From a92a96fadb56067c3e550e7f55df4a76e60fdb27 Mon Sep 17 00:00:00 2001
From: Jacek Sieka <arnetheduck@gmail.com>
Date: Mon, 15 Dec 2025 13:19:56 +0100
Subject: [PATCH] Align treetab hash with equivalence (#25354)

In particular, hash `typ` for `nkType`, `nkNilLit` or they end up
generating collisions

<img width="989" height="612" alt="image"
src="https://github.com/user-attachments/assets/a5c6366f-1214-443e-98d5-52ce95fc3555"
/>
---
 compiler/treetab.nim | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

diff --git a/compiler/treetab.nim b/compiler/treetab.nim
index 1fd539f0f2..b8b0f7b191 100644
--- a/compiler/treetab.nim
+++ b/compiler/treetab.nim
@@ -21,20 +21,13 @@ proc hashTree*(n: PNode): Hash =
     return
   result = ord(n.kind)
   case n.kind
-  of nkEmpty, nkNilLit, nkType:
-    discard
-  of nkIdent:
-    result = result !& n.ident.h
-  of nkSym:
-    result = result !& n.sym.id
-  of nkCharLit..nkUInt64Lit:
-    if (n.intVal >= low(int)) and (n.intVal <= high(int)):
-      result = result !& int(n.intVal)
-  of nkFloatLit..nkFloat64Lit:
-    if (n.floatVal >= - 1000000.0) and (n.floatVal <= 1000000.0):
-      result = result !& toInt(n.floatVal)
-  of nkStrLit..nkTripleStrLit:
-    result = result !& hash(n.strVal)
+  of nkEmpty: discard
+  of nkSym: result = result !& n.sym.id
+  of nkIdent: result = result !& n.ident.h
+  of nkCharLit..nkUInt64Lit: result = result !& hash(n.intVal)
+  of nkFloatLit..nkFloat64Lit: result = result !& hash(cast[uint64](n.floatVal))
+  of nkStrLit..nkTripleStrLit: result = result !& hash(n.strVal)
+  of nkType, nkNilLit: result = result !& hash(n.typ.itemId)
   else:
     for i in 0..<n.len:
       result = result !& hashTree(n[i])
@@ -53,7 +46,6 @@ proc treesEquivalent(a, b: PNode; ignoreTypes: bool): bool =
     of nkCharLit..nkUInt64Lit: result = a.intVal == b.intVal
     of nkFloatLit..nkFloat64Lit:
       result = cast[uint64](a.floatVal) == cast[uint64](b.floatVal)
-      #result = a.floatVal == b.floatVal
     of nkStrLit..nkTripleStrLit: result = a.strVal == b.strVal
     of nkType, nkNilLit:
       result = a.typ == b.typ