[Bug c/46635] c-family/c-common.c uses BITS_PER_UNIT in lieu of TYPE_PRECISION (char_type_node)

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46635

Andrew Pinski  changed:

   What|Removed |Added

   Last reconfirmed||2024-04-02
 Ever confirmed|0   |1
 Status|UNCONFIRMED |NEW

--- Comment #3 from Andrew Pinski  ---
Confirmed.

in fold_offsetof, we still have:
```
case COMPONENT_REF:
...
  off = size_binop_loc (input_location, PLUS_EXPR, DECL_FIELD_OFFSET (t),
size_int (tree_to_uhwi (DECL_FIELD_BIT_OFFSET (t))
  / BITS_PER_UNIT));

```

and:
```
case ARRAY_REF:
...
  off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t);
```

[Bug c/46635] c-family/c-common.c uses BITS_PER_UNIT in lieu of TYPE_PRECISION (char_type_node)

[egallager at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46635

--- Comment #2 from Eric Gallager  ---
(In reply to Jorn Wolfgang Rennecke from comment #1)
> As Joseph S. Myers bentioned in comment 1 of PR46633, 

(this is the last bug open blocking that one, btw)

[Bug c/46635] c-family/c-common.c uses BITS_PER_UNIT in lieu of TYPE_PRECISION (char_type_node)

[amylaar at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46635

--- Comment #1 from Jorn Wolfgang Rennecke amylaar at gcc dot gnu.org 
2010-11-24 15:49:22 UTC ---
As Joseph S. Myers bentioned in comment 1 of PR46633, if
TREE_STRING_LENGTH is considered to be measured in BITS_PER_UNIT
rather than TYPE_PRECISION (char_type_node), fix_string_type actually
has one BITS_PER_UNIT uses too few rather than three to many.

The only other place I came up with in c-common also requires even more
BITS_PER_UNIT:

@@ -8541,8 +8544,14 @@ fold_offsetof_1 (tree expr, tree stop_re
 tree
 fold_offsetof (tree expr, tree stop_ref)
 {
+  tree size = fold_offsetof_1 (expr, stop_ref);
+
+  /* Convert in case a char is more than one unit.  */
+  size
+= size_binop (CEIL_DIV_EXPR, size,
+ size_int (TYPE_PRECISION (char_type_node) / BITS_PER_UNIT));
   /* Convert back from the internal sizetype to size_t.  */
-  return convert (size_type_node, fold_offsetof_1 (expr, stop_ref));
+  return convert (size_type_node, size);
 }

 /* Warn for A ?: C expressions (with B omitted) where A is a boolean