re PR tree-optimization/58417 (Incorrect optimization in SCEV const-prop)

2013-09-18  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/58417
	* tree-chrec.c (chrec_fold_plus_1): Assert that we do not
	have chrecs with symbols defined in the loop as operands.
	(chrec_fold_multiply): Likewise.
	* tree-scalar-evolution.c (interpret_rhs_expr): Instantiate
	parameters before folding binary operations.
	(struct instantiate_cache_entry_hasher): Remove.
	(struct instantiate_cache_type): Use a pointer-map.
	(instantiate_cache_type::instantiate_cache_type): New function.
	(instantiate_cache_type::get): Likewise.
	(instantiate_cache_type::set): Likewise.
	(instantiate_cache_type::~instantiate_cache_type): Adjust.
	(get_instantiated_value_entry): Likewise.
	(global_cache): New global.
	(instantiate_scev_r, instantiate_scev_poly, instantiate_scev_binary,
	instantiate_array_ref, instantiate_scev_convert, instantiate_scev_3,
	instantiate_scev_2, instantiate_scev_1): Do not pass along cache.
	(instantiate_scev_name): Adjust.
	(instantiate_scev): Construct global instead of local cache.
	(resolve_mixers): Likewise.

	* gcc.dg/torture/pr58417.c: New testcase.

From-SVN: r202700

gcc/ChangeLog

+2013-09-18  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/58417
+	* tree-chrec.c (chrec_fold_plus_1): Assert that we do not
+	have chrecs with symbols defined in the loop as operands.
+	(chrec_fold_multiply): Likewise.
+	* tree-scalar-evolution.c (interpret_rhs_expr): Instantiate
+	parameters before folding binary operations.
+	(struct instantiate_cache_entry_hasher): Remove.
+	(struct instantiate_cache_type): Use a pointer-map.
+	(instantiate_cache_type::instantiate_cache_type): New function.
+	(instantiate_cache_type::get): Likewise.
+	(instantiate_cache_type::set): Likewise.
+	(instantiate_cache_type::~instantiate_cache_type): Adjust.
+	(get_instantiated_value_entry): Likewise.
+	(global_cache): New global.
+	(instantiate_scev_r, instantiate_scev_poly, instantiate_scev_binary,
+	instantiate_array_ref, instantiate_scev_convert, instantiate_scev_3,
+	instantiate_scev_2, instantiate_scev_1): Do not pass along cache.
+	(instantiate_scev_name): Adjust.
+	(instantiate_scev): Construct global instead of local cache.
+	(resolve_mixers): Likewise.
+
 2013-09-18  Daniel Morris  <danielm@ecoscentric.com>
 	    Paolo Carlini  <paolo.carlini@oracle.com>
 

gcc/testsuite/ChangeLog

+2013-09-18  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/58417
+	* gcc.dg/torture/pr58417.c: New testcase.
+
 2013-09-18  Eric Botcazou  <ebotcazou@adacore.com>
 
 	*  gnat.dg/array_bounds_test2.adb: New test.

gcc/testsuite/gcc.dg/torture/pr58417.c

+/* { dg-do run } */
+
+long long arr[6] = {0, 1, 2, 3, 4, 5};
+extern  void abort (void);
+void __attribute__((noinline,noclone))
+foo (long long sum)
+{
+  asm ("");
+}
+int main()
+{
+  int i, n = 5;
+  long long sum = 0, prevsum = 0;
+
+  for(i = 1; i <= n; i++)
+    {
+      foo (sum);
+      sum = (i - 1) * arr[i] - prevsum;
+      prevsum += arr[i];
+    }
+
+  if (sum != 10)
+    abort ();
+  return 0;
+}

gcc/tree-chrec.c

@@ -268,9 +268,14 @@ chrec_fold_plus_1 (enum tree_code code, tree type,
   switch (TREE_CODE (op0))
     {
     case POLYNOMIAL_CHREC:
+      gcc_checking_assert
+	(!chrec_contains_symbols_defined_in_loop (op0, CHREC_VARIABLE (op0)));
       switch (TREE_CODE (op1))
 	{
 	case POLYNOMIAL_CHREC:
+	  gcc_checking_assert
+	    (!chrec_contains_symbols_defined_in_loop (op1,
+						      CHREC_VARIABLE (op1)));
 	  return chrec_fold_plus_poly_poly (code, type, op0, op1);
 
 	CASE_CONVERT:
@@ -298,6 +303,9 @@ chrec_fold_plus_1 (enum tree_code code, tree type,
       switch (TREE_CODE (op1))
 	{
 	case POLYNOMIAL_CHREC:
+	  gcc_checking_assert
+	    (!chrec_contains_symbols_defined_in_loop (op1,
+						      CHREC_VARIABLE (op1)));
 	  if (code == PLUS_EXPR || code == POINTER_PLUS_EXPR)
 	    return build_polynomial_chrec
 	      (CHREC_VARIABLE (op1),
@@ -396,9 +404,14 @@ chrec_fold_multiply (tree type,
   switch (TREE_CODE (op0))
     {
     case POLYNOMIAL_CHREC:
+      gcc_checking_assert
+	(!chrec_contains_symbols_defined_in_loop (op0, CHREC_VARIABLE (op0)));
       switch (TREE_CODE (op1))
 	{
 	case POLYNOMIAL_CHREC:
+	  gcc_checking_assert
+	    (!chrec_contains_symbols_defined_in_loop (op1,
+						      CHREC_VARIABLE (op1)));
 	  return chrec_fold_multiply_poly_poly (type, op0, op1);
 
 	CASE_CONVERT:
@@ -431,6 +444,9 @@ chrec_fold_multiply (tree type,
       switch (TREE_CODE (op1))
 	{
 	case POLYNOMIAL_CHREC:
+	  gcc_checking_assert
+	    (!chrec_contains_symbols_defined_in_loop (op1,
+						      CHREC_VARIABLE (op1)));
 	  return build_polynomial_chrec
 	    (CHREC_VARIABLE (op1),
 	     chrec_fold_multiply (type, CHREC_LEFT (op1), op0),