From 9b7ac43643d4d1e55ec5bfa6905199e0064aebeb Mon Sep 17 00:00:00 2001
From: Camden Dixie O'Brien <cdo@wip.sh>
Date: Fri, 8 Nov 2024 16:52:44 +0000
Subject: [PATCH] Implement number parsing

---
 postfix.s | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/postfix.s b/postfix.s
index f33339a..8ee2c57 100644
--- a/postfix.s
+++ b/postfix.s
@@ -39,6 +39,25 @@ wordloop:
 	jmp wordloop
 
 doword:
+	mov $0, %rax
+	mov $0, %rcx
+numloop:
+	## Multiply current value by ten
+	imul $10, %rax
+
+	## Add numeric value of digit
+	movzx (%rsi, %rcx), %rbx
+	sub $0x30, %rbx
+	add %rbx, %rax
+
+	## Increment index and loop if not at end of word
+	inc %rcx
+	cmp %rcx, %rdx
+	jg numloop
+
+	push %rax
+
+endword:
 	## Go back to start if the terminating character (which is in R8)
 	## of the word was a line feed
 	cmp $0x0a, %r8