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| author | Richard Biener <rguenther@suse.de> | 2025-01-30 11:22:37 +0100 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2025-01-30 13:05:37 +0100 |
| commit | 9ba2de71815c0ea6cc940ecb50af7cc1a84579f7 (patch) | |
| tree | 8d96196c314af8f5b75c71c225b64eeee1615855 /gcc/expr.cc | |
| parent | 34d8c842b8d12c69b9335f1b63453920f056e6e1 (diff) | |
| download | gcc-9ba2de71815c0ea6cc940ecb50af7cc1a84579f7.zip gcc-9ba2de71815c0ea6cc940ecb50af7cc1a84579f7.tar.gz gcc-9ba2de71815c0ea6cc940ecb50af7cc1a84579f7.tar.bz2 | |
middle-end/118695 - missed misalign handling in MEM_REF expansion
When MEM_REF expansion of a non-MEM falls back to a stack temporary
we fail to handle the case where the offset adjusted reference to
the temporary is not aligned according to the requirement of the
mode. We have to go through bitfield extraction or movmisalign
in this case. Fortunately there's a helper for this.
This fixes an ICE observed on arm which has sanity checks in its
move patterns for this.
PR middle-end/118695
* expr.cc (expand_expr_real_1): When expanding a MEM_REF
to a non-MEM by committing it to a stack temporary make
sure to handle misaligned accesses correctly.
* gcc.dg/pr118695.c: New testcase.
Diffstat (limited to 'gcc/expr.cc')
| -rw-r--r-- | gcc/expr.cc | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/gcc/expr.cc b/gcc/expr.cc index 10467f8..f684e26 100644 --- a/gcc/expr.cc +++ b/gcc/expr.cc @@ -11796,6 +11796,7 @@ expand_expr_real_1 (tree exp, rtx target, machine_mode tmode, && known_eq (GET_MODE_BITSIZE (DECL_MODE (base)), type_size)) return expand_expr (build1 (VIEW_CONVERT_EXPR, type, base), target, tmode, modifier); + unsigned align; if (TYPE_MODE (type) == BLKmode || maybe_lt (offset, 0)) { temp = assign_stack_temp (DECL_MODE (base), @@ -11804,6 +11805,17 @@ expand_expr_real_1 (tree exp, rtx target, machine_mode tmode, temp = adjust_address (temp, TYPE_MODE (type), offset); if (TYPE_MODE (type) == BLKmode) set_mem_size (temp, int_size_in_bytes (type)); + /* When the original ref was misaligned so will be the + access to the stack temporary. Not all targets handle + this correctly, some will ICE in sanity checking. + Handle this by doing bitfield extraction when necessary. */ + else if ((align = get_object_alignment (exp)) + < GET_MODE_ALIGNMENT (TYPE_MODE (type))) + temp + = expand_misaligned_mem_ref (temp, TYPE_MODE (type), + unsignedp, align, + modifier == EXPAND_STACK_PARM + ? NULL_RTX : target, NULL); return temp; } /* When the access is fully outside of the underlying object |