[PR 70884] Constant pool SRA fix

2016-05-20  Martin Jambor  <mjambor@suse.cz>

	PR tree-optimization/70884
	* tree-sra.c (initialize_constant_pool_replacements): Do not check
	should_scalarize_away_bitmap and cannot_scalarize_away_bitmap bits.
	(sort_and_splice_var_accesses): Do not consider multiple scalar reads
	of constant pool data as a reason for scalarization.

testsuite/
	* gcc.dg/tree-ssa/pr70919.c: New test.

From-SVN: r236544

4 files changed, 86 insertions, 27 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8d6d3c4..dc38a17 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2016-05-20  Martin Jambor  <mjambor@suse.cz>
+
+	PR tree-optimization/70884
+	* tree-sra.c (initialize_constant_pool_replacements): Do not check
+	should_scalarize_away_bitmap and cannot_scalarize_away_bitmap bits.
+	(sort_and_splice_var_accesses): Do not consider multiple scalar reads
+	of constant pool data as a reason for scalarization.
+
 2016-05-20  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* config/arm/arm.c (arm_expand_prologue): Set the stack usage to 0
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index cdb5fea..b4ae113 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-05-20  Martin Jambor  <mjambor@suse.cz>
+
+	PR tree-optimization/70884
+	* gcc.dg/tree-ssa/pr70919.c: New test.
+
 2016-05-20  Bill Seurer  <seurer@linux.vnet.ibm.com>
 
 	* gcc.target/powerpc/vec-adde.c: Change dejagnu options, fix code
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr70919.c b/gcc/testsuite/gcc.dg/tree-ssa/pr70919.c
new file mode 100644
index 0000000..bed0ab3
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr70919.c
@@ -0,0 +1,46 @@
+/* { dg-do run } */
+/* { dg-options "-O" } */
+
+#pragma pack(1)
+struct S0
+{
+  int f0:24;
+};
+
+struct S1
+{
+  int f1;
+} a;
+
+int b, c;
+
+char
+fn1 (struct S1 p1)
+{
+  return 0;
+}
+
+int
+main ()
+{
+  c = fn1 (a);
+  if (b)
+    {
+      struct S0 f[3][9] =
+	{ { { 0 }, { 0 }, { 1 }, { 1 }, { 0 }, { 0 }, { 0 }, { 1 }, { 1 } },
+	  { { 0 }, { 0 }, { 1 }, { 1 }, { 0 }, { 0 }, { 0 }, { 1 }, { 1 } },
+	  { { 0 }, { 0 }, { 1 }, { 1 }, { 0 }, { 0 }, { 0 }, { 1 }, { 1 } }
+	};
+      b = f[1][8].f0;
+    }
+  struct S0 g[3][9] =
+	{ { { 0 }, { 0 }, { 1 }, { 1 }, { 0 }, { 0 }, { 0 }, { 1 }, { 1 } },
+	  { { 0 }, { 0 }, { 1 }, { 1 }, { 0 }, { 0 }, { 0 }, { 1 }, { 1 } },
+	  { { 0 }, { 0 }, { 1 }, { 1 }, { 0 }, { 0 }, { 0 }, { 1 }, { 1 } }
+	};
+
+  if (g[1][8].f0 != 1)
+    __builtin_abort ();
+
+  return 0;
+}
diff --git a/gcc/tree-sra.c b/gcc/tree-sra.c
index 936d3a6..7c0e90d 100644
--- a/gcc/tree-sra.c
+++ b/gcc/tree-sra.c
@@ -2074,7 +2074,8 @@ sort_and_splice_var_accesses (tree var)
       access->grp_scalar_write = grp_scalar_write;
       access->grp_assignment_read = grp_assignment_read;
       access->grp_assignment_write = grp_assignment_write;
-      access->grp_hint = multiple_scalar_reads || total_scalarization;
+      access->grp_hint = total_scalarization
+	|| (multiple_scalar_reads && !constant_decl_p (var));
       access->grp_total_scalarization = total_scalarization;
       access->grp_partial_lhs = grp_partial_lhs;
       access->grp_unscalarizable_region = unscalarizable_region;
@@ -3559,32 +3560,31 @@ initialize_constant_pool_replacements (void)
   unsigned i;
 
   EXECUTE_IF_SET_IN_BITMAP (candidate_bitmap, 0, i, bi)
-    if (bitmap_bit_p (should_scalarize_away_bitmap, i)
-	&& !bitmap_bit_p (cannot_scalarize_away_bitmap, i))
-      {
-	tree var = candidate (i);
-	if (!constant_decl_p (var))
-	  continue;
-	vec<access_p> *access_vec = get_base_access_vector (var);
-	if (!access_vec)
-	  continue;
-	for (unsigned i = 0; i < access_vec->length (); i++)
-	  {
-	    struct access *access = (*access_vec)[i];
-	    if (!access->replacement_decl)
-	      continue;
-	    gassign *stmt = gimple_build_assign (
-	      get_access_replacement (access), unshare_expr (access->expr));
-	    if (dump_file && (dump_flags & TDF_DETAILS))
-	      {
-		fprintf (dump_file, "Generating constant initializer: ");
-		print_gimple_stmt (dump_file, stmt, 0, 1);
-		fprintf (dump_file, "\n");
-	      }
-	    gsi_insert_after (&gsi, stmt, GSI_NEW_STMT);
-	    update_stmt (stmt);
-	  }
-      }
+    {
+      tree var = candidate (i);
+      if (!constant_decl_p (var))
+	continue;
+      vec<access_p> *access_vec = get_base_access_vector (var);
+      if (!access_vec)
+	continue;
+      for (unsigned i = 0; i < access_vec->length (); i++)
+	{
+	  struct access *access = (*access_vec)[i];
+	  if (!access->replacement_decl)
+	    continue;
+	  gassign *stmt
+	    = gimple_build_assign (get_access_replacement (access),
+				   unshare_expr (access->expr));
+	  if (dump_file && (dump_flags & TDF_DETAILS))
+	    {
+	      fprintf (dump_file, "Generating constant initializer: ");
+	      print_gimple_stmt (dump_file, stmt, 0, 1);
+	      fprintf (dump_file, "\n");
+	    }
+	  gsi_insert_after (&gsi, stmt, GSI_NEW_STMT);
+	  update_stmt (stmt);
+	}
+    }
 
   seq = gsi_seq (gsi);
   if (seq)