[PATCH] Clamp vec_perm_expr index in simplify_bitfield_ref to avoid ICE.

[liuhongt via Gcc-patches]

Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}
Ok for trunk?

gcc/ChangeLog:

        PR tree-optimization/105591
        * tree-ssa-forwprop.cc (simplify_bitfield_ref): Clamp
        vec_perm_expr index.

gcc/testsuite/ChangeLog:

        * gcc.dg/pr105591.c: New test.
---
 gcc/testsuite/gcc.dg/pr105591.c | 12 ++++++++++++
 gcc/tree-ssa-forwprop.cc        | 13 ++++++++-----
 2 files changed, 20 insertions(+), 5 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/pr105591.c

diff --git a/gcc/testsuite/gcc.dg/pr105591.c b/gcc/testsuite/gcc.dg/pr105591.c
new file mode 100644
index 00000000000..9554c42e2f4
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr105591.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-Wno-psabi -O" } */
+/* { dg-additional-options "-mavx" { target x86_64-*-* i?86-*-* } } */
+typedef unsigned long long __attribute__((__vector_size__ (16))) U;
+typedef unsigned long long __attribute__((__vector_size__ (32))) V;
+
+V
+foo (U u)
+{
+  U x = __builtin_shuffle (u, (U) { 0xBE2ED0AB630B33FE });
+  return __builtin_shufflevector (u, x, 2, 1, 0, 3);
+}
diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index 48cab5844e0..7da3f80af10 100644
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -2381,23 +2381,26 @@ simplify_bitfield_ref (gimple_stmt_iterator *gsi)
 
   /* One element.  */
   if (known_eq (size, elem_size))
-    idx = TREE_INT_CST_LOW (VECTOR_CST_ELT (m, idx));
+    idx = TREE_INT_CST_LOW (VECTOR_CST_ELT (m, idx)) % (2 * nelts);
   else
     {
       unsigned HOST_WIDE_INT nelts_op;
       if (!constant_multiple_p (size, elem_size, &nelts_op)
          || !pow2p_hwi (nelts_op))
        return false;
-      unsigned start = TREE_INT_CST_LOW (vector_cst_elt (m, idx));
-      unsigned end = TREE_INT_CST_LOW (vector_cst_elt (m, idx + nelts_op - 1));
+      /* Clamp vec_perm_expr index.  */
+      unsigned start = TREE_INT_CST_LOW (vector_cst_elt (m, idx)) % (2 * 
nelts);
+      unsigned end = TREE_INT_CST_LOW (vector_cst_elt (m, idx + nelts_op - 1))
+                    % (2 * nelts);
       /* Be in the same vector.  */
       if ((start < nelts) != (end < nelts))
        return false;
       for (unsigned HOST_WIDE_INT i = 1; i != nelts_op; i++)
        {
          /* Continuous area.  */
-         if (TREE_INT_CST_LOW (vector_cst_elt (m, idx + i)) - 1
-             != TREE_INT_CST_LOW (vector_cst_elt (m, idx + i - 1)))
+         if (TREE_INT_CST_LOW (vector_cst_elt (m, idx + i)) % (2 * nelts) - 1
+             != TREE_INT_CST_LOW (vector_cst_elt (m, idx + i - 1))
+                % (2 * nelts))
            return false;
        }
       /* Alignment not worse than before.  */
-- 
2.18.1