[Feature] llama shardformer fp8 support (#5938)

* add llama shardformer fp8

* Llama Shardformer Parity

* fix typo

* fix all reduce

* fix pytest failure

* fix reduce op and move function to fp8.py

* fix typo

tests/test_fp8/test_fp8_allreduce.py

@@ -0,0 +1,48 @@
+import torch
+import torch.distributed as dist
+from torch.testing import assert_close
+
+from colossalai import launch
+from colossalai.accelerator import get_accelerator
+from colossalai.quantization.fp8 import all_reduce_fp8
+from colossalai.testing import parameterize, rerun_if_address_is_in_use, spawn
+
+
+@parameterize(
+    "shape",
+    [
+        (3, 7),
+        (4, 7),
+        (7, 4),
+        (8, 9),
+        (3),
+        (7,),
+        (8,),
+    ],
+)
+@parameterize("dtype", [torch.float16, torch.bfloat16])
+@parameterize("fp8_format", ["e4m3", "e5m2"])
+def check_4gpu(shape, dtype, fp8_format):
+    x = torch.rand(shape, dtype=dtype, device=get_accelerator().get_current_device())
+    x_fp8 = x.clone()
+    dist.all_reduce(x)
+    all_reduce_fp8(x_fp8, fp8_format=fp8_format)
+    assert_close(x, x_fp8, rtol=0.1, atol=0.1)
+
+    dist.all_reduce(x, op=dist.ReduceOp.AVG)
+    all_reduce_fp8(x_fp8, op=dist.ReduceOp.AVG, fp8_format=fp8_format)
+    assert_close(x, x_fp8, rtol=0.1, atol=0.1)
+
+
+def run_dist(rank, world_size, port):
+    launch(rank=rank, world_size=world_size, port=port, host="localhost")
+    check_4gpu()
+
+
+@rerun_if_address_is_in_use()
+def test_all_reduce():
+    spawn(run_dist, 4)
+
+
+if __name__ == "__main__":
+    test_all_reduce()