* [Bug target/116564] [12/13/14/15 Regression] aarch64: gcc can't finish when compiling vst2_f64 instrinsic with opt level >= O1
2024-09-02 8:16 [Bug target/116564] New: aarch64: gcc can't finish when compiling vst2_f64 instrinsic with opt level >= O1 deminhan at gcc dot gnu.org
@ 2024-09-02 8:36 ` ktkachov at gcc dot gnu.org
2024-09-02 9:47 ` acoplan at gcc dot gnu.org
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: ktkachov at gcc dot gnu.org @ 2024-09-02 8:36 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116564
ktkachov at gcc dot gnu.org changed:
What |Removed |Added
----------------------------------------------------------------------------
Ever confirmed|0 |1
Target| |aarch64
Summary|aarch64: gcc can't finish |[12/13/14/15 Regression]
|when compiling vst2_f64 |aarch64: gcc can't finish
|instrinsic with opt level |when compiling vst2_f64
|>= O1 |instrinsic with opt level
| |>= O1
CC| |ktkachov at gcc dot gnu.org
Status|UNCONFIRMED |NEW
Last reconfirmed| |2024-09-02
Known to work| |11.4.0
Target Milestone|--- |12.5
Known to fail| |12.4.0
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug target/116564] [12/13/14/15 Regression] aarch64: gcc can't finish when compiling vst2_f64 instrinsic with opt level >= O1
2024-09-02 8:16 [Bug target/116564] New: aarch64: gcc can't finish when compiling vst2_f64 instrinsic with opt level >= O1 deminhan at gcc dot gnu.org
2024-09-02 8:36 ` [Bug target/116564] [12/13/14/15 Regression] " ktkachov at gcc dot gnu.org
@ 2024-09-02 9:47 ` acoplan at gcc dot gnu.org
2024-09-02 9:54 ` acoplan at gcc dot gnu.org
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: acoplan at gcc dot gnu.org @ 2024-09-02 9:47 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116564
Alex Coplan <acoplan at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |acoplan at gcc dot gnu.org
--- Comment #1 from Alex Coplan <acoplan at gcc dot gnu.org> ---
Looks like it's spinning running some DCE right at the start of combine:
#10 0x0000000003068ab0 in mark_insn (insn=0xfffff4fd3880, fast=true) at
/home/alecop01/toolchain/src/gcc/gcc/dce.cc:227
#11 0x000000000306b034 in dce_process_block (bb=0xfffff50220c0, redo_out=false,
au=0x4774cd8, global_debug=0xffffffffea08) at
/home/alecop01/toolchain/src/gcc/gcc/dce.cc:1035
#12 0x000000000306b41c in fast_dce (word_level=false) at
/home/alecop01/toolchain/src/gcc/gcc/dce.cc:1128
#13 0x000000000306b618 in rest_of_handle_fast_dce () at
/home/alecop01/toolchain/src/gcc/gcc/dce.cc:1197
#14 0x000000000306b6d4 in run_fast_df_dce () at
/home/alecop01/toolchain/src/gcc/gcc/dce.cc:1245
#15 0x0000000001158380 in df_lr_dce_finalize (all_blocks=0x466c6c0) at
/home/alecop01/toolchain/src/gcc/gcc/df-problems.cc:1252
#16 0x0000000001151bd8 in df_analyze_problem (dflow=0x4519c00,
blocks_to_consider=0x466c6c0, postorder=0x446f9a0, n_blocks=5) at
/home/alecop01/toolchain/src/gcc/gcc/df-core.cc:1191
#17 0x0000000001151d2c in df_analyze_1 () at
/home/alecop01/toolchain/src/gcc/gcc/df-core.cc:1236
#18 0x0000000001152180 in df_analyze () at
/home/alecop01/toolchain/src/gcc/gcc/df-core.cc:1306
#19 0x00000000030479b0 in rest_of_handle_combine () at
/home/alecop01/toolchain/src/gcc/gcc/combine.cc:15127
#20 0x0000000003047ac4 in (anonymous namespace)::pass_combine::execute
(this=0x43b35a0) at /home/alecop01/toolchain/src/gcc/gcc/combine.cc:15177
the dump file shows the following:
Finding needed instructions:
Adding insn 17 to worklist
Adding insn 10 to worklist
Adding insn 8 to worklist
Finished finding needed instructions:
processing block 4 lr out = 29 [x29] 31 [sp] 64 [sfp] 65 [ap]
processing block 3 lr out = 29 [x29] 31 [sp] 64 [sfp] 65 [ap] 101 104
Adding insn 16 to worklist
Adding insn 14 to worklist
Adding insn 13 to worklist
processing block 2 lr out = 29 [x29] 31 [sp] 64 [sfp] 65 [ap] 101
Adding insn 3 to worklist
DCE: Deleting insn 42
deleting insn with uid = 42.
DCE: Deleting insn 40
deleting insn with uid = 40.
DCE: Deleting insn 39
deleting insn with uid = 39.
DCE: Deleting insn 37
deleting insn with uid = 37.
df_worklist_dataflow_doublequeue: n_basic_blocks 5 n_edges 5 count 5 ( 1)
Finding needed instructions:
Adding insn 17 to worklist
Adding insn 10 to worklist
Adding insn 8 to worklist
Finished finding needed instructions:
processing block 4 lr out = 29 [x29] 31 [sp] 64 [sfp] 65 [ap]
processing block 3 lr out = 29 [x29] 31 [sp] 64 [sfp] 65 [ap] 101 104
Adding insn 16 to worklist
Adding insn 14 to worklist
Adding insn 13 to worklist
processing block 2 lr out = 29 [x29] 31 [sp] 64 [sfp] 65 [ap] 101
Adding insn 3 to worklist
df_worklist_dataflow_doublequeue: n_basic_blocks 5 n_edges 5 count 5 ( 1)
Finding needed instructions:
Adding insn 17 to worklist
Adding insn 10 to worklist
Adding insn 8 to worklist
Finished finding needed instructions:
processing block 4 lr out = 29 [x29] 31 [sp] 64 [sfp] 65 [ap]
processing block 3 lr out = 29 [x29] 31 [sp] 64 [sfp] 65 [ap] 101 104
Adding insn 16 to worklist
Adding insn 14 to worklist
Adding insn 13 to worklist
and it just seems to repeat adding insns {17,10,8}, then {16,14,13}, then 3.
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug target/116564] [12/13/14/15 Regression] aarch64: gcc can't finish when compiling vst2_f64 instrinsic with opt level >= O1
2024-09-02 8:16 [Bug target/116564] New: aarch64: gcc can't finish when compiling vst2_f64 instrinsic with opt level >= O1 deminhan at gcc dot gnu.org
2024-09-02 8:36 ` [Bug target/116564] [12/13/14/15 Regression] " ktkachov at gcc dot gnu.org
2024-09-02 9:47 ` acoplan at gcc dot gnu.org
@ 2024-09-02 9:54 ` acoplan at gcc dot gnu.org
2024-09-02 10:43 ` [Bug target/116564] [12/13/14/15 Regression] aarch64: gcc hangs when compiling vst2_f64 instrinsic at -O1 and above since r12-4910-g66f206b853 acoplan at gcc dot gnu.org
2024-09-02 21:46 ` pinskia at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: acoplan at gcc dot gnu.org @ 2024-09-02 9:54 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116564
--- Comment #2 from Alex Coplan <acoplan at gcc dot gnu.org> ---
Here's a preprocessed testcase (not for the testsuite, just to make it easier
to reproduce using only cc1):
#pragma GCC aarch64 "arm_neon.h"
typedef double float64_t;
__extension__ extern __inline void
__attribute__ ((__always_inline__, __gnu_inline__, __artificial__))
vst2_f64 (float64_t * __a, float64x1x2_t __val)
{
__builtin_aarch64_st2df ((__builtin_aarch64_simd_df *) __a, __val);
}
void test()
{
for (int L = 0; L < 4; ++L) {
float64_t ResData[1 * 2];
float64x1x2_t Src1;
vst2_f64(ResData, Src1);
}
}
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug target/116564] [12/13/14/15 Regression] aarch64: gcc hangs when compiling vst2_f64 instrinsic at -O1 and above since r12-4910-g66f206b853
2024-09-02 8:16 [Bug target/116564] New: aarch64: gcc can't finish when compiling vst2_f64 instrinsic with opt level >= O1 deminhan at gcc dot gnu.org
` (2 preceding siblings ...)
2024-09-02 9:54 ` acoplan at gcc dot gnu.org
@ 2024-09-02 10:43 ` acoplan at gcc dot gnu.org
2024-09-02 21:46 ` pinskia at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: acoplan at gcc dot gnu.org @ 2024-09-02 10:43 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116564
Alex Coplan <acoplan at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|[12/13/14/15 Regression] |[12/13/14/15 Regression]
|aarch64: gcc can't finish |aarch64: gcc hangs when
|when compiling vst2_f64 |compiling vst2_f64
|instrinsic with opt level |instrinsic at -O1 and above
|>= O1 |since r12-4910-g66f206b853
--- Comment #3 from Alex Coplan <acoplan at gcc dot gnu.org> ---
Started with r12-4910-g66f206b85395c273980e2b81a54dbddc4897e4a7, FWIW (could
well be a latent issue, though).
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug target/116564] [12/13/14/15 Regression] aarch64: gcc hangs when compiling vst2_f64 instrinsic at -O1 and above since r12-4910-g66f206b853
2024-09-02 8:16 [Bug target/116564] New: aarch64: gcc can't finish when compiling vst2_f64 instrinsic with opt level >= O1 deminhan at gcc dot gnu.org
` (3 preceding siblings ...)
2024-09-02 10:43 ` [Bug target/116564] [12/13/14/15 Regression] aarch64: gcc hangs when compiling vst2_f64 instrinsic at -O1 and above since r12-4910-g66f206b853 acoplan at gcc dot gnu.org
@ 2024-09-02 21:46 ` pinskia at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2024-09-02 21:46 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116564
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Alex Coplan from comment #1)
> and it just seems to repeat adding insns {17,10,8}, then {16,14,13}, then 3.
(insn 8 6 37 3 (clobber (subreg:V1DF (reg/v:V2x1DF 104 [ __valD.22804 ]) 0)) -1
(nil))
...
(insn 10 39 40 3 (clobber (subreg:V1DF (reg/v:V2x1DF 104 [ __valD.22804 ]) 8))
-1
(nil))
...
This looks exactly the same as PR 108681 but happening before register
allocation.
>could well be a latent issue, though
Well if I understand the issue is that might be a latent bug in dse but only
exposed by having the V2x1DF/V1DF and related types.
^ permalink raw reply [flat|nested] 6+ messages in thread