[PATCH] Fix PR83277

[PATCH] Fix PR83277

[Richard Biener]

The following fixes a code-gen error in GRAPHITE.  liveout handling
is still somewhat flaky and the easiest fix is to force code generation
of defs where ISL scheduled them (rather than at the PHI edge src).

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

Richard.

2017-12-05  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/83277
	* graphite-isl-ast-to-gimple.c (should_copy_to_new_region): Make sure
	to code-gen liveout vars.

	* gcc.dg/graphite/pr83277.c: New testcase.

Index: gcc/graphite-isl-ast-to-gimple.c
===================================================================
--- gcc/graphite-isl-ast-to-gimple.c	(revision 255402)
+++ gcc/graphite-isl-ast-to-gimple.c	(working copy)
@@ -1137,8 +1137,10 @@ should_copy_to_new_region (gimple *stmt,
   if (is_gimple_assign (stmt)
       && (lhs = gimple_assign_lhs (stmt))
       && TREE_CODE (lhs) == SSA_NAME
-      && is_gimple_reg (lhs)
-      && scev_analyzable_p (lhs, region->region))
+      && scev_analyzable_p (lhs, region->region)
+      /* But to code-generate liveouts - liveout PHI generation is
+         in generic sese.c code that cannot do code generation.  */
+      && ! bitmap_bit_p (region->liveout, SSA_NAME_VERSION (lhs)))
     return false;
 
   return true;
Index: gcc/testsuite/gcc.dg/graphite/pr83277.c
===================================================================
--- gcc/testsuite/gcc.dg/graphite/pr83277.c	(nonexistent)
+++ gcc/testsuite/gcc.dg/graphite/pr83277.c	(working copy)
@@ -0,0 +1,52 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -floop-nest-optimize" } */
+
+int rk, si = 0;
+int jr[2];
+
+int
+wv (signed char n8)
+{
+  const int tw = 8;
+  int xq[tw];
+  int bj, pu = 0;
+
+  for (bj = 0; bj < tw; ++bj)
+    xq[bj] = 0;
+
+  bj = 0;
+  while (bj < 1)
+    {
+      int gs = n8 ^ 128;
+
+      if (gs != 0)
+	{
+	  int u7[3];
+
+	  while (bj < 2)
+	    {
+	      u7[bj] = 0;
+	      ++bj;
+	    }
+
+	  jr[0] = u7[0];
+	  rk = xq[0];
+	  pu = n8;
+
+	  if (si != 0)
+	    return si;
+	}
+    }
+
+  return pu;
+}
+
+int
+main (void)
+{
+  signed char ax = 1;
+
+  if (wv (ax) != ax)
+    __builtin_abort ();
+  return 0;
+}