* tree-flow-inline.h (may_propagate_copy): Do not allow propagation of

	a constant for a virtual operand.

	* gcc.c-torture/compile/20040309-1.c: New test.


git-svn-id: https://gcc.gnu.org/svn/gcc/branches/tree-ssa-20020619-branch@79195 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 52 insertions, 4 deletions

diff --git a/gcc/ChangeLog.tree-ssa b/gcc/ChangeLog.tree-ssa
index 2cabc7aa0fc..f3feaecc112 100644
--- a/gcc/ChangeLog.tree-ssa
+++ b/gcc/ChangeLog.tree-ssa
@@ -1,3 +1,8 @@
+2004-03-09  Jeff Law  <law@redhat.com>
+
+	* tree-flow-inline.h (may_propagate_copy): Do not allow propagation of
+	a constant for a virtual operand.
+
 2004-03-08  Richard Henderson <rth@redhat.com>
 
 	* calls.c (initialize_argument_information): Add
diff --git a/gcc/testsuite/ChangeLog.tree-ssa b/gcc/testsuite/ChangeLog.tree-ssa
index 7af34094379..dbc9cd28bee 100644
--- a/gcc/testsuite/ChangeLog.tree-ssa
+++ b/gcc/testsuite/ChangeLog.tree-ssa
@@ -1,3 +1,7 @@
+2004-03-09  Jeff Law  <law@redhat.com>
+
+	* gcc.c-torture/compile/20040309-1.c: New test.
+
 2004-03-05  Jeff Law  <law@redhat.com>
 
 	* gcc.dg/tree-ssa/20040305-1.c: New test.
diff --git a/gcc/testsuite/gcc.c-torture/compile/20040309-1.c b/gcc/testsuite/gcc.c-torture/compile/20040309-1.c
new file mode 100644
index 00000000000..df8390f207b
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/20040309-1.c
@@ -0,0 +1,20 @@
+static const char default_tupleseps[] = ", \t";
+
+
+fubar (tupleseps)
+     const char *tupleseps;
+{
+  char *kp, *sp;
+  const char *septmp;
+  const char *tseplist;
+  tseplist = (tupleseps) ? tupleseps : default_tupleseps;
+  while (kp)
+    {
+      if (*tseplist)
+        septmp = tseplist;
+      bar (*septmp);
+      if (*tseplist)
+        if (*kp)
+          ;
+    }
+}
diff --git a/gcc/tree-flow-inline.h b/gcc/tree-flow-inline.h
index c48026000d8..3505b0c4f19 100644
--- a/gcc/tree-flow-inline.h
+++ b/gcc/tree-flow-inline.h
@@ -438,10 +438,29 @@ may_propagate_copy (tree dest, tree orig)
 	return false;
     }
 
-  /* We do not care about abnormal PHIs or user specified register
-     declarations for virtual operands.  */
-  if (! is_gimple_reg (dest))
-    return true;
+  /* If the destination is a SSA_NAME for a virtual operand, then we have
+     some special cases to handle.  */
+  if (TREE_CODE (dest) == SSA_NAME && !is_gimple_reg (dest))
+    {
+      /* If both operands are SSA_NAMEs referring to virtual operands, then
+	 we can always propagate.  */
+      if (TREE_CODE (orig) == SSA_NAME)
+	{
+	  if (!is_gimple_reg (orig))
+	    return true;
+
+#ifdef ENABLE_CHECKING
+	  /* If we have one real and one virtual operand, then something has
+	     gone terribly wrong.  */
+	  if (is_gimple_reg (orig))
+	    abort ();
+#endif
+	}
+
+      /* We have a "copy" from something like a constant into a virtual
+	 operand.  Reject these.  */
+      return false;
+    }
 
   return (!SSA_NAME_OCCURS_IN_ABNORMAL_PHI (dest)
 	  && (TREE_CODE (orig) != SSA_NAME