[gcc r13-8068] Fix ICE in vectorizable_nonlinear_induction with bitfield.

[gcc r13-8068] Fix ICE in vectorizable_nonlinear_induction with bitfield.

[hongtao Liu]

https://gcc.gnu.org/g:ed73ad337739a4244e8040d19b6e567c4101b58a

commit r13-8068-ged73ad337739a4244e8040d19b6e567c4101b58a
Author: liuhongt <hongtao.liu@intel.com>
Date:   Mon Nov 13 17:56:49 2023 +0800

    Fix ICE in vectorizable_nonlinear_induction with bitfield.
    
     if (TREE_CODE (init_expr) == INTEGER_CST)
        init_expr = fold_convert (TREE_TYPE (vectype), init_expr);
      else
        gcc_assert (tree_nop_conversion_p (TREE_TYPE (vectype),
                                           TREE_TYPE (init_expr)));
    
    and init_expr is a 24 bit integer type while vectype has 32bit components.
    
    The "fix" is to bail out instead of asserting.
    
    gcc/ChangeLog:
    
            PR tree-optimization/112496
            * tree-vect-loop.cc (vectorizable_nonlinear_induction): Return
            false when !tree_nop_conversion_p (TREE_TYPE (vectype),
            TREE_TYPE (init_expr)).
    
    gcc/testsuite/ChangeLog:
    
            * gcc.target/i386/pr112496.c: New test.
    
    (cherry picked from commit f28306b4fd309b579c8a4a5bf2f1b24fa40f8f7f)

Diff:
---
 gcc/testsuite/gcc.target/i386/pr112496.c |  7 +++++++
 gcc/tree-vect-loop.cc                    | 13 ++++++++++---
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/gcc/testsuite/gcc.target/i386/pr112496.c b/gcc/testsuite/gcc.target/i386/pr112496.c
new file mode 100644
index 00000000000..c478fda9cce
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr112496.c
@@ -0,0 +1,7 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+struct T { int x : 24; } v;
+void f1(int x) {
+  while (v.x - ((v.x <<= 1) - v.x)) ;
+}
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index a3cf0849b0c..d54c839779a 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -8929,9 +8929,16 @@ vectorizable_nonlinear_induction (loop_vec_info loop_vinfo,
 
   if (TREE_CODE (init_expr) == INTEGER_CST)
     init_expr = fold_convert (TREE_TYPE (vectype), init_expr);
-  else
-    gcc_assert (tree_nop_conversion_p (TREE_TYPE (vectype),
-				       TREE_TYPE (init_expr)));
+  else if (!tree_nop_conversion_p (TREE_TYPE (vectype), TREE_TYPE (init_expr)))
+    {
+      /* INIT_EXPR could be a bit_field, bail out for such case.  */
+      if (dump_enabled_p ())
+	dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
+			 "nonlinear induction vectorization failed:"
+			 " component type of vectype is not a nop conversion"
+			 " from type of init_expr.\n");
+      return false;
+    }
 
   switch (induction_type)
     {