gimple-fold.c (get_base_constructor): Add VIEW_CONVERT case, handle all…

gimple-fold.c (get_base_constructor): Add VIEW_CONVERT case, handle all tcc_constant bases and valueize SSA names.

2016-07-19  Richard Biener  <rguenther@suse.de>

	* gimple-fold.c (get_base_constructor): Add VIEW_CONVERT case,
	handle all tcc_constant bases and valueize SSA names.
	* tree-ssa-sccvn.c (fully_constant_vn_reference_p): Handle
	tcc_constant bases.

	* c-c++-common/vector-subscript-6.c: New testcase.
	* c-c++-common/vector-subscript-7.c: Likewise.

From-SVN: r238475

gcc/ChangeLog

+2016-07-19  Richard Biener  <rguenther@suse.de>
+
+	* gimple-fold.c (get_base_constructor): Add VIEW_CONVERT case,
+	handle all tcc_constant bases and valueize SSA names.
+	* tree-ssa-sccvn.c (fully_constant_vn_reference_p): Handle
+	tcc_constant bases.
+
 2016-07-19  David Malcolm  <dmalcolm@redhat.com>
 
 	* function-tests.c (selftest::verify_three_block_rtl_cfg): Verify

gcc/gimple-fold.c

@@ -5508,6 +5508,9 @@ get_base_constructor (tree base, HOST_WIDE_INT *bit_offset,
         return NULL_TREE;
       base = TREE_OPERAND (base, 0);
     }
+  else if (valueize
+	   && TREE_CODE (base) == SSA_NAME)
+    base = valueize (base);
 
   /* Get a CONSTRUCTOR.  If BASE is a VAR_DECL, get its
      DECL_INITIAL.  If BASE is a nested reference into another
@@ -5529,6 +5532,10 @@ get_base_constructor (tree base, HOST_WIDE_INT *bit_offset,
 	return init;
       }
 
+    case VIEW_CONVERT_EXPR:
+      return get_base_constructor (TREE_OPERAND (base, 0),
+				   bit_offset, valueize);
+
     case ARRAY_REF:
     case COMPONENT_REF:
       base = get_ref_base_and_extent (base, &bit_offset2, &size, &max_size,
@@ -5538,11 +5545,13 @@ get_base_constructor (tree base, HOST_WIDE_INT *bit_offset,
       *bit_offset +=  bit_offset2;
       return get_base_constructor (base, bit_offset, valueize);
 
-    case STRING_CST:
     case CONSTRUCTOR:
       return base;
 
     default:
+      if (CONSTANT_CLASS_P (base))
+	return base;
+
       return NULL_TREE;
     }
 }

gcc/testsuite/ChangeLog

+2016-07-19  Richard Biener  <rguenther@suse.de>
+
+	* c-c++-common/vector-subscript-6.c: New testcase.
+	* c-c++-common/vector-subscript-7.c: Likewise.
+
 2016-07-19  Senthil Kumar Selvaraj  <senthil_kumar.selvaraj@atmel.com>
 
 	* gcc.dg/params/blocksort-part.c: Conditionally define Int32 

gcc/testsuite/c-c++-common/vector-subscript-6.c

+/* { dg-do compile } */
+/* { dg-options "-O -fno-tree-ccp -fdump-tree-fre1" } */
+
+typedef int v4si __attribute__ ((vector_size (16)));
+
+int
+main (int argc, char** argv)
+{
+  int i = 2;
+  int j = ((v4si){0, 1, 2, 3})[i];
+  return ((v4si){1, 2, 42, 0})[j];
+}
+
+/* { dg-final { scan-tree-dump "return 42;" "fre1" } } */

gcc/testsuite/c-c++-common/vector-subscript-7.c

+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-ccp1" } */
+
+typedef int v4si __attribute__ ((vector_size (16)));
+
+int
+main (int argc, char** argv)
+{
+  int i = 2;
+  int j = ((v4si){0, 1, 2, 3})[i];
+  return ((v4si){1, 2, 42, 0})[j];
+}
+
+/* { dg-final { scan-tree-dump "return 42;" "ccp1" } } */

gcc/tree-ssa-sccvn.c

@@ -1337,6 +1337,11 @@ fully_constant_vn_reference_p (vn_reference_t ref)
       unsigned i;
       for (i = 0; i < operands.length (); ++i)
 	{
+	  if (TREE_CODE_CLASS (operands[i].opcode) == tcc_constant)
+	    {
+	      ++i;
+	      break;
+	    }
 	  if (operands[i].off == -1)
 	    return NULL_TREE;
 	  off += operands[i].off;