From 66219401006e845f1a176e6a78c4682bd9de8785 Mon Sep 17 00:00:00 2001
From: "B. Watson" <urchlay@slackware.uk>
Date: Mon, 13 Apr 2026 18:27:08 -0400
Subject: Rewrite most of the txbuf_* functions in asm. 7803 bytes free.

---
 src/irc.h   | 22 ++++++++++++----------
 src/main.c  | 14 --------------
 src/txbuf.s | 33 ++++++++++++++++++++++++++++++++-
 3 files changed, 44 insertions(+), 25 deletions(-)

(limited to 'src')

diff --git a/src/irc.h b/src/irc.h
index 55f1d4d..013798a 100644
--- a/src/irc.h
+++ b/src/irc.h
@@ -10,22 +10,27 @@ extern unsigned char err;
 extern unsigned char trip;
 extern char reconnect_timeout;
 
+/**** these are in txbuf.s: */
+
 /* clears the transmit buffer. */
 void txbuf_init(void);
-
-/* these are in txbuf.s: */
+/* append \x01 (CTCP marker) character */
 void txbuf_append_01(void);
+/* append a space */
 void txbuf_append_spc(void);
+/* append an arbitrary character */
 void txbuf_append_chr(char c);
-
 /* appends a string to the transmit buffer, updates txbuflen. */
 void txbuf_append_str(const char *str);
-/* convenience macro */
-#define txbuf_append_str2(s1, s2) do { txbuf_append_str(s1); txbuf_append_str(s2); } while(0)
-
 /* clears the transmit buffer, then appends a string to it. */
-/* turning into a macro bloats the code */
 void txbuf_set_str(const char *str);
+/* sends a string. clears transmit buffer first, then clears it again on exit. */
+void txbuf_send_str(const char *str);
+
+/****************************/
+
+/* convenience macro */
+#define txbuf_append_str2(s1, s2) do { txbuf_append_str(s1); txbuf_append_str(s2); } while(0)
 
 /* as txbuf_set_str(), but multiple strings. */
 /* making them macros actually makes the code smaller. */
@@ -36,9 +41,6 @@ void txbuf_set_str(const char *str);
    in the buffer, nothing gets sent. */
 void txbuf_send(void);
 
-/* sends a string. clears transmit buffer first, then clears it again on exit. */
-void txbuf_send_str(const char *str);
-
 void print_error(unsigned char err);
 
 /* does exactly what you think */
diff --git a/src/main.c b/src/main.c
index 39763c8..98a45c6 100644
--- a/src/main.c
+++ b/src/main.c
@@ -27,15 +27,6 @@ char reconnect_timeout = 1;
 
 extern void ih();               // defined in intr.s
 
-void txbuf_init(void) {
-	txbuflen = tx_buf[0] = 0;
-}
-
-void txbuf_set_str(const char *str) {
-	txbuf_init();
-	txbuf_append_str(str);
-}
-
 void txbuf_send(void) {
 	/* don't send empty buffer */
 	if(!txbuflen) return;
@@ -51,11 +42,6 @@ void txbuf_send(void) {
 	txbuf_init();
 }
 
-void txbuf_send_str(const char *str) {
-	txbuf_set_str(str);
-	txbuf_send();
-}
-
 int fn_connect(void) {
 	scr_display(SCR_SERVER);
 	scr_print_current("Connecting to: ");
diff --git a/src/txbuf.s b/src/txbuf.s
index dba52c3..6f7b55d 100644
--- a/src/txbuf.s
+++ b/src/txbuf.s
@@ -6,11 +6,25 @@
 
  tx_buf = $a200 ; MUST agree with src/rxtxbuf.h!
 
- .import _txbuflen
+ .import _txbuflen, _txbuf_send
  .export _txbuf_append_chr, _txbuf_append_str
  .export _txbuf_append_spc, _txbuf_append_01
+ .export _txbuf_init, _txbuf_set_str, _txbuf_send_str
  .importzp sreg ; avoid ptr1 & friends, callers may use
 
+;; void txbuf_init(void) {
+;; 	txbuflen = tx_buf[0] = 0;
+;; }
+; this asm implementation is the same size as the compiled code,
+; but it only uses the Y register, which lets its callers avoid
+; having to save the A register before calling it.
+_txbuf_init:
+ ldy #0
+ sty tx_buf
+ sty _txbuflen
+ sty _txbuflen+1
+ rts
+
 _txbuf_append_01:
  lda #$01
  .byte $2c ; BIT abs, skip next instruction
@@ -34,6 +48,14 @@ _txbuf_append_chr:
 ret:
  rts ; always returns with Y == 0
 
+;; void txbuf_set_str(const char *str) {
+;; 	txbuf_init();
+;; 	txbuf_append_str(str);
+;; }
+_txbuf_set_str:
+ jsr _txbuf_init ; remember, this doesn't touch A or X!
+ ; fall through to _txbuf_append_str
+
 ;; void txbuf_append_str(const char *str) {
 ;; 	while(*str) {
 ;; 		txbuf_append_chr(*str++);
@@ -54,3 +76,12 @@ _txbuf_append_str:
  bne @loop
  inc sreg+3
  bne @loop
+ rts ; safety net, the above is really a 'branch always'
+
+;; void txbuf_send_str(const char *str) {
+;; 	txbuf_set_str(str);
+;; 	txbuf_send();
+;; }
+_txbuf_send_str:
+ jsr _txbuf_set_str
+ jmp _txbuf_send
-- 
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