[PATCH] Fix PR80167

[Richard Biener]

Seems we have simply forgotten about the case of replacing with a 
default-def.

Bootstrapped / tested on x86_64-unknown-linux-gnu, applied.

Richard.

2017-03-24  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/80167
        * graphite-isl-ast-to-gimple.c
        (translate_isl_ast_to_gimple::is_valid_rename): Handle default-defs
        properly.
        (translate_isl_ast_to_gimple::get_rename): Likewise.

        * gcc.dg/graphite/pr80167.c: New testcase.

Index: gcc/graphite-isl-ast-to-gimple.c
===================================================================
*** gcc/graphite-isl-ast-to-gimple.c    (revision 246437)
--- gcc/graphite-isl-ast-to-gimple.c    (working copy)
*************** bool translate_isl_ast_to_gimple::
*** 1123,1128 ****
--- 1123,1131 ----
  is_valid_rename (tree rename, basic_block def_bb, basic_block use_bb,
                 phi_node_kind phi_kind, tree old_name, basic_block old_bb) 
const
  {
+   if (SSA_NAME_IS_DEFAULT_DEF (rename))
+     return true;
+ 
    /* The def of the rename must either dominate the uses or come from a
       back-edge.  Also the def must respect the loop closed ssa form.  */
    if (!is_loop_closed_ssa_use (use_bb, rename))
*************** get_rename (basic_block new_bb, tree old
*** 1178,1183 ****
--- 1181,1187 ----
          basic_block bb = gimple_bb (SSA_NAME_DEF_STMT (rename));
          if (is_valid_rename (rename, bb, new_bb, phi_kind, old_name, old_bb)
              && (phi_kind == close_phi
+                 || ! bb
                  || flow_bb_inside_loop_p (bb->loop_father, new_bb)))
            return rename;
          return NULL_TREE;
Index: gcc/testsuite/gcc.dg/graphite/pr80167.c
===================================================================
*** gcc/testsuite/gcc.dg/graphite/pr80167.c     (nonexistent)
--- gcc/testsuite/gcc.dg/graphite/pr80167.c     (working copy)
***************
*** 0 ****
--- 1,24 ----
+ /* { dg-do compile } */
+ /* { dg-options "-O2 -floop-nest-optimize" } */
+ 
+ typedef struct
+ {
+   short a;
+   short b;
+   short c;
+ } d;
+ extern d e[];
+ int f[8];
+ void
+ g (d *i)
+ {
+   int h = 0;
+   for (; h < 28; h++)
+     e[h].a = e[h].b = i[h].a;
+   h = 0;
+   for (; h < 8; h++)
+     f[h] = i[h].b + i[h].c;
+   h = 0;
+   for (; h < 8; h++)
+     f[h] = i[h].b;
+ }