The following revises the earlier fix which was avoiding
build_fold_addr_expr_with_type. Instead the following applies
the GENERIC simplification that this function should have done
to the pattern directly, canonicalizing (T *)(ptr - ptr_cst)
to (T *)ptr p+ cst. The pattern was originally added with
r10-7127-gcb99630f254aae.
Bootstrap and regtest running on x86_64-unknown-linux-gnu.
OK?
PR tree-optimization/127000
* match.pd ((T *)(ptr - ptr_cst)): Canonicalize directly
to (T *)ptr p+ cst.
---
gcc/match.pd | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/gcc/match.pd b/gcc/match.pd
index 1cd35ef2e2d..b886eedc567 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3561,14 +3561,13 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(if (ptr_difference_const (@0, @1, &diff))
(minus { build_int_cst_type (type, diff); } (convert @2)))))
-/* Canonicalize (T *)(ptr - ptr-cst) to &MEM[ptr + -ptr-cst]. */
+/* Canonicalize (T *)(ptr - ptr-cst) to (T *)ptr + -ptr-cst. */
(simplify
(convert (pointer_diff @0 INTEGER_CST@1))
(if (POINTER_TYPE_P (type))
- { build1 (ADDR_EXPR, type,
- build2 (MEM_REF, char_type_node, @0,
- wide_int_to_tree (ptr_type_node,
- wi::neg (wi::to_wide (@1))))); }))
+ (pointer_plus
+ (convert @0) { wide_int_to_tree (sizetype,
+ wi::neg (wi::to_wide (@1))); })))
/* If arg0 is derived from the address of an object or function, we may
be able to fold this expression using the object or function's
--
2.51.0
