https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106457
--- Comment #7 from qinzhao at gcc dot gnu.org ---
another testing case failed with the current "array_at_struct_end_p":
gcc/testsuite/gcc.target/aarch64/vadd_reduc-2.c
1 /* { dg-do compile } */
2 /* { dg-additional-options "-O3 -std=c99" } */
3 /* { dg-final { check-function-bodies "**" "" "" } } */
4
5 #include <stdint.h>
6
7 #pragma GCC target "+nosve"
8
9 /*
10 **test:
11 ** ...
12 ** addv s0, v0.4s
13 ** fmov w0, s0
14 ** and w1, w0, 65535
15 ** add w0, w1, w0, lsr 16
16 ** lsr w0, w0, 1
17 ** ret
18 */
19 int test (uint8_t *p, uint32_t t[1][1], int n) {
20
21 int sum = 0;
22 uint32_t a0;
23 for (int i = 0; i < 4; i++, p++)
24 t[i][0] = p[0];
25
26 for (int i = 0; i < 4; i++) {
27 {
28 int t0 = t[0][i] + t[0][i];
29 a0 = t0;
30 };
31 sum += a0;
32 }
33 return (((uint16_t)sum) + ((uint32_t)sum >> 16)) >> 1;
34 }
in the above, at line 24, the array_ref t[i][0] was identified as "true" by the
current array_at_struct_end_p:
Breakpoint 1, array_at_struct_end_p (ref=0xfffff57a2990) at
../../latest_gcc/gcc/tree.cc:12690
12690 if (TREE_CODE (ref) == ARRAY_REF
(gdb) call debug_tree(ref)
<array_ref 0xfffff57a2990
type <integer_type 0xfffff599e310 uint32_t sizes-gimplified public unsigned
SI
size <integer_cst 0xfffff56c1050 constant 32>
unit-size <integer_cst 0xfffff56c1068 constant 4>
align:32 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0xfffff57d0690 precision:32 min <integer_cst 0xfffff56c1080 0> max <integer_cst
0xfffff56c1038 4294967295> context <translation_unit_decl 0xfffff5a00ca8 t.c>>
arg:0 <mem_ref 0xfffff59f8390
type <array_type 0xfffff5a70dc8 type <integer_type 0xfffff599e310
uint32_t>
SI size <integer_cst 0xfffff56c1050 32> unit-size <integer_cst
0xfffff56c1068 4>
align:32 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0xfffff5a70e70 domain <integer_type 0xfffff5a70d20>
pointer_to_this <pointer_type 0xfffff5a71110>>
arg:0 <ssa_name 0xfffff5761908 type <pointer_type 0xfffff5a71110>
visited
def_stmt _4 = t_27(D) + _3;
version:4
ptr-info 0xfffff56c84c0>
arg:1 <integer_cst 0xfffff56c8328 constant 0>
t.c:24:6 start: t.c:24:5 finish: t.c:24:8>
arg:1 <integer_cst 0xfffff56c11a0 type <integer_type 0xfffff57d05e8 int>
constant 0>
t.c:24:9 start: t.c:24:5 finish: t.c:24:11>
...(gdb) n
12774 if (ref
(gdb) n
12806 return true;
(gdb)
Looks like that the current array_at_struct_end_p cannot handle multi-dimension
array reference correctly.
