[PATCH] Ensure matching types in debug stmts created by tree-sra.c (PR tree-optimization/55920)

[Jakub Jelinek]

Hi!

This patch fixes ICE on the attached testcase on ARM, where we ended up
creating invalid debug stmt, which had SImode var on the lhs, but BLKmode
MEM_REF on the rhs.  Fixed by matching (almost, with the build_ref_for_model
-> build_debug_ref_for_model change) what we do for normal stmt
modifications earlier.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2013-01-15  Jakub Jelinek  <ja...@redhat.com>

        PR tree-optimization/55920
        * tree-sra.c (sra_modify_assign): If for lacc->grp_to_be_debug_replaced
        there is non-useless type conversion needed from debug rhs to lhs,
        use build_debug_ref_for_model and/or VIEW_CONVERT_EXPR.

        * gcc.c-torture/compile/pr55920.c: New test.

--- gcc/tree-sra.c.jj   2013-01-11 09:02:55.000000000 +0100
+++ gcc/tree-sra.c      2013-01-15 12:52:01.161324202 +0100
@@ -3108,8 +3108,20 @@ sra_modify_assign (gimple *stmt, gimple_
 
   if (lacc && lacc->grp_to_be_debug_replaced)
     {
-      gimple ds = gimple_build_debug_bind (get_access_replacement (lacc),
-                                          unshare_expr (rhs), *stmt);
+      tree debug_lhs = get_access_replacement (lacc);
+      tree debug_rhs = unshare_expr (rhs);
+      if (!useless_type_conversion_p (TREE_TYPE (debug_lhs),
+                                     TREE_TYPE (debug_rhs)))
+       {
+         if (AGGREGATE_TYPE_P (TREE_TYPE (debug_rhs))
+             && !contains_vce_or_bfcref_p (debug_rhs))
+           debug_rhs = build_debug_ref_for_model (loc, debug_rhs, 0, lacc);
+         if (!useless_type_conversion_p (TREE_TYPE (debug_lhs),
+                                         TREE_TYPE (debug_rhs)))
+           debug_rhs = fold_build1_loc (loc, VIEW_CONVERT_EXPR,
+                                        TREE_TYPE (debug_lhs), debug_rhs);
+       }
+      gimple ds = gimple_build_debug_bind (debug_lhs, debug_rhs, *stmt);
       gsi_insert_before (gsi, ds, GSI_SAME_STMT);
     }
 
--- gcc/testsuite/gcc.c-torture/compile/pr55920.c.jj    2013-01-15 
12:58:01.782125163 +0100
+++ gcc/testsuite/gcc.c-torture/compile/pr55920.c       2013-01-15 
12:57:23.000000000 +0100
@@ -0,0 +1,16 @@
+/* PR tree-optimization/55920 */
+
+struct A { unsigned a; } __attribute__((packed));
+struct B { int b; unsigned char c[16]; };
+void bar (struct A);
+
+void
+foo (struct B *x)
+{
+  struct A a;
+  if (x->b)
+    __builtin_memcpy (&a, x->c, sizeof a);
+  else
+    a.a = 0;
+  bar (a);
+}

        Jakub