From caa1c2f42691d68af4d894a5c3e700ecd2dba080 Mon Sep 17 00:00:00 2001 From: Andrew Pinski Date: Tue, 2 Sep 2025 13:57:26 -0700 Subject: [PATCH] strlen: Fixup load alignment for memcmp Like the previous commit but for strlen copy so we can backport this commit. The loads should have the correct alignment on them so we need to create newly aligned types when the alignment of the pointer is less than the alignment of the current type. Pushed as pre-approved by https://gcc.gnu.org/pipermail/gcc-patches/2025-September/694016.html after a bootstrap/test on x86_64-linux-gnu. gcc/ChangeLog: * tree-ssa-strlen.cc (strlen_pass::handle_builtin_memcmp): Create unaligned types if the alignment of the pointers is less than the alignment of the new type. Signed-off-by: Andrew Pinski --- gcc/tree-ssa-strlen.cc | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/gcc/tree-ssa-strlen.cc b/gcc/tree-ssa-strlen.cc index c4d64132e53..3cef33bf5b0 100644 --- a/gcc/tree-ssa-strlen.cc +++ b/gcc/tree-ssa-strlen.cc @@ -4009,8 +4009,16 @@ strlen_pass::handle_builtin_memcmp () tree ptrtype = build_pointer_type_for_mode (char_type_node, ptr_mode, true); off = build_int_cst (ptrtype, 0); - arg1 = build2_loc (loc, MEM_REF, type, arg1, off); - arg2 = build2_loc (loc, MEM_REF, type, arg2, off); + + /* Create unaligned types if needed. */ + tree type1 = type, type2 = type; + if (TYPE_ALIGN (type1) > align1) + type1 = build_aligned_type (type1, align1); + if (TYPE_ALIGN (type2) > align2) + type2 = build_aligned_type (type2, align2); + + arg1 = build2_loc (loc, MEM_REF, type1, arg1, off); + arg2 = build2_loc (loc, MEM_REF, type2, arg2, off); tree tem1 = fold_const_aggregate_ref (arg1); if (tem1) arg1 = tem1; -- 2.43.0