From 4bc67f38ded7db00cd36cdab37598ea7130d25e0 Mon Sep 17 00:00:00 2001
From: Gaoxiong <xiong.gao@huawei.com>
Date: Fri, 30 Apr 2021 15:57:29 +0800
Subject: [PATCH] eliminate recursion call

---
 .../graph_kernel/model/graph_split.py         | 58 +++++++++++++------
 1 file changed, 39 insertions(+), 19 deletions(-)

diff --git a/mindspore/_extends/graph_kernel/model/graph_split.py b/mindspore/_extends/graph_kernel/model/graph_split.py
index ec102ecbffa..c2b67eafceb 100644
--- a/mindspore/_extends/graph_kernel/model/graph_split.py
+++ b/mindspore/_extends/graph_kernel/model/graph_split.py
@@ -19,6 +19,34 @@ from .model import PrimLib, Graph, Tensor
 
 class GraphSplitByPattern:
     """Graph splitter"""
+    class ReachTable:
+        """Reachable table"""
+        def __init__(self, size):
+            self.map = []
+            self.alive = set(range(size))
+            for i in range(0, size):
+                self.map.append([False for j in range(0, size)])
+                self.map[i][i] = True
+
+        def reachable(self, x, y):
+            """reachable from x to y"""
+            return self.map[x][y]
+
+        def sync(self, x, y):
+            """sync from y to x"""
+            for i in self.alive:
+                if self.map[y][i] and not self.map[x][i]:
+                    self.map[x][i] = True
+
+        def fuse(self, x, y):
+            """fuse y to x"""
+            for i in self.alive:
+                if self.map[y][i] and not self.map[x][i]:
+                    self.map[x][i] = True
+                if self.map[i][y] and not self.map[i][x]:
+                    self.map[i][x] = True
+            self.alive.remove(y)
+
     class Area:
         """Area"""
         MODE_BASIC = 1
@@ -30,7 +58,7 @@ class GraphSplitByPattern:
                 self.stitch_ops = set()
                 self.stitch_atomic_ops = set()
 
-        def __init__(self, init_op, is_output, unique_id):
+        def __init__(self, init_op, is_output, unique_id, reach_tab):
             self.pattern = PrimLib.iter_type(init_op)
             self.ops = [init_op]
             self.in_relations = dict()  # {area1: relation1, area2: relation2, ...}
@@ -48,8 +76,8 @@ class GraphSplitByPattern:
                         else:
                             _gather_reduce_exclude(to)
                 _gather_reduce_exclude(init_op)
-            self.reach_map = dict()
             self.unique_id = unique_id
+            self.reach_tab = reach_tab
 
         def __str__(self):
             return '<' + '-'.join([op.output.name for op in self.ops]) + '>'
@@ -78,6 +106,8 @@ class GraphSplitByPattern:
             """Link outputs"""
             for input_area, r in self.in_relations.items():
                 input_area.out_relations[self] = r
+            for out, _ in self.out_relations.items():
+                self.reach_tab.sync(self.unique_id, out.unique_id)
 
         def update_stitch_info(self, stitch_info):
             if stitch_info.stitch_ops:
@@ -124,23 +154,12 @@ class GraphSplitByPattern:
             if area.output_excluded:
                 self.output_excluded.update(area.output_excluded)
             self.update_stitch_info(area.stitch_info)
-            for to, reach in area.reach_map.items():
-                if reach and not self.reach_map.get(to, False):
-                    self.reach_map[to] = True
+            self.reach_tab.fuse(self.unique_id, area.unique_id)
 
         def check_acyclic(self, to):
             """Check circle. It returns false if circle exists"""
-            def _reached(area, to):
-                if to.unique_id in area.reach_map:
-                    return area.reach_map[to.unique_id]
-                for out, _ in area.out_relations.items():
-                    if out == to or _reached(out, to):
-                        area.reach_map[to.unique_id] = True
-                        return True
-                area.reach_map[to.unique_id] = False
-                return False
             for out, _ in self.out_relations.items():
-                if out != to and _reached(out, to):
+                if out != to and self.reach_tab.reachable(out.unique_id, to.unique_id):
                     return False
             return True
 
@@ -158,20 +177,21 @@ class GraphSplitByPattern:
         self.graph = graph
         self.areas = []
         self.flags = flags
+        self.reach_tab = self.ReachTable(len(graph.ops))
         area_map = {}
         _, outputs = graph.deduce_parameters()
         idx = 0
         for op in graph.ops:
             is_output = op.output in outputs
-            a = self.Area(op, is_output, idx)
+            a = self.Area(op, is_output, idx, self.reach_tab)
             idx += 1
             self.set_default_mode(a)
             self.areas.append(a)
             area_map[op] = a
         for a in self.areas:
             a.link_input(area_map)
-        for a in self.areas:
-            a.link_output()
+        for i in range(len(self.areas)-1, -1, -1):
+            self.areas[i].link_output()
 
     def set_default_mode(self, area):
         area.mode = self.get_default_mode(area.ops[0])
@@ -260,7 +280,7 @@ class GraphSplitByPattern:
                         break
             if out_reshape_ops:
                 for op in out_reshape_ops:
-                    a = self.Area(op, False, -1)
+                    a = self.Area(op, False, 0, self.reach_tab)
                     self.set_default_mode(a)
                     new_areas.append(a)
                 area.ops = remain_ops