From 0781eb1f2edeb315002e3b2f05a3d28e3cdb74c3 Mon Sep 17 00:00:00 2001
From: Phil Wang <lucidrains@gmail.com>
Date: Tue, 9 May 2023 18:52:14 -0700
Subject: [PATCH] Revert "actually, just follow @ipoletaev advice and remove
 autotuner for now"

This reverts commit 2226ec8aeee03e9fbbf561e50fbf114b9677d3e9.
---
 lion_pytorch/lion_pytorch.py | 17 +++++++++-----
 lion_pytorch/triton.py       | 43 +++++++++++++++++++-----------------
 setup.py                     |  2 +-
 3 files changed, 36 insertions(+), 26 deletions(-)

diff --git a/lion_pytorch/lion_pytorch.py b/lion_pytorch/lion_pytorch.py
index f96fec6..e025f89 100644
--- a/lion_pytorch/lion_pytorch.py
+++ b/lion_pytorch/lion_pytorch.py
@@ -1,4 +1,3 @@
-from functools import partial
 from typing import Tuple, Optional, Callable
 
 import torch
@@ -34,8 +33,7 @@ def __init__(
         lr: float = 1e-4,
         betas: Tuple[float, float] = (0.9, 0.99),
         weight_decay: float = 0.0,
-        use_triton: bool = False,
-        triton_block_size: int = 1024
+        use_triton: bool = False
     ):
         assert lr > 0.
         assert all([0. <= beta <= 1. for beta in betas])
@@ -54,7 +52,7 @@ def __init__(
 
         if use_triton:
             from lion_pytorch.triton import update_fn as triton_update_fn
-            self.update_fn = partial(triton_update_fn, BLOCK_SIZE = triton_block_size)
+            self.update_fn = triton_update_fn
 
     @torch.no_grad()
     def step(
@@ -67,6 +65,11 @@ def step(
             with torch.enable_grad():
                 loss = closure()
 
+        # address an issue with autotune and in-place updates with triton
+        # on the first .step call, simply do not update parameters in-place, if using triton
+
+        update_kwargs = dict(inplace = False) if self.use_triton and not self.took_first_step else dict()
+
         # update all parameters
 
         for group in self.param_groups:
@@ -88,7 +91,11 @@ def step(
                     lr,
                     wd,
                     beta1,
-                    beta2
+                    beta2,
+                    **update_kwargs
                 )
 
+        if not self.took_first_step:
+            self.took_first_step = True
+
         return loss
diff --git a/lion_pytorch/triton.py b/lion_pytorch/triton.py
index 0615dbc..ca59800 100644
--- a/lion_pytorch/triton.py
+++ b/lion_pytorch/triton.py
@@ -8,18 +8,12 @@
     print('triton is not installed, please install by running `pip install triton -U --pre`')
     exit()
 
-# helper functions
-
-def calc_num_warps(block_size):
-    num_warps = 4
-    if block_size >= 2048:
-        num_warps = 8
-    if block_size >= 4096:
-        num_warps = 16
-    return num_warps
-
 # triton cuda kernel
 
+@triton.autotune(configs = [
+    triton.Config({'BLOCK_SIZE': 128}, num_warps = 4),
+    triton.Config({'BLOCK_SIZE': 1024}, num_warps = 8),
+], key = ['n_elements'])
 @triton.jit
 def update_fn_kernel(
     p_ptr,
@@ -87,20 +81,25 @@ def update_fn(
     wd: float,
     beta1: float,
     beta2: float,
-    inplace: bool = True,
-    BLOCK_SIZE: int = 1024
+    inplace: bool = True
 ):
     assert all([t.is_cuda for t in (p, grad, exp_avg)])
-
     n_elements = p.numel()
 
-    block_size = triton.next_power_of_2(BLOCK_SIZE)
-    num_warps = calc_num_warps(block_size)
-    n_rows = triton.cdiv(n_elements, block_size)
+    grid = lambda meta: (triton.cdiv(n_elements, meta['BLOCK_SIZE']),)    
+
+    # address autotune and in-place update issue
+
+    if not inplace:
+        orig_p = p
+        orig_exp_avg = exp_avg
+
+        p = p.clone()
+        exp_avg = exp_avg.clone()
 
     # call triton cuda kernel
 
-    update_fn_kernel[(n_rows,)](
+    update_fn_kernel[grid](
         p,
         grad,
         exp_avg,
@@ -108,7 +107,11 @@ def update_fn(
         wd,
         beta1,
         beta2,
-        n_elements,
-        num_warps = num_warps,
-        BLOCK_SIZE = BLOCK_SIZE
+        n_elements
     )
+
+    # update if not in-place call
+
+    if not inplace:
+        orig_p.copy_(p)
+        orig_exp_avg.copy_(exp_avg)
diff --git a/setup.py b/setup.py
index 35eb081..1eace6d 100644
--- a/setup.py
+++ b/setup.py
@@ -3,7 +3,7 @@
 setup(
   name = 'lion-pytorch',
   packages = find_packages(exclude=[]),
-  version = '0.1.0',
+  version = '0.0.8',
   license='MIT',
   description = 'Lion Optimizer - Pytorch',
   author = 'Phil Wang',