tinywisdom opened a new issue, #18599:
URL: https://github.com/apache/tvm/issues/18599
## Summary
Compiling a Relax IRModule converted from a PyTorch `torch.export` program
crashes with a **segmentation fault** inside TVM’s TIR pass pipeline,
specifically in:
* `tvm::tir::transform::InjectPTXLDG32(bool)`
* `tvm::tir::PTXRewriter::VisitStmt_(tvm::tir::BufferStoreNode const*)`
* `tvm::tir::BufferStore::BufferStore(...)`
This occurs while invoking `tvm.compile(...)` with:
* `target = tvm.target.Target("llvm")` (CPU-only)
* `tir_pipeline = tir.get_default_tir_pipeline(target)`
* `relax_pipeline = "default"`
* `PassContext.config` includes `"tir.ptx_ldg32": 1` plus several other flags
Even though the target is LLVM CPU, the stack trace indicates a
**PTX-specific pass / rewriter** is running and then segfaulting.
This is not a Python exception; it is a hard crash (`Segmentation fault
(core dumped)`), so it likely indicates a bug in pass gating / pipeline
selection / or an unsafe assumption in the `InjectPTXLDG32` pass when used
under this pipeline.
## Environment
From the repro output:
* TVM version: `0.22.0`
* TVM git commit: `9dbf3f22ff6f44962472f9af310fda368ca85ef2`
* LLVM: `17.0.6`
* PyTorch: `2.9.0+cu128`
* Python: `3.10.16` (inferred from stack paths)
* NumPy: `2.2.6` *(printed as “Python version” in script; see note below)*
* OS: Linux x86_64
*
## Minimal Repro Script
```python
import random
import numpy as np
import torch
import torch.nn as nn
import tvm
from tvm import tir
def print_env_info():
print("==== Environment Info ====")
print("TVM version:", getattr(tvm, "__version__", "unknown"))
print("TVM git commit:", tvm.support.libinfo()["GIT_COMMIT_HASH"])
print("TVM LLVM version:", tvm.support.libinfo().get("LLVM_VERSION",
"unknown"))
print("NumPy version:", np.__version__)
print("PyTorch version:", torch.__version__)
print("==========================\n")
def set_seed(seed: int = 0):
random.seed(seed)
np.random.seed(seed)
torch.manual_seed(seed)
class Model(nn.Module):
def __init__(self):
super().__init__()
self.net = nn.Sequential(
nn.ConvTranspose2d(100, 64, 4, 1, 0, bias=False),
nn.BatchNorm2d(64),
nn.ReLU(True),
nn.ConvTranspose2d(64, 3, 4, 2, 1, bias=False),
nn.Tanh(),
nn.Conv2d(3, 8, 3, 1, 1, bias=False),
nn.BatchNorm2d(8),
nn.LeakyReLU(0.2, inplace=True),
nn.Conv2d(8, 1, 1, 1, 0, bias=False),
nn.Sigmoid(),
)
def forward(self, x):
y = self.net(x)
return y.reshape(-1)
def export_to_relax(mod: nn.Module, x: torch.Tensor) -> tvm.IRModule:
mod = mod.to("cpu").eval()
x = x.to("cpu")
ep = torch.export.export(mod, (x,))
from tvm.relax.frontend.torch import from_exported_program
return from_exported_program(ep)
def main():
print_env_info()
set_seed(0)
target = tvm.target.Target("llvm")
tir_pipeline = tir.get_default_tir_pipeline(target)
relax_pipeline = "default"
B = 64
x = torch.rand(B, 100, 1, 1, dtype=torch.float32)
model = Model()
print("[repro] exporting torch -> relax ...")
ir_mod = export_to_relax(model, x)
pass_config = {
"relax.FuseOps.max_depth": 4,
"relax.backend.use_cuda_graph": 1,
"tir.disable_storage_rewrite": 1,
"tir.disable_vectorize": 1,
"tir.enable_debug": 1,
"tir.enable_equiv_terms_in_cse_tir": 1,
"tir.ptx_ldg32": 1,
"tir.use_async_copy": 1,
}
pc_kwargs = {
"opt_level": 1,
"disabled_pass": [
"CanonicalizeBindings",
"Simplify",
"VectorizeLoop",
"RemoveNoOp",
],
"config": pass_config,
}
print("[repro] target:", target)
print("[repro] tir_pipeline: explicit_default")
print("[repro] PassContext.config keys:", sorted(pass_config.keys()))
print("[repro] compiling with tvm.compile ...")
with tvm.transform.PassContext(**pc_kwargs):
_ = tvm.compile(
ir_mod,
target=target,
relax_pipeline=relax_pipeline,
tir_pipeline=tir_pipeline,
)
print("[repro] compile finished (no crash).")
if __name__ == "__main__":
main()
```
---
## Actual Behavior
`tvm.compile(...)` crashes with a segfault. The stack trace consistently
includes:
* `tvm::tir::BufferStore::BufferStore(...)`
* `tvm::tir::PTXRewriter::VisitStmt_(BufferStoreNode const*)`
* `tvm::tir::transform::InjectPTXLDG32(bool)`
Excerpt:
```text
!!!!!!! Segfault encountered !!!!!!!
...
tvm::tir::BufferStore::BufferStore(...)
tvm::tir::PTXRewriter::VisitStmt_(tvm::tir::BufferStoreNode const*)
...
tvm::tir::transform::PrimFuncPassNode::operator()(...)
...
tvm::tir::transform::InjectPTXLDG32(bool)
Segmentation fault (core dumped)
```
## Triage
* needs-triage
* bug
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