/complex2.C
new file mode 100644
index 0000000..53fc7e9
--- /dev/null
+++ b/gcc/testsuite/g++.dg/opt/complex2.C
@@ -0,0 +1,24 @@
+// PR 22022
+// { dg-do compile }
+// { dg-options "-O2" }
+
+_Complex float f();
+_Complex float g();
+_Complex float h()throw();
+void i(_Complex float)throw();
+
+void j(void)
+{
+  _Complex float x = h();
+  try
+  {
+    try
+    {
+      x = f();
+    }catch (...)
+    {
+      x = g();
+    }
+  }catch(...){}
+  i(x);
+}
diff --git a/gcc/testsuite/g++.dg/opt/complex3.C b/gcc/testsuite/g++.dg/opt/complex3.C
new file mode 100644
index 0000000..9a3fdf3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/opt/complex3.C
@@ -0,0 +1,24 @@
+// PR 22022
+// { dg-do compile }
+// { dg-options "-O2" }
+
+_Complex float f();
+_Complex float g();
+_Complex float h()throw();
+void i(float)throw();
+
+float j(void)
+{
+  _Complex float x = h();
+  try
+  {
+    try
+    {
+      x = f();
+    }catch (...)
+    {
+      x += g();
+    }
+  }catch(...){}
+  i(__builtin_crealf(x)+__builtin_cimagf(x));
+}
diff --git a/gcc/tree-complex.c b/gcc/tree-complex.c
index a4c7329..a3470b1 100644
--- a/gcc/tree-complex.c
+++ b/gcc/tree-complex.c
@@ -577,6 +577,12 @@ update_phi_components (basic_block bb)
 	    tree arg = PHI_ARG_DEF (phi, i);
 	    tree r, i;
 
+	    /* Avoid no-op assignments.  This also prevents insertting stmts
+	       onto abnormal edges, assuming the PHI isn't already broken.  */
+	    if (TREE_CODE (arg) == SSA_NAME
+		&& SSA_NAME_VAR (arg) == SSA_NAME_VAR (lhs))
+	      continue;
+
 	    r = extract_component (NULL, arg, 0, false);
 	    i = extract_component (NULL, arg, 1, false);
 	    update_complex_components_on_edge (e, NULL, lhs, r, i);