re PR middle-end/85974 (Failure to optimize difference of two pointers into a…

re PR middle-end/85974 (Failure to optimize difference of two pointers into a compile time constant)

2018-07-13  Richard Biener  <rguenther@suse.de>

	PR middle-end/85974
	* match.pd (addr1 - addr2): Allow either of the operand to
	have a conversion.

	* gcc.c-torture/compile/930326-1.c: Adjust to cover widening.

From-SVN: r262632

gcc/ChangeLog

+2018-07-13  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/85974
+	* match.pd (addr1 - addr2): Allow either of the operand to
+	have a conversion.
+
 2018-07-13  Tom de Vries  <tdevries@suse.de>
 
 	* tree-inline.c (remap_ssa_name): Save and reuse debug exprs generated

gcc/match.pd

@@ -1673,14 +1673,14 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
    (if (ptr_difference_const (@0, @1, &diff))
     { build_int_cst_type (type, diff); }))))
 (simplify
- (pointer_diff (convert?@2 ADDR_EXPR@0) (convert?@3 @1))
+ (pointer_diff (convert?@2 ADDR_EXPR@0) (convert1?@3 @1))
  (if (tree_nop_conversion_p (TREE_TYPE(@2), TREE_TYPE (@0))
       && tree_nop_conversion_p (TREE_TYPE(@3), TREE_TYPE (@1)))
   (with { poly_int64 diff; }
    (if (ptr_difference_const (@0, @1, &diff))
     { build_int_cst_type (type, diff); }))))
 (simplify
- (pointer_diff (convert?@2 @0) (convert?@3 ADDR_EXPR@1))
+ (pointer_diff (convert?@2 @0) (convert1?@3 ADDR_EXPR@1))
  (if (tree_nop_conversion_p (TREE_TYPE(@2), TREE_TYPE (@0))
       && tree_nop_conversion_p (TREE_TYPE(@3), TREE_TYPE (@1)))
   (with { poly_int64 diff; }

gcc/testsuite/ChangeLog

+2018-07-13  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/85974
+	* gcc.c-torture/compile/930326-1.c: Adjust to cover widening.
+
 2018-07-13  Tom de Vries  <tdevries@suse.de>
 
 	* gcc.dg/guality/clztest.c: Add -fno-ipa-icf in dg-options.

gcc/testsuite/gcc.c-torture/compile/930326-1.c

@@ -4,3 +4,4 @@ struct
 } s;
 
 long i = s.f-&s.b;
+long long j = s.f-&s.b;