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Rewrote fwrite in assembler

git-svn-id: svn://svn.cc65.org/cc65/trunk@1614 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
cuz 2002-11-23 22:51:25 +00:00
parent b948d96206
commit 79396d8acd
5 changed files with 131 additions and 55 deletions

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@ -18,7 +18,6 @@ freopen.s
fseek.s
fsetpos.s
ftell.s
fwrite.s
getchar.s
gets.s
gmtime.s

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@ -30,7 +30,6 @@ C_OBJS = _afailed.o \
fseek.o \
fsetpos.o \
ftell.o \
fwrite.o \
getchar.o \
gets.o \
gmtime.o \
@ -74,6 +73,7 @@ S_OBJS = _fdesc.o \
fopen.o \
fprintf.o \
free.o \
fwrite.o \
getcpu.o \
isalnum.o \
isalpha.o \

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@ -1,51 +0,0 @@
/*
* fwrite.c
*
* Ullrich von Bassewitz, 04.06.1998
*/
#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
#include "_file.h"
size_t fwrite (const void* buf, size_t size, size_t count, FILE* f)
{
int bytes;
/* Is the file open? */
if ((f->f_flags & _FOPEN) == 0) {
_errno = EINVAL; /* File not open */
return 0;
}
/* Did we have an error */
if ((f->f_flags & _FERROR) != 0) {
/* Cannot write to stream */
return 0;
}
/* How many bytes to write? */
bytes = size * count;
if (bytes) {
/* Write the data. */
if (write (f->f_fd, buf, bytes) == -1) {
/* Write error */
f->f_flags |= _FERROR;
return 0;
}
}
/* Don't waste time with expensive calculations, assume the write was
* complete and return the count of items.
*/
return count;
}

129
libsrc/common/fwrite.s Normal file
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@ -0,0 +1,129 @@
;
; Ullrich von Bassewitz, 22.11.2002
;
; size_t __fastcall__ fwrite (const void* buf, size_t size, size_t count, FILE* f);
; /* Write to a file */
;
.export _fwrite
.import _write
.import pushax, incsp6, addysp, ldaxysp, pushwysp, return0
.import tosumulax, tosudivax
.importzp ptr1
.include "errno.inc"
.include "_file.inc"
; ------------------------------------------------------------------------
; Code
.proc _fwrite
; Save f and place it into ptr1
sta f
sta ptr1
stx f+1
stx ptr1+1
; Check if the file is open
ldy #_FILE_f_flags
lda (ptr1),y
and #_FOPEN ; Is the file open?
bne @L2 ; Branch if yes
; File not open
lda #EINVAL
sta __errno
lda #0
sta __errno+1
@L1: jsr incsp6
jmp return0
; Check if the stream is in an error state
@L2: lda (ptr1),y ; get f->f_flags again
and #_FERROR
bne @L1
; Build the stackframe for write()
ldy #_FILE_f_fd
lda (ptr1),y
ldx #$00
jsr pushax ; f->f_fd
ldy #9
jsr pushwysp ; buf
; Stack is now: buf/size/count/f->fd/buf
; Calculate the number of bytes to write: count * size
ldy #7
jsr pushwysp ; count
ldy #9
jsr ldaxysp ; Get size
jsr tosumulax ; count * size -> a/x
; Check if the number of bytes is zero. Don't call write in this case
cpx #0
bne @L3
cmp #0
bne @L3
; The number of bytes to write is zero, just return count
ldy #5
jsr ldaxysp ; Get count
ldy #10
jmp addysp ; Drop params, return
; Call write(). This will leave the original 3 params on the stack
@L3: jsr pushax
jsr _write
; Check for errors in write
cpx #$FF
bne @L4
cmp #$FF
bne @L4
; Error in write. Set the stream error flag and bail out. _oserror and/or
; errno are already set by write().
lda f
sta ptr1
lda f+1
sta ptr1+1
ldy #_FILE_f_fd
lda (ptr1),y
ora #_FERROR
sta (ptr1),y
bne @L1 ; Return zero
; Write was ok. Return the number of items successfully written. Since we've
; checked for bytes == 0 above, size cannot be zero here, so the division is
; safe.
@L4: jsr pushax ; Push number of bytes written
ldy #5
jsr ldaxysp ; Get size
jsr tosudivax ; bytes / size -> a/x
jmp incsp6 ; Drop params, return
.endproc
; ------------------------------------------------------------------------
; Data
.bss
f: .res 2

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@ -61,8 +61,7 @@ out:
lda (ptr1),y
tax
dey
lda (ptr1),y
jsr pushax ; Push D->ptr
lda (ptr1),y ; Load D->ptr
jsr _fwrite
sta ptr2 ; Save function result
stx ptr2+1