Index: src/runtime/lookup-asm/lookup-asm-arm64-elf.S
==================================================================
--- src/runtime/lookup-asm/lookup-asm-arm64-elf.S
+++ src/runtime/lookup-asm/lookup-asm-arm64-elf.S
@@ -25,41 +25,52 @@
 .globl objc_msg_lookup_super_stret
 
 .section .text
 .macro generate_lookup name not_found
 \name:
-	cmp	x0, #0
-	beq	ret_nil
+	cbz	x0, ret_nil
+
+	tst	x0, #1
+	bne	.Ltagged_pointer_\name
 
-	ldr	x2, [x0, #0]
+	ldr	x2, [x0]
 	ldr	x2, [x2, #64]
 
 .Lmain_\name:
 #ifdef OF_SELUID24
 	ldrb	w3, [x1, #2]
 	ldr	x2, [x2, x3, lsl #3]
 #endif
 	ldrb	w3, [x1, #1]
 	ldr	x2, [x2, x3, lsl #3]
-	ldrb	w3, [x1, #0]
+	ldrb	w3, [x1]
 	ldr	x2, [x2, x3, lsl #3]
 
-	cmp	x2, #0
-	beq	\not_found
+	cbz	x2, \not_found
 
 	mov	x0, x2
 	ret
+
+.Ltagged_pointer_\name:
+	and	x0, x0, #0xE
+	lsl	x0, x0, #2
+
+	adrp	x2, :got:objc_tagged_pointer_classes
+	ldr	x2, [x2, #:got_lo12:objc_tagged_pointer_classes]
+	ldr	x2, [x2, x0]
+	ldr	x2, [x2, #64]
+
+	b	.Lmain_\name
 .type \name, %function
 .size \name, .-\name
 .endm
 
 .macro generate_lookup_super name lookup
 \name:
 	mov	x2, x0
-	ldr	x0, [x0, #0]
-	cmp	x0, #0
-	beq	ret_nil
+	ldr	x0, [x0]
+	cbz	x0, ret_nil
 
 	ldr	x2, [x2, #8]
 	ldr	x2, [x2, #64]
 
 	b	.Lmain_\lookup