pytorch / pytorch/pytorch

[inductor] generated kernel calls `empty_strided_cpu` with a negative stride → `Expected result >= 0`

Open
#188,227 1 comment 0 reactions 0 assignees View on GitHub
bot-triaged oncall: cpu inductor oncall: pt2
Dominant language
Python
Stars
103k
Forks
29.5k
PR merge metrics
PR metrics pending

Description

### 🐛 Describe the bug

The Inductor-generated kernel emits `empty_strided_cpu((0, 0), (-1, 0), ...)` with a negative stride, which fails at runtime. Eager mode produces a valid tensor; only the `torch.compile(backend="inductor")` path fails. Ops involved: `float_power`, `empty_strided`, `gather`.

## Repro
```python
# Minimal repro for crash 31947ae5 (compiled-only: eager OK, inductor crashes)
import torch, torch.nn as nn, torch.nn.functional as F

torch.manual_seed(0)
t31856 = torch.randn([3, 3], dtype=torch.complex64)

def model_259():
t31857 = torch.float_power(t31856, 0.024490423949617878)
t31851 = torch.empty_strided((0, 0), (-1, 0), dtype=torch.bool, pin_memory=False, requires_grad=False)
t31858 = torch.gather(t31857, -2, t31851)
return t31858

# eager baseline -- succeeds
eager_out = model_259()
print("eager OK:", type(eager_out))

# inductor compile -- crashes
compiled = torch.compile(model_259, backend="inductor")
with torch.no_grad():
compiled_out = compiled()
print("compiled OK:", type(compiled_out))
```
Eager runs successfully (`eager OK` prints); the crash happens in the compiled call.

### Error logs

```
Traceback (most recent call last):
File "/home/crash_analysis/torch/programs//_bug_drafts/repro_31947ae5.py", line 20, in
compiled_out = compiled()
File "/home/.venv/lib/python3.10/site-packages/torch/_dynamo/eval_frame.py", line 1024, in compile_wrapper
return fn(*args, **kwargs)
File "/home/crash_analysis/torch/programs//_bug_drafts/repro_31947ae5.py", line 7, in model_259
def model_259():
File "/home/.venv/lib/python3.10/site-packages/torch/_dynamo/eval_frame.py", line 1263, in _fn
return fn(*args, **kwargs)
File "/home/.venv/lib/python3.10/site-packages/torch/_functorch/aot_autograd.py", line 1200, in forward
return compiled_fn(full_args)
File "/home/.venv/lib/python3.10/site-packages/torch/_functorch/_aot_autograd/runtime_wrappers.py", line 580, in runtime_wrapper
all_outs = call_func_at_runtime_with_args(
File "/home/.venv/lib/python3.10/site-packages/torch/_functorch/_aot_autograd/utils.py", line 138, in call_func_at_runtime_with_args
out = normalize_as_list(f(args))
File "/home/.venv/lib/python3.10/site-packages/torch/_functorch/_aot_autograd/runtime_wrappers.py", line 2298, in __call__
return self.compiled_fn(*args, **kwargs)
File "/home/.venv/lib/python3.10/site-packages/torch/_functorch/_aot_autograd/runtime_wrappers.py", line 783, in wrapper
return compiled_fn(runtime_args)
File "/home/.venv/lib/python3.10/site-packages/torch/_functorch/_aot_autograd/runtime_wrappers.py", line 1011, in inner_fn
outs = compiled_fn(args)
File "/home/.venv/lib/python3.10/site-packages/torch/_inductor/output_code.py", line 656, in __call__
return self.current_callable(inputs)
File "/tmp/torchinductor_lliu39/jh/cjhztpj5odswxjbccwnqoden5szrrtetszy5t3dzhw5nejt5kgrq.py", line 64, in call
buf4 = empty_strided_cpu((0, 0), (-1, 0), torch.bool)
RuntimeError: Expected result >= 0 to be true, but got false. (Could this error message be improved? If so, please report an enhancement request to PyTorch.)
```

### Versions

Collecting environment information...
PyTorch version: 2.11.0+cu130
Is debug build: False
CUDA used to build PyTorch: 13.0
ROCM used to build PyTorch: N/A

OS: Ubuntu 22.04.5 LTS (x86_64)
GCC version: (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0
Clang version: 15.0.0 ([git@github.com](mailto:git@github.com):llvm/llvm-project.git 4ba6a9c9f65bbc8bd06e3652cb20fd4dfc846137)
CMake version: version 3.22.1
Libc version: glibc-2.35

Python version: 3.10.12 (main, Mar 3 2026, 11:56:32) [GCC 11.4.0] (64-bit runtime)
Python platform: Linux-6.8.0-94-generic-x86_64-with-glibc2.35
Is CUDA available: False
CUDA runtime version: No CUDA
CUDA_MODULE_LOADING set to: N/A
GPU models and configuration: No CUDA
Nvidia driver version: No CUDA
cuDNN version: No CUDA
Is XPU available: False
HIP runtime version: N/A
MIOpen runtime version: N/A
Is XNNPACK available: True
Caching allocator config: N/A

CPU:
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Address sizes: 52 bits physical, 57 bits virtual
Byte Order: Little Endian
CPU(s): 384
On-line CPU(s) list: 0-383
Vendor ID: AuthenticAMD
Model name: AMD EPYC 9684X 96-Core Processor
CPU family: 25
Model: 17
Thread(s) per core: 2
Core(s) per socket: 96
Socket(s): 2
Stepping: 2
BogoMIPS: 5099.98
Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good amd_lbr_v2 nopl nonstop_tsc cpuid extd_apicid aperfmperf rapl pni pclmulqdq monitor ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt aes xsave avx f16c rdrand lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt tce topoext perfctr_core perfctr_nb bpext perfctr_llc mwaitx cpb cat_l3 cdp_l3 hw_pstate ssbd mba perfmon_v2 ibrs ibpb stibp ibrs_enhanced vmmcall fsgsbase bmi1 avx2 smep bmi2 erms invpcid cqm rdt_a avx512f avx512dq rdseed adx smap avx512ifma clflushopt clwb avx512cd sha_ni avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves cqm_llc cqm_occup_llc cqm_mbm_total cqm_mbm_local user_shstk avx512_bf16 clzero irperf xsaveerptr rdpru wbnoinvd amd_ppin cppc amd_ibpb_ret arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold avic v_vmsave_vmload vgif x2avic v_spec_ctrl vnmi avx512vbmi umip pku ospke avx512_vbmi2 gfni vaes vpclmulqdq avx512_vnni avx512_bitalg avx512_vpopcntdq la57 rdpid overflow_recov succor smca fsrm flush_l1d debug_swap ibpb_exit_to_user
Virtualization: AMD-V
L1d cache: 6 MiB (192 instances)
L1i cache: 6 MiB (192 instances)
L2 cache: 192 MiB (192 instances)
L3 cache: 2.3 GiB (24 instances)
NUMA node(s): 2
NUMA node0 CPU(s): 0-95,192-287
NUMA node1 CPU(s): 96-191,288-383
Vulnerability Gather data sampling: Not affected
Vulnerability Itlb multihit: Not affected
Vulnerability L1tf: Not affected
Vulnerability Mds: Not affected
Vulnerability Meltdown: Not affected
Vulnerability Mmio stale data: Not affected
Vulnerability Reg file data sampling: Not affected
Vulnerability Retbleed: Not affected
Vulnerability Spec rstack overflow: Mitigation; Safe RET
Vulnerability Spec store bypass: Mitigation; Speculative Store Bypass disabled via prctl
Vulnerability Spectre v1: Mitigation; usercopy/swapgs barriers and __user pointer sanitization
Vulnerability Spectre v2: Mitigation; Enhanced / Automatic IBRS; IBPB conditional; STIBP always-on; RSB filling; PBRSB-eIBRS Not affected; BHI Not affected
Vulnerability Srbds: Not affected
Vulnerability Tsx async abort: Not affected
Vulnerability Vmscape: Mitigation; IBPB before exit to userspace

Versions of relevant libraries:
[pip3] numpy==2.2.6
[pip3] nvidia-cublas==13.1.0.3
[pip3] nvidia-cuda-cupti==13.0.85
[pip3] nvidia-cuda-nvrtc==13.0.88
[pip3] nvidia-cuda-runtime==13.0.96
[pip3] nvidia-cudnn-cu13==9.19.0.56
[pip3] nvidia-cufft==12.0.0.61
[pip3] nvidia-curand==10.4.0.35
[pip3] nvidia-cusolver==12.0.4.66
[pip3] nvidia-cusparse==12.6.3.3
[pip3] nvidia-cusparselt-cu13==0.8.0
[pip3] nvidia-nccl-cu13==2.28.9
[pip3] nvidia-nvjitlink==13.0.88
[pip3] nvidia-nvtx==13.0.85
[pip3] optree==0.19.0
[pip3] torch==2.11.0
[pip3] triton==3.6.0
[conda] Could not collect

cc @chauhang @penguinwu

Contributor guide

Open the contributing guide

Research direction

Run the minimal Python repro with torch.compile(..., backend="inductor") and inspect the generated output_code.py at the call that emits empty_strided_cpu((0, 0), (-1, 0), ...). Trace how the float_power, empty_strided, and gather operations produce that allocation. Done means the compiled call no longer fails and its result matches eager mode.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
compilers
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Quiet
Clarity
Clearly specified
Newbie friendliness
48/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.