2009-01-18 Richard Guenther <rguenther@suse.de>

	PR tree-optimization/38819
	* tree-flow.h (operation_could_trap_helper_p): Declare.
	* tree-eh.c (operation_could_trap_helper_p): Export.
	* tree-ssa-sccvn.h (vn_nary_may_trap): Declare.
	* tree-ssa-sccvn.c (vn_nary_may_trap): New function.
	* tree-ssa-pre.c (insert_into_preds_of_block): Check if we
	are about to insert a possibly trapping instruction and fail
	in this case.

	* gcc.c-torture/execute/pr38819.c: New testcase.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@143485 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 47 insertions, 0 deletions

diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index e40681f9355..78af47ed5eb 100644
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -3072,3 +3072,50 @@ sort_vuses_heap (VEC (tree,heap) *vuses)
 	   sizeof (tree),
 	   operand_build_cmp);
 }
+
+
+/* Return true if the nary operation NARY may trap.  This is a copy
+   of stmt_could_throw_1_p adjusted to the SCCVN IL.  */
+
+bool
+vn_nary_may_trap (vn_nary_op_t nary)
+{
+  tree type;
+  tree rhs2;
+  bool honor_nans = false;
+  bool honor_snans = false;
+  bool fp_operation = false;
+  bool honor_trapv = false;
+  bool handled, ret;
+  unsigned i;
+
+  if (TREE_CODE_CLASS (nary->opcode) == tcc_comparison
+      || TREE_CODE_CLASS (nary->opcode) == tcc_unary
+      || TREE_CODE_CLASS (nary->opcode) == tcc_binary)
+    {
+      type = nary->type;
+      fp_operation = FLOAT_TYPE_P (type);
+      if (fp_operation)
+	{
+	  honor_nans = flag_trapping_math && !flag_finite_math_only;
+	  honor_snans = flag_signaling_nans != 0;
+	}
+      else if (INTEGRAL_TYPE_P (type)
+	       && TYPE_OVERFLOW_TRAPS (type))
+	honor_trapv = true;
+    }
+  rhs2 = nary->op[1];
+  ret = operation_could_trap_helper_p (nary->opcode, fp_operation,
+				       honor_trapv,
+				       honor_nans, honor_snans, rhs2,
+				       &handled);
+  if (handled
+      && ret)
+    return true;
+
+  for (i = 0; i < nary->length; ++i)
+    if (tree_could_trap_p (nary->op[i]))
+      return true;
+
+  return false;
+}