transformers生成CausalAttentionMask的上三角-inf矩阵：
python
import torch
import torch_xla
import torch_xla.core.xla_model as xm
import os
os.environ['PJRT_DEVICE']='IPU'
# os.environ['PJRT_DEVICE']='GPU'
# os.environ['XLA_FLAGS']='--xla_dump_to=gen_AttnFwd-XLA_GPU'
tgt_len = 10
dtype=torch.float32
device = xm.xla_device()
# src/transformers/modeling_attn_mask_utils.py#AttentionMaskConverter::_make_causal_mask
mask = torch.full((tgt_len, tgt_len), torch.finfo(dtype).min, device=device)
mask_cond = torch.arange(mask.size(-1), device=device)
mask.masked_fill_(mask_cond < (mask_cond + 1).view(mask.size(-1), 1), 0)
mask = mask.to(dtype)
print(mask)
# print(mask.size())
# print(mask[3][3])
"""
2024-11-07 07:16:18.824506: F tensorflow/compiler/xla/service/hlo_computation.cc:70] Check failed: nullptr != root (nullptr vs. 0)
Aborted (core dumped)
"""
'''
module @SyncTensorsGraph.25 {
func.func @main() -> tuple<tensor<10x10xf32>> {
%0 = mhlo.constant dense<[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]> : tensor<10xi64>
%1 = "mhlo.broadcast_in_dim"(%0) {broadcast_dimensions = dense<1> : tensor<1xi64>} : (tensor<10xi64>) -> tensor<10x10xi64>
%2 = mhlo.constant dense<[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]> : tensor<10xi64>
%3 = "mhlo.broadcast_in_dim"(%2) {broadcast_dimensions = dense<0> : tensor<1xi64>} : (tensor<10xi64>) -> tensor<10x10xi64>
%4 = mhlo.compare LT, %1, %3 : (tensor<10x10xi64>, tensor<10x10xi64>) -> tensor<10x10xi1>
%5 = mhlo.constant dense<false> : tensor<i1>
%6 = "mhlo.broadcast_in_dim"(%5) {broadcast_dimensions = dense<> : tensor<0xi64>} : (tensor<i1>) -> tensor<10x10xi1>
%7 = mhlo.compare NE, %4, %6 : (tensor<10x10xi1>, tensor<10x10xi1>) -> tensor<10x10xi1>
%8 = mhlo.constant dense<0.000000e+00> : tensor<f32>
%9 = "mhlo.broadcast_in_dim"(%8) {broadcast_dimensions = dense<> : tensor<0xi64>} : (tensor<f32>) -> tensor<10x10xf32>
%10 = mhlo.constant dense<-3.40282347E+38> : tensor<f32>
%11 = "mhlo.broadcast_in_dim"(%10) {broadcast_dimensions = dense<> : tensor<0xi64>} : (tensor<f32>) -> tensor<10x10xf32>
%12 = "mhlo.select"(%7, %9, %11) : (tensor<10x10xi1>, tensor<10x10xf32>, tensor<10x10xf32>) -> tensor<10x10xf32>
%13 = "mhlo.tuple"(%12) {xla_shape = "(f32[10,10]{1,0})"} : (tensor<10x10xf32>) -> tuple<tensor<10x10xf32>>
return %13 : tuple<tensor<10x10xf32>>
}
}
'''
'''
XLA_GPU甚至给出了完整的mhlo实现：
gen_AttnFwd-XLA_GPU/module_0000.SyncTensorsGraph.25.sm_8.0_gpu_after_optimizations.txt
HloModule SyncTensorsGraph.25, entry_computation_layout={(f32[])->(f32[10,10]{1,0})}
fused_computation {
iota.3 = s64[10,10]{1,0} iota(), iota_dimension=1
iota.2 = s64[10]{0} iota(), iota_dimension=0
constant_5 = s64[] constant(1)
broadcast.7 = s64[10]{0} broadcast(constant_5), dimensions={}
add.0 = s64[10]{0} add(iota.2, broadcast.7)
broadcast.6 = s64[10,10]{1,0} broadcast(add.0), dimensions={0}
compare.1 = pred[10,10]{1,0} compare(iota.3, broadcast.6), direction=LT
constant_3 = pred[] constant(false)
broadcast.4 = pred[10,10]{1,0} broadcast(constant_3), dimensions={}
compare.0 = pred[10,10]{1,0} compare(compare.1, broadcast.4), direction=NE
constant_0 = f32[] constant(0)
broadcast.3 = f32[10,10]{1,0} broadcast(constant_0), dimensions={}
param_0.1 = f32[] parameter(0)
broadcast.2 = f32[10,10]{1,0} broadcast(param_0.1), dimensions={}
ROOT select.0 = f32[10,10]{1,0} select(compare.0, broadcast.3, broadcast.2)
}
ENTRY SyncTensorsGraph.25 {
p0.13 = f32[] parameter(0)
fusion = f32[10,10]{1,0} fusion(p0.13), kind=kLoop, calls=fused_computation
ROOT tuple.24 = (f32[10,10]{1,0}) tuple(fusion)
}
-----
INFO:torch_xla:Letting libtpu.so load fail during _XLAC import. libtpu.so will be loaded from `libtpu` Python package when the ComputationClient is created.
2024-11-07 11:50:41.174644: I tensorflow/compiler/xla/service/service.cc:173] XLA service 0x905c190 initialized for platform CUDA (this does not guarantee that XLA will be used). Devices:
2024-11-07 11:50:41.174714: I tensorflow/compiler/xla/service/service.cc:181] StreamExecutor device (0): NVIDIA A100-SXM4-80GB, Compute Capability 8.0
2024-11-07 11:50:41.175641: I tensorflow/compiler/xla/pjrt/gpu/se_gpu_pjrt_client.cc:194] Using BFC allocator.
2024-11-07 11:50:41.175713: I tensorflow/compiler/xla/pjrt/gpu/gpu_helpers.cc:105] XLA backend allocating 75175958937 bytes on device 0 for BFCAllocator.
2024-11-07 11:50:42.013482: I tensorflow/compiler/xla/service/dump.cc:485] HloModule dump enabled with path prefix: , suffix: before_optimizations
2024-11-07 11:50:42.037845: I tensorflow/tsl/platform/default/subprocess.cc:304] Start cannot spawn child process: No such file or directory
tensor([[ 0.0000e+00, -3.4028e+38, -3.4028e+38, -3.4028e+38, -3.4028e+38,
-3.4028e+38, -3.4028e+38, -3.4028e+38, -3.4028e+38, -3.4028e+38],
[ 0.0000e+00, 0.0000e+00, -3.4028e+38, -3.4028e+38, -3.4028e+38,
-3.4028e+38, -3.4028e+38, -3.4028e+38, -3.4028e+38, -3.4028e+38],
[ 0.0000e+00, 0.0000e+00, 0.0000e+00, -3.4028e+38, -3.4028e+38,
-3.4028e+38, -3.4028e+38, -3.4028e+38, -3.4028e+38, -3.4028e+38],
[ 0.0000e+00, 0.0000e+00, 0.0000e+00, 0.0000e+00, -3.4028e+38,
-3.4028e+38, -3.4028e+38, -3.4028e+38, -3.4028e+38, -3.4028e+38],
[ 0.0000e+00, 0.0000e+00, 0.0000e+00, 0.0000e+00, 0.0000e+00,
-3.4028e+38, -3.4028e+38, -3.4028e+38, -3.4028e+38, -3.4028e+38],
[ 0.0000e+00, 0.0000e+00, 0.0000e+00, 0.0000e+00, 0.0000e+00,
0.0000e+00, -3.4028e+38, -3.4028e+38, -3.4028e+38, -3.4028e+38],
[ 0.0000e+00, 0.0000e+00, 0.0000e+00, 0.0000e+00, 0.0000e+00,
0.0000e+00, 0.0000e+00, -3.4028e+38, -3.4028e+38, -3.4028e+38],
[ 0.0000e+00, 0.0000e+00, 0.0000e+00, 0.0000e+00, 0.0000e+00,
0.0000e+00, 0.0000e+00, 0.0000e+00, -3.4028e+38, -3.4028e+38],
[ 0.0000e+00, 0.0000e+00, 0.0000e+00, 0.0000e+00, 0.0000e+00,
0.0000e+00, 0.0000e+00, 0.0000e+00, 0.0000e+00, -3.4028e+38],
[ 0.0000e+00, 0.0000e+00, 0.0000e+00, 0.0000e+00, 0.0000e+00,
0.0000e+00, 0.0000e+00, 0.0000e+00, 0.0000e+00, 0.0000e+00]],
device='xla:0')
'''