1 files changed, 15 insertions, 12 deletions
diff --git a/zap/source/amd64/mem/utf20len.S b/zap/source/amd64/mem/utf20len.S
index 5af352b..03f8254 100644
--- a/zap/source/amd64/mem/utf20len.S
+++ b/zap/source/amd64/mem/utf20len.S
@@ -5,31 +5,34 @@
 .globl zap_utf20len
 
 zap_utf20len:
-	# rax: Address of the current character.
-	# rdi: Address of the first character.
-	# rdx: Current character.
+# Address of the current character:
+#define addr  %rax
+# Address of the first character:
+#define start %rdi
+# Current character:
+#define chr   %edx
 
-	movq %rdi,%rax
+	movq start,addr
 
 	# Iterate over the string:
 .loop:
 
 	# Move the character into a register:
-	movl (%rax),%edx
+	movl (addr),chr # chr = *addr
 
 	# Check if we have reached the null-terminator:
-	testl %edx,%edx
-	jz .done # If so, we are done.
+	testl chr,chr # if (chr == 0x0)
+	jz .done      # goto done
 
 	# Continue to the next character:
-	addq $0x4,%rax
-	jmp .loop
+	addq $0x4,addr # addr += 0x4
+	jmp .loop      # goto loop
 
 	# Done:
 .done:
 
 	# Get the length:
-	subq %rdi,%rax
-	shrq $0x2,%rax # Divide by four to get the number of doublewords rather than bytes.
+	subq start,addr # addr -= start
+	shrq $0x2,addr  # addr /= 0x4     // Divide by four to get the number of doublewords rather than bytes.
 
-	ret
+	ret # return addr