From b4bc2d9b75c7ecf39f26b717b88384b8a5a9f578 Mon Sep 17 00:00:00 2001
From: "B. Watson" <yalhcru@gmail.com>
Date: Mon, 22 Feb 2016 14:56:05 -0500
Subject: more code shrinkage, 7356 bytes free

---
 cprintul.s | 109 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 cprintul.s

(limited to 'cprintul.s')

diff --git a/cprintul.s b/cprintul.s
new file mode 100644
index 0000000..cf90574
--- /dev/null
+++ b/cprintul.s
@@ -0,0 +1,109 @@
+; cprintul.s - print an unsigned long, int, or char
+
+; Modified from cc65's libsrc/common/ltoa.s
+; Originally by Ullrich von Bassewitz, 11.06.1998
+
+; modified version by B. Watson
+
+; - print the characters with cputs instead of storing in a buffer
+; - rename ultoa => cprintul, change its prototype
+; - add cprintuchar and cprintuint wrappers
+; - got rid of ltoa (don't need it)
+; - hardcode radix to 10
+; - don't need __hextab since we don't do hex (saves 16 bytes)
+; - get rid of dopop subroutine, since the return type is now
+;   void, and we don't take a buffer argument that needs returning.
+
+; void __fastcall__ cprintul(unsigned long value);
+
+        .export         _cprintulong, _cprintuchar, _cprintuint
+        .import         popax, _cputc
+        .importzp       sreg, ptr2
+
+radix = 10
+
+ .ifdef CART_TARGET
+  .segment "HIGHCODE"
+ .else
+  .code
+ .endif
+
+ ; char and int wrappers for cprintulong(). basically these are
+ ; the 'casting' code cc65 would emit any time cprintulong() is
+ ; called with a char or int argument. it happens often enough in
+ ; taipan.c that it's worth doing this way:
+
+ ; cprintulong(1) compiles to 11 bytes:
+ ;  ldx #$00
+ ;  stx sreg
+ ;  stx sreg+1
+ ;  lda #$01
+ ;  jsr _cprintulong
+
+ ; whereas cprintuchar(1) is 5 bytes (saves 6):
+ ;  lda #$01
+ ;  jsr _cprintuchar
+
+ ; cprintuint(1) is 7 bytes (saves 4, add 'ldx #$00' to the above).
+
+ ; the wrappers are 10 bytes together. so long as we remember to *use*
+ ; them, we only have to use cprintuchar() 2 times and/or cprintuint()
+ ; 3 times to start saving bytes.
+
+_cprintuchar:
+ ldx #0
+_cprintuint:
+ pha
+ lda #0
+ sta sreg
+ sta sreg+1
+ pla
+
+ ; main routine
+_cprintulong:
+        ; high word passed to us in sreg
+        ; low word in ptr2
+        sta     ptr2
+        stx     ptr2+1
+
+; Convert to string by dividing and push the result onto the stack
+
+        lda     #$00
+        pha                     ; sentinel
+
+; Divide val/radix -> val, remainder in a
+
+L5:     ldy     #32             ; 32 bit
+        lda     #0              ; remainder
+L6:     asl     ptr2
+        rol     ptr2+1
+        rol     sreg
+        rol     sreg+1
+        rol     a
+        cmp     #radix
+        bcc     L7
+        sbc     #radix
+        inc     ptr2
+L7:     dey
+        bne     L6
+
+        ora     #'0'            ; get ascii character
+        pha                     ; save char value on stack
+
+        lda     ptr2
+        ora     ptr2+1
+        ora     sreg
+        ora     sreg+1
+        bne     L5
+
+; Get the characters from the stack, print them.
+
+@print: pla
+        beq @done               ; exit if sentinel
+        pha
+		  jsr _cputc
+		  pla
+        bne     @print          ; branch always
+
+@done:
+        rts
-- 
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