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Rewrite fgets in asm 

-104 bytes, -1% cycles
This commit is contained in:
Colin Leroy-Mira 2024-01-11 19:31:04 +01:00
parent 57e65a6bf6
commit 1f820d0ae8
4 changed files with 135 additions and 72 deletions
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6
libsrc/apple2/statvfs.s
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@ -6,7 +6,7 @@
.export _statvfs
.import _dio_query_sectsize
.import mli_file_info, pushax, popax, popptr1
.import mli_file_info, pushax, popax, popptr1, pushptr1
.include "zeropage.inc"
.include "apple2.inc"
.include "errno.inc"
@ -45,9 +45,7 @@ _statvfs:
sty vol_sep ; Register '/' index
lda #$00
sta (ptr1),y ; Cut pathname at first slash
: lda ptr1
ldx ptr1+1
jsr pushax
: jsr pushptr1
jsr mli_file_info

68
libsrc/common/fgets.c
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@ -1,68 +0,0 @@
/*
** Ullrich von Bassewitz, 11.08.1998
**
** char* fgets (char* s, int size, FILE* f);
*/
#include <stdio.h>
#include <errno.h>
#include "_file.h"
/*****************************************************************************/
/* Code */
/*****************************************************************************/
char* __fastcall__ fgets (char* s, unsigned size, register FILE* f)
{
register char* p = s;
unsigned i;
int c;
if (size == 0) {
/* Invalid size */
return (char*) _seterrno (EINVAL);
}
/* Read input */
i = 0;
while (--size) {
/* Get next character */
if ((c = fgetc (f)) == EOF) {
/* Error or EOF */
if ((f->f_flags & _FERROR) != 0 || i == 0) {
/* ERROR or EOF on first char */
*p = '\0';
return 0;
} else {
/* EOF with data already read */
break;
}
}
/* One char more */
*p = c;
++p;
++i;
/* Stop at end of line */
if ((char)c == '\n') {
break;
}
}
/* Terminate the string */
*p = '\0';
/* Done */
return s;
}

119
libsrc/common/fgets.s Normal file
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@ -0,0 +1,119 @@
;
; Colin Leroy-Mira, 2024
;
; char* __fastcall__ fgets (char* s, unsigned size, register FILE* f)
;
.export _fgets
.import _fgetc, popptr1, pushptr1, popax, pushax, return0, ___errno
.importzp ptr1, ptr4
.include "errno.inc"
.include "stdio.inc"
.include "_file.inc"
.macpack cpu
terminate_ptr:
lda #$00
tax
.if (.cpu .bitand ::CPU_ISET_65SC02)
sta (ptr4)
.else
tay
sta (ptr4),y
.endif
rts
_fgets:
sta ptr1
stx ptr1+1
jsr popax
sta size
stx size+1
jsr popax
sta ptr4
stx ptr4+1
sta buf
stx buf+1
.if (.cpu .bitand ::CPU_ISET_65SC02)
stz didread
.else
lda #$00 ; We have read nothing yet
sta didread
.endif
; Check size
lda size
ora size+1
bne read_loop
lda #EINVAL
sta ___errno
jmp return0
read_loop:
lda size ; Dec size
bne :+
dec size+1
: dec size
bne :+ ; Check bound
ldx size+1
beq done
: jsr pushptr1 ; Push ptr1 for backup and load it to AX for fgetc
jsr _fgetc ; Read a char
pha
jsr popptr1 ; Get ptr1 back
pla
cpx #<EOF
beq got_eof
ldy #$01
sty didread ; We read at least one char
.if (.cpu .bitand ::CPU_ISET_65SC02)
sta (ptr4)
.else
dey
sta (ptr4),y
.endif
inc ptr4
bne :+
inc ptr4+1
: cmp #$0A ; Stop at \n
beq done
clc
bcc read_loop
got_eof:
lda didread
beq stopped_at_first_char
ldy #_FILE::f_flags
lda (ptr1),y
and #_FERROR
bne stopped_at_first_char
done:
jsr terminate_ptr
ldx #>buf
lda #<buf
rts
stopped_at_first_char:
jmp terminate_ptr
.bss
c: .res 1
buf: .res 2
size: .res 2
didread:.res 1

14
libsrc/runtime/pushptr1.s Normal file
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@ -0,0 +1,14 @@
;
; Colin Leroy-Mira, 2024
;
; CC65 runtime: Push ptr1 to stack.
; A/X destroyed (set to ptr1)
.export pushptr1
.import pushax
.importzp ptr1
pushptr1:
lda ptr1
ldx ptr1+1
jmp pushax