From 0e4ad432dd61216449603802e36e991ed0cb2154 Mon Sep 17 00:00:00 2001
From: Stas Boukarev <stassats@gmail.com>
Date: Wed, 18 Mar 2026 18:19:42 +0300
Subject: [PATCH] remove-duplicates: use hash-tables for :test #'=

---
 src/code/seq.lisp    |  4 +++-
 tests/hash.pure.lisp |  1 +
 tests/seq.pure.lisp  | 12 +++++++++++-
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/code/seq.lisp b/src/code/seq.lisp
index 0f64817f8..72d81c7c7 100644
--- a/src/code/seq.lisp
+++ b/src/code/seq.lisp
@@ -2549,7 +2549,9 @@ many elements are copied."
         ((eq fun #'string=)
          (make-hash-table :test #'string= :hash-function #'string=-hash  :size size))
         ((eq fun #'string-equal)
-         (make-hash-table :test #'string-equal :hash-function #'string-equal-hash :size size))))
+         (make-hash-table :test #'string-equal :hash-function #'string-equal-hash :size size))
+        ((eq fun #'=)
+         (make-hash-table :test #'= :hash-function #'psxhash :size size))))
 
 ;;; Remove duplicates from a list. If from-end, remove the later duplicates,
 ;;; not the earlier ones. Thus if we check from-end we don't copy an item
diff --git a/tests/hash.pure.lisp b/tests/hash.pure.lisp
index fefe3c364..e14b0e5a9 100644
--- a/tests/hash.pure.lisp
+++ b/tests/hash.pure.lisp
@@ -477,6 +477,7 @@
     (unwind-protect
          (let ((transformed-cases '((integer sb-impl::integer-sxhash)
                                     (number sb-impl::number-sxhash)
+                                    #-sb-devel ;; where sb-impl::instance-sxhash is inlined
                                     (sb-kernel:instance sb-impl::instance-sxhash)))
                (inlined-cases '(single-float double-float fixnum)))
            (loop for (type . hasher) in transformed-cases
diff --git a/tests/seq.pure.lisp b/tests/seq.pure.lisp
index a9595c8f2..7eaa25266 100644
--- a/tests/seq.pure.lisp
+++ b/tests/seq.pure.lisp
@@ -76,7 +76,7 @@
     (assert (equalp (remove-duplicates orig :start 3 :end 9) '(0 1 2 0 1 2 0 1 2)))
     (assert (equalp (delete-duplicates orig :start 3 :end 9) '(0 1 2 0 1 2 0 1 2)))))
 
-(with-test (:name (remove-duplicates delete-duplicates :key))
+(with-test (:name (remove-duplicates :key))
   (let* ((negative (loop :for i :from 1 :to 11 :collect (- i)))
          (positive (loop :for i :from 1 :to 11 :collect i))
          (combined (append negative positive))
@@ -86,6 +86,16 @@
     (assert (equalp (coerce positive 'vector) (remove-duplicates vector :key #'abs)))
     (assert (equalp (coerce negative 'vector) (remove-duplicates vector :key #'abs :from-end t)))))
 
+(with-test (:name :remove-duplicates-test-=)
+  (let* ((negative (loop :for i :from 1 :to 11 :collect (- i)))
+         (positive (loop :for i :from 1 :to 11 :collect (float i)))
+         (combined (append negative positive))
+         (vector (coerce combined 'vector)))
+    (assert (equal positive (remove-duplicates combined :key #'abs :test #'=)))
+    (assert (equal negative (remove-duplicates combined :key #'abs :from-end t :test #'=)))
+    (assert (equalp (coerce positive 'vector) (remove-duplicates vector :key #'abs :test #'=)))
+    (assert (equalp (coerce negative 'vector) (remove-duplicates vector :key #'abs :from-end t :test #'=)))))
+
 ;;; tests of COUNT
 (with-test (:name (count))
   (assert (= 1 (count 1 '(1 2 3))))