Index: src/runtime/lookup-asm/lookup-asm-ppc-elf.S
==================================================================
--- src/runtime/lookup-asm/lookup-asm-ppc-elf.S
+++ src/runtime/lookup-asm/lookup-asm-ppc-elf.S
@@ -58,15 +58,16 @@
 .size \name, .-\name
 .endm
 
 .macro generate_lookup_super name lookup
 \name:
-	lwz	%r5, 0(%r3)
-	cmpwi	%r5, 0
+	mr	%r5, %r3
+	lwz	%r3, 0(%r3)
+	cmpwi	%r3, 0
 	beq-	ret_nil
 
-	lwz	%r5, 4(%r3)
+	lwz	%r5, 4(%r5)
 	lwz	%r5, 32(%r5)
 
 	b	.Lmain_\lookup
 .type \name, %function
 .size \name, .-\name

Index: src/runtime/lookup-asm/lookup-asm-ppc-macho.S
==================================================================
--- src/runtime/lookup-asm/lookup-asm-ppc-macho.S
+++ src/runtime/lookup-asm/lookup-asm-ppc-macho.S
@@ -54,15 +54,16 @@
 	b	$1
 .endmacro
 
 .macro generate_lookup_super
 $0:
-	lwz	r5, 0(r3)
-	cmpwi	r5, 0
+	mr	r5, r3
+	lwz	r3, 0(r3)
+	cmpwi	r3, 0
 	beq-	ret_nil
 
-	lwz	r5, 4(r3)
+	lwz	r5, 4(r5)
 	lwz	r5, 32(r5)
 
 	b	Lmain_$1
 .endmacro