[gcc r12-6056] tree-optimization/103759: Use sizetype everywhere for object sizes

[gcc r12-6056] tree-optimization/103759: Use sizetype everywhere for object sizes

[Siddhesh Poyarekar]

https://gcc.gnu.org/g:cc032ec1ecb34b006f42e170ccb9d76aa42fd8eb

commit r12-6056-gcc032ec1ecb34b006f42e170ccb9d76aa42fd8eb
Author: Siddhesh Poyarekar <siddhesh@gotplt.org>
Date:   Sat Dec 18 16:46:43 2021 +0530

    tree-optimization/103759: Use sizetype everywhere for object sizes
    
    Since all computations in tree-object-size are now done in sizetype and
    not HOST_WIDE_INT, comparisons with HOST_WIDE_INT based unknown and
    initval would be incorrect.  Instead, use the sizetype trees directly to
    generate and evaluate initval and unknown size values.
    
    gcc/ChangeLog:
    
            PR tree-optimization/103759
            * tree-object-size.c (unknown, initval): Remove functions.
            (size_unknown, size_initval, size_unknown_p): Operate directly
            on trees.
    
    Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org>

Diff:
---
 gcc/tree-object-size.c | 27 ++++++---------------------
 1 file changed, 6 insertions(+), 21 deletions(-)

diff --git a/gcc/tree-object-size.c b/gcc/tree-object-size.c
index 71f6b747d05..ee9ea1bfbfd 100644
--- a/gcc/tree-object-size.c
+++ b/gcc/tree-object-size.c
@@ -83,30 +83,13 @@ static bitmap computed[OST_END];
 /* Maximum value of offset we consider to be addition.  */
 static unsigned HOST_WIDE_INT offset_limit;
 
-/* Initial value of object sizes; zero for maximum and SIZE_MAX for minimum
-   object size.  */
-
-static inline unsigned HOST_WIDE_INT
-initval (int object_size_type)
-{
-  return (object_size_type & OST_MINIMUM) ? HOST_WIDE_INT_M1U : 0;
-}
-
-/* Unknown object size value; it's the opposite of initval.  */
-
-static inline unsigned HOST_WIDE_INT
-unknown (int object_size_type)
-{
-  return ~initval (object_size_type);
-}
-
 /* Return true if VAL is represents an unknown size for OBJECT_SIZE_TYPE.  */
 
 static inline bool
 size_unknown_p (tree val, int object_size_type)
 {
-  return (tree_fits_uhwi_p (val)
-	  && tree_to_uhwi (val) == unknown (object_size_type));
+  return ((object_size_type & OST_MINIMUM)
+	  ? integer_zerop (val) : integer_all_onesp (val));
 }
 
 /* Return a tree with initial value for OBJECT_SIZE_TYPE.  */
@@ -114,7 +97,8 @@ size_unknown_p (tree val, int object_size_type)
 static inline tree
 size_initval (int object_size_type)
 {
-  return size_int (initval (object_size_type));
+  return ((object_size_type & OST_MINIMUM)
+	  ? TYPE_MAX_VALUE (sizetype) : size_zero_node);
 }
 
 /* Return a tree with unknown value for OBJECT_SIZE_TYPE.  */
@@ -122,7 +106,8 @@ size_initval (int object_size_type)
 static inline tree
 size_unknown (int object_size_type)
 {
-  return size_int (unknown (object_size_type));
+  return ((object_size_type & OST_MINIMUM)
+	  ? size_zero_node : TYPE_MAX_VALUE (sizetype));
 }
 
 /* Grow object_sizes[OBJECT_SIZE_TYPE] to num_ssa_names.  */