https://gcc.gnu.org/g:86661d826d736df190264ecb39af143b16e78f2d
commit 86661d826d736df190264ecb39af143b16e78f2d
Author: Mikael Morin <mik...@gcc.gnu.org>
Date: Tue Apr 29 11:29:26 2025 +0200
Sauvegarde simplification MEM_REF.
Diff:
---
gcc/gimple-fold.cc | 52 ++++++++++++++++++++++++++++++++++++++++------------
1 file changed, 40 insertions(+), 12 deletions(-)
diff --git a/gcc/gimple-fold.cc b/gcc/gimple-fold.cc
index 729080ad6e5b..708083e6db0e 100644
--- a/gcc/gimple-fold.cc
+++ b/gcc/gimple-fold.cc
@@ -327,6 +327,12 @@ maybe_fold_reference (tree expr)
if (result && is_gimple_min_invariant (result))
return result;
+ if (result
+ && TREE_CODE (result) == MEM_REF
+ && TREE_CODE (expr) == ARRAY_REF
+ && TREE_CODE (TREE_OPERAND (expr, 0)) == MEM_REF)
+ return result;
+
return NULL_TREE;
}
@@ -10068,9 +10074,10 @@ fold_const_aggregate_ref_1 (tree t, tree (*valueize)
(tree))
FIXME: This code can't handle nested references with variable indexes
(they will be handled only by iteration of ccp). Perhaps we can bring
get_ref_base_and_extent here and make it use a valueize callback. */
- if (TREE_CODE (TREE_OPERAND (t, 1)) == SSA_NAME
- && valueize
- && (idx = (*valueize) (TREE_OPERAND (t, 1)))
+ if (((TREE_CODE (TREE_OPERAND (t, 1)) == SSA_NAME
+ && valueize
+ && (idx = (*valueize) (TREE_OPERAND (t, 1))))
+ || (idx = TREE_OPERAND (t, 1)))
&& poly_int_tree_p (idx))
{
tree low_bound, unit_size;
@@ -10081,12 +10088,13 @@ fold_const_aggregate_ref_1 (tree t, tree (*valueize)
(tree))
&& (unit_size = array_ref_element_size (t),
tree_fits_uhwi_p (unit_size)))
{
- poly_offset_int woffset
+ poly_offset_int woffset, woffset_bytes;
+ woffset_bytes
= wi::sext (wi::to_poly_offset (idx)
- wi::to_poly_offset (low_bound),
TYPE_PRECISION (sizetype));
- woffset *= tree_to_uhwi (unit_size);
- woffset *= BITS_PER_UNIT;
+ woffset_bytes *= tree_to_uhwi (unit_size);
+ woffset = woffset_bytes * BITS_PER_UNIT;
if (woffset.to_shwi (&offset))
{
base = TREE_OPERAND (t, 0);
@@ -10099,12 +10107,32 @@ fold_const_aggregate_ref_1 (tree t, tree (*valueize)
(tree))
if (maybe_lt (offset, 0))
return NULL_TREE;
/* We cannot determine ctor. */
- if (!ctor)
- return NULL_TREE;
- return fold_ctor_reference (TREE_TYPE (t), ctor, offset,
- tree_to_uhwi (unit_size)
- * BITS_PER_UNIT,
- base);
+ if (ctor)
+ return fold_ctor_reference (TREE_TYPE (t), ctor, offset,
+ tree_to_uhwi (unit_size)
+ * BITS_PER_UNIT,
+ base);
+ if (TREE_CODE (base) == MEM_REF)
+ {
+ woffset_bytes += wi::to_offset (TREE_OPERAND (base, 1));
+ tree offset_type = TREE_TYPE (TREE_OPERAND (base, 1));
+ if (TREE_CODE (offset_type) == POINTER_TYPE
+ && TREE_CODE (TREE_TYPE (offset_type)) == ARRAY_TYPE)
+ {
+ tree type = build_pointer_type (
+ TREE_TYPE (TREE_TYPE (offset_type)));
+ if (wi::fits_to_tree_p (woffset_bytes, type))
+ {
+ tree offset = wide_int_to_tree (type,
+ woffset_bytes);
+ return fold_build2_loc (EXPR_LOCATION (t),
MEM_REF,
+ TREE_TYPE (t),
+ TREE_OPERAND (base, 0),
+ offset);
+ }
+ }
+
+ }
}
}
}
