https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120837
--- Comment #15 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
So, bootstrapped/regtested just the obvious removal patch:
--- gcc/c-family/c-common.cc.jj 2025-06-30 22:30:59.509417558 +0200
+++ gcc/c-family/c-common.cc 2025-06-30 22:32:01.838628609 +0200
@@ -3422,38 +3422,6 @@ pointer_int_sum (location_t loc, enum tr
they are really pointers. */
fold_defer_overflow_warnings ();
- /* If what we are about to multiply by the size of the elements
- contains a constant term, apply distributive law
- and multiply that constant term separately.
- This helps produce common subexpressions. */
- if ((TREE_CODE (intop) == PLUS_EXPR || TREE_CODE (intop) == MINUS_EXPR)
- && !TREE_CONSTANT (intop)
- && TREE_CONSTANT (TREE_OPERAND (intop, 1))
- && TREE_CONSTANT (size_exp)
- /* If the constant comes from pointer subtraction,
- skip this optimization--it would cause an error. */
- && TREE_CODE (TREE_TYPE (TREE_OPERAND (intop, 0))) == INTEGER_TYPE
- /* If the constant is unsigned, and smaller than the pointer size,
- then we must skip this optimization. This is because it could cause
- an overflow error if the constant is negative but INTOP is not. */
- && (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (intop))
- || (TYPE_PRECISION (TREE_TYPE (intop))
- == TYPE_PRECISION (TREE_TYPE (ptrop)))))
- {
- enum tree_code subcode = resultcode;
- tree int_type = TREE_TYPE (intop);
- if (TREE_CODE (intop) == MINUS_EXPR)
- subcode = (subcode == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR);
- /* Convert both subexpression types to the type of intop,
- because weird cases involving pointer arithmetic
- can result in a sum or difference with different type args. */
- ptrop = build_binary_op (EXPR_LOCATION (TREE_OPERAND (intop, 1)),
- subcode, ptrop,
- convert (int_type, TREE_OPERAND (intop, 1)),
- true);
- intop = convert (int_type, TREE_OPERAND (intop, 0));
- }
-
/* Convert the integer argument to a type the same size as sizetype
so the multiply won't overflow spuriously. */
if (TYPE_PRECISION (TREE_TYPE (intop)) != TYPE_PRECISION (sizetype)
That regressed
FAIL: c-c++-common/restrict-2.c -Wc++-compat scan-tree-dump-times lim2
"Moving statement" 11
FAIL: gcc.dg/tree-ssa/copy-headers-5.c scan-tree-dump ch2 "is now do-while
loop"
FAIL: gcc.dg/tree-ssa/copy-headers-5.c scan-tree-dump-times ch2 " if " 3
FAIL: gcc.dg/vect/pr57558-2.c scan-tree-dump vect "vectorized 1 loops"
FAIL: gcc.dg/vect/pr57558-2.c -flto -ffat-lto-objects scan-tree-dump vect
"vectorized 1 loops"
FAIL: c-c++-common/restrict-2.c -std=gnu++98 scan-tree-dump-times lim2
"Moving statement" 11
FAIL: c-c++-common/restrict-2.c -std=gnu++11 scan-tree-dump-times lim2
"Moving statement" 11
FAIL: c-c++-common/restrict-2.c -std=gnu++14 scan-tree-dump-times lim2
"Moving statement" 11
FAIL: c-c++-common/restrict-2.c -std=gnu++17 scan-tree-dump-times lim2
"Moving statement" 11
FAIL: c-c++-common/restrict-2.c -std=gnu++20 scan-tree-dump-times lim2
"Moving statement" 11
FAIL: c-c++-common/restrict-2.c -std=gnu++23 scan-tree-dump-times lim2
"Moving statement" 11
FAIL: c-c++-common/restrict-2.c -std=gnu++26 scan-tree-dump-times lim2
"Moving statement" 11
on both x86_64-linux and i686-linux.
