https://gcc.gnu.org/g:caa1c2f42691d68af4d894a5c3e700ecd2dba080
commit r16-3531-gcaa1c2f42691d68af4d894a5c3e700ecd2dba080
Author: Andrew Pinski <andrew.pin...@oss.qualcomm.com>
Date: Tue Sep 2 13:57:26 2025 -0700
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 <andrew.pin...@oss.qualcomm.com>
Diff:
---
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 c4d64132e538..3cef33bf5b07 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;
