re PR tree-optimization/37056 (ICE in build2_stat, at tree.c:3257)

2008-08-08  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/37056
	* gimple.h (gimple_assign_rhs_class): New helper function.
	* tree-ssa-loop-niter.c (get_val_for): Fix tuplification, handle
	unary operations properly.

	* gcc.c-torture/compile/pr37056.c: New testcase.

From-SVN: r138865

5 files changed, 73 insertions, 26 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f3e43e4..f3ba567 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2008-08-08  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/37056
+	* gimple.h (gimple_assign_rhs_class): New helper function.
+	* tree-ssa-loop-niter.c (get_val_for): Fix tuplification, handle
+	unary operations properly.
+
 2008-08-07  Jan Hubicka  <jh@suse.cz>
 
 	* i386.h (ix86_size_cost): Declare.
diff --git a/gcc/gimple.h b/gcc/gimple.h
index 0c11f3e..f32600d 100644
--- a/gcc/gimple.h
+++ b/gcc/gimple.h
@@ -1834,6 +1834,17 @@ gimple_assign_set_rhs_code (gimple s, enum tree_code code)
 }
 
 
+/* Return the gimple rhs class of the code of the expression computed on
+   the rhs of assignment statement GS.
+   This will never return GIMPLE_INVALID_RHS.  */
+
+static inline enum gimple_rhs_class
+gimple_assign_rhs_class (const_gimple gs)
+{
+  return get_gimple_rhs_class (gimple_assign_rhs_code (gs));
+}
+
+
 /* Return true if S is a type-cast assignment.  */
 
 static inline bool
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 356cc95..d930e38 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2008-08-08  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/37056
+	* gcc.c-torture/compile/pr37056.c: New testcase.
+
 2008-08-07  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
 	* gcc.dg/Wcxx-compat-2.c: Check for bool/_Bool.
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr37056.c b/gcc/testsuite/gcc.c-torture/compile/pr37056.c
new file mode 100644
index 0000000..f9285e2
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr37056.c
@@ -0,0 +1,28 @@
+extern void abort (void);
+
+static union {
+    char buf[12 * sizeof (long long)];
+} u;
+
+int main ()
+{
+  int off, len, i;
+  char *p, *q;
+
+  for (off = 0; off < (sizeof (long long)); off++)
+    for (len = 1; len < (10 * sizeof (long long)); len++)
+      {
+	for (i = 0; i < (12 * sizeof (long long)); i++)
+	  u.buf[i] = 'a';
+	p = (__extension__ (__builtin_constant_p ('\0') && ('\0') == '\0'
+			    ? ({void *__s = (u.buf + off); __s;})
+			    : __builtin_memset (u.buf + off, '\0', len)));
+	if (p != u.buf + off)
+	  abort ();
+	for (i = 0; i < off; i++, q++)
+	  if (*q != 'a')
+	    abort ();
+      }
+  return 0;
+}
+
diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c
index 1d0605e..b8247a0 100644
--- a/gcc/tree-ssa-loop-niter.c
+++ b/gcc/tree-ssa-loop-niter.c
@@ -2034,7 +2034,6 @@ static tree
 get_val_for (tree x, tree base)
 {
   gimple stmt;
-  tree nx, val, retval, rhs1, rhs2;
 
   gcc_assert (is_gimple_min_invariant (base));
 
@@ -2050,33 +2049,30 @@ get_val_for (tree x, tree base)
   /* STMT must be either an assignment of a single SSA name or an
      expression involving an SSA name and a constant.  Try to fold that
      expression using the value for the SSA name.  */
-  rhs1 = gimple_assign_rhs1 (stmt);
-  rhs2 = gimple_assign_rhs2 (stmt);
-  if (TREE_CODE (rhs1) == SSA_NAME)
-    nx = rhs1;
-  else if (rhs2 && TREE_CODE (rhs2) == SSA_NAME)
-    nx = rhs2;
-  else
-    gcc_unreachable ();
-
-  /* NX is now the SSA name for which we want to discover the base value.  */
-  val = get_val_for (nx, base);
-  if (rhs2)
-    {
-      /* If this is a binary expression, fold it.  If folding is
-	 not possible, return a tree expression with the RHS of STMT.  */
-      rhs1 = (nx == rhs1) ? val : rhs1;
-      rhs2 = (nx == rhs2) ? val : rhs2;
-      retval = fold_binary (gimple_assign_rhs_code (stmt),
-			    gimple_expr_type (stmt), rhs1, rhs2);
-      if (retval == NULL_TREE)
-	retval= build2 (gimple_assign_rhs_code (stmt),
-		        gimple_expr_type (stmt), rhs1, rhs2);
+  if (gimple_assign_ssa_name_copy_p (stmt))
+    return get_val_for (gimple_assign_rhs1 (stmt), base);
+  else if (gimple_assign_rhs_class (stmt) == GIMPLE_UNARY_RHS
+	   && TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME)
+    {
+      return fold_build1 (gimple_assign_rhs_code (stmt),
+			  gimple_expr_type (stmt),
+			  get_val_for (gimple_assign_rhs1 (stmt), base));
+    }
+  else if (gimple_assign_rhs_class (stmt) == GIMPLE_BINARY_RHS)
+    {
+      tree rhs1 = gimple_assign_rhs1 (stmt);
+      tree rhs2 = gimple_assign_rhs2 (stmt);
+      if (TREE_CODE (rhs1) == SSA_NAME)
+	rhs1 = get_val_for (rhs1, base);
+      else if (TREE_CODE (rhs2) == SSA_NAME)
+	rhs2 = get_val_for (rhs2, base);
+      else
+	gcc_unreachable ();
+      return fold_build2 (gimple_assign_rhs_code (stmt),
+			  gimple_expr_type (stmt), rhs1, rhs2);
     }
   else
-    retval = val;
-      
-  return retval;
+    gcc_unreachable ();
 }