1 files changed, 14 insertions, 10 deletions
diff --git a/zap/source/amd64/mem/memfill.S b/zap/source/amd64/mem/memfill.S
index e563b55..c38eec8 100644
--- a/zap/source/amd64/mem/memfill.S
+++ b/zap/source/amd64/mem/memfill.S
@@ -5,26 +5,30 @@
 .globl zap_memfill
 
 zap_memfill:
-	# rdi: Address of the current element.
-	# rsi: Address of the element after the last element.
-	# rdx: Byte value.
+# Address of the current element:
+#define addr     %rdi
+# Address of the element after the last element:
+#define afterbuf %rsi
+# Byte value:
+#define val      %dl
 
-	addq %rdi,%rsi
+	addq addr,afterbuf # afterbuf += addr // afterbuf contains the number of bytes
 
 	# Iterate over buffer:
 .loop:
 
 	# Check if we have reached the final element:
-	cmpq %rdi,%rsi
-	je .done # Exit loop if we have.
+	cmpq addr,afterbuf # if (addr == afterbuf)
+	je .done           # goto done
 
 	# Set the value of the current element:
-	movb %dl,(%rdi)
+	movb val,(addr) # *addr = val
 
 	# Continue to next element:
-	incq %rdi
-	jmp .loop
+	incq addr # ++addr
+	jmp .loop # goto loop
 
 	# Finish:
 .done:
-	ret
+
+	ret # return