From a97b00ad8d18d836d693c224909b607d2af0c4b1 Mon Sep 17 00:00:00 2001
From: flywind <43030857+xflywind@users.noreply.github.com>
Date: Tue, 12 Jul 2022 19:07:18 +0800
Subject: [PATCH] try to optimize hot spots for orc-booting compiler (#20001)

* optimize hot spots fro orc-booting compiler

* remove GC_ref

* minor

* remove comments

* Revert "minor"

This reverts commit 4965a190a2d6457044faa1442795e55bdad57602.

* emulate cursor
---
 compiler/astalgo.nim | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/compiler/astalgo.nim b/compiler/astalgo.nim
index bc5b7d6e17..22f4257fc5 100644
--- a/compiler/astalgo.nim
+++ b/compiler/astalgo.nim
@@ -18,6 +18,9 @@ import
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
+when not defined(nimHasCursor):
+  {.pragma: cursor.}
+
 proc hashNode*(p: RootRef): Hash
 proc treeToYaml*(conf: ConfigRef; n: PNode, indent: int = 0, maxRecDepth: int = - 1): Rope
   # Convert a tree into its YAML representation; this is used by the
@@ -815,16 +818,21 @@ type
     name*: PIdent
 
 proc nextIdentIter*(ti: var TIdentIter, tab: TStrTable): PSym =
+  # hot spots
   var h = ti.h and high(tab.data)
   var start = h
-  result = tab.data[h]
-  while result != nil:
-    if result.name.id == ti.name.id: break
+  var p {.cursor.} = tab.data[h]
+  while p != nil:
+    if p.name.id == ti.name.id: break
     h = nextTry(h, high(tab.data))
     if h == start:
-      result = nil
+      p = nil
       break
-    result = tab.data[h]
+    p = tab.data[h]
+  if p != nil:
+    result = p # increase the count
+  else:
+    result = nil
   ti.h = nextTry(h, high(tab.data))
 
 proc initIdentIter*(ti: var TIdentIter, tab: TStrTable, s: PIdent): PSym =