From c74253d081329289dabb4e8269883f9482ad9e4d Mon Sep 17 00:00:00 2001
From: cuz <cuz@b7a2c559-68d2-44c3-8de9-860c34a00d81>
Date: Sun, 28 Nov 2004 18:11:17 +0000
Subject: [PATCH] Replaced fscanf by an assembler version

git-svn-id: svn://svn.cc65.org/cc65/trunk@3313 b7a2c559-68d2-44c3-8de9-860c34a00d81
---
 libsrc/common/.cvsignore |  1 -
 libsrc/common/Makefile   |  2 +-
 libsrc/common/fscanf.c   | 36 ------------------
 libsrc/common/fscanf.s   | 81 ++++++++++++++++++++++++++++++++++++++++
 4 files changed, 82 insertions(+), 38 deletions(-)
 delete mode 100644 libsrc/common/fscanf.c
 create mode 100644 libsrc/common/fscanf.s

diff --git a/libsrc/common/.cvsignore b/libsrc/common/.cvsignore
index b15eaacc8..5e71fc4a5 100644
--- a/libsrc/common/.cvsignore
+++ b/libsrc/common/.cvsignore
@@ -14,7 +14,6 @@ fgets.s
 fputc.s
 fputs.s
 freopen.s
-fscanf.s
 fseek.s
 fsetpos.s
 ftell.s
diff --git a/libsrc/common/Makefile b/libsrc/common/Makefile
index 2aad615ca..86cdd7af5 100644
--- a/libsrc/common/Makefile
+++ b/libsrc/common/Makefile
@@ -44,7 +44,6 @@ C_OBJS =	_afailed.o	\
 		fputc.o		\
 		fputs.o		\
 		freopen.o	\
-                fscanf.o        \
 		fseek.o		\
 		fsetpos.o	\
 		ftell.o		\
@@ -100,6 +99,7 @@ S_OBJS = 	_cwd.o          \
 		fprintf.o	\
 		fread.o		\
 		free.o		\
+                fscanf.o        \
 		fwrite.o	\
 		getcpu.o	\
                 getcwd.o        \
diff --git a/libsrc/common/fscanf.c b/libsrc/common/fscanf.c
deleted file mode 100644
index dae7109a5..000000000
--- a/libsrc/common/fscanf.c
+++ /dev/null
@@ -1,36 +0,0 @@
-/*
- * fscanf.c
- *
- * Ullrich von Bassewitz (uz@cc65.org), 2004-11-26
- *
- */
-
-
-
-#include <stdio.h>
-
-
-
-/*****************************************************************************/
-/*     	    	  		     Code				     */
-/*****************************************************************************/
-
-
-
-int fscanf (FILE* f, const char* format, ...)
-/* Standard C function */
-{
-    va_list ap;
-
-    /* Setup for variable arguments */
-    va_start (ap, format);
-
-    /* Call vfscanf(). Since we know that va_end won't do anything, we will
-     * save the call and return the value directly.
-     */
-    return vfscanf (f, format, ap);
-}
-
-
-
-
diff --git a/libsrc/common/fscanf.s b/libsrc/common/fscanf.s
new file mode 100644
index 000000000..2411f742c
--- /dev/null
+++ b/libsrc/common/fscanf.s
@@ -0,0 +1,81 @@
+;
+; int fscanf (FILE* f, const char* format, ...);
+;
+; Ullrich von Bassewitz, 2004-11-28
+;
+
+	.export	      	_fscanf
+       	.import	       	addysp, decsp4, _vfscanf
+	.importzp	sp, ptr1
+
+	.macpack	generic
+
+; ----------------------------------------------------------------------------
+; Data
+
+.bss
+
+ParamSize: 	.res  	1		; Number of parameter bytes
+
+; ----------------------------------------------------------------------------
+; int fscanf (FILE* f, const char* format, ...)
+; /* Standard C function */
+; {
+;     va_list ap;
+;
+;     /* Setup for variable arguments */
+;     va_start (ap, format);
+;
+;     /* Call vfscanf(). Since we know that va_end won't do anything, we will
+;      * save the call and return the value directly.
+;      */
+;     return vfscanf (f, format, ap);
+; }
+;
+
+.code
+
+_fscanf:
+  	sty	ParamSize		; Number of param bytes passed in Y
+
+; We have to push f and format, both in the order they already have on stack.
+; To make this somewhat more efficient, we will create space on the stack and
+; then do a copy of the complete block instead of pushing each parameter
+; separately. Since the size of the arguments passed is the same as the size
+; of the fixed arguments, this will allow us to calculate the pointer to the
+; fixed size arguments easier (they're just ParamSize bytes away).
+
+      	jsr	decsp4
+
+; Calculate a pointer to the Format argument
+
+      	lda	ParamSize
+      	add	sp
+      	sta	ptr1
+      	ldx	sp+1
+      	bcc	@L1
+      	inx
+@L1:  	stx	ptr1+1
+
+; Now copy both, f and format
+
+      	ldy	#4-1
+@L2:  	lda	(ptr1),y
+      	sta	(sp),y
+      	dey
+      	bpl	@L2
+
+; Load va_list (last and __fastcall__ parameter to vfscanf)
+
+      	lda    	ptr1
+      	ldx    	ptr1+1
+
+; Call vfscanf
+
+	jsr   	_vfscanf
+
+; Cleanup the stack. We will return what we got from vfscanf
+
+	ldy   	ParamSize
+	jmp   	addysp
+
-- 
2.39.5