Serial: Optimize TryToSend

We don't need to reload SendFreeCnt each time we loop to wait for the ACIA to be ready.
2023-08-30 21:28:09 +02:00
parent c674b7ced4
commit 3f3b6123b9
7 changed files with 43 additions and 41 deletions
--- a/libsrc/c128/ser/c128-swlink.s
+++ b/libsrc/c128/ser/c128-swlink.s
@@ -466,25 +466,25 @@ NmiHandler:
        sta     tmp1            ; Remember tryHard flag
@L0:    lda     SendFreeCnt
        cmp     #$ff
-        beq     @L3             ; Bail out
+        beq     @L2             ; Bail out

 ; Check for flow stopped

@L1:    lda     Stopped
-        bne     @L3             ; Bail out
+        bne     @L2             ; Bail out

 ; Check that swiftlink is ready to send

-@L2:    lda     ACIA_STATUS
+        lda     ACIA_STATUS
        and     #$10
-        bne     @L4
+        bne     @L3
        bit     tmp1            ;keep trying if must try hard
-        bmi     @L0
-@L3:    rts
+        bmi     @L1
+@L2:    rts

 ; Send byte and try again

-@L4:    ldx     SendHead
+@L3:    ldx     SendHead
        lda     SendBuf,x
        sta     ACIA_DATA
        inc     SendHead